Merck Announces New Data Analyses for VICTRELIS™ (Boceprevir) will be Presented at The International Liver CongressTM / 2011 EASL Annual Meeting

WHITEHOUSE STATION, N.J.--(BUSINESS WIRE)--Merck (NYSE: MRK), known as MSD outside of the United States and Canada, announced today that several new data analyses from Phase III studies of VICTRELIS^™ (boceprevir), its investigational oral hepatitis C protease inhibitor, will be presented at The International Liver Congress^TM / 46^th European Association for the Study of the Liver (EASL) annual meeting. The meeting will be held from March 30 – April 3 in Berlin. In total, more than 20 abstracts highlighting Merck medicines and investigational therapies for chronic hepatitis C virus (HCV) infection will be presented, including 3 oral presentations and 17 posters for VICTRELIS.

Presented for the first time will be final results from a Phase III study of VICTRELIS administered in combination with Pegasys^® (peginterferon alfa-2a) and ribavirin in adult patients with chronic HCV genotype 1 infection who were non-responders or relapsers to previous pegylated interferon and ribavirin therapy.

The EASL presentations will also include new analyses of the pivotal Phase III data for VICTRELIS administered in combination with PEGINTRON^® (peginterferon alfa-2b) and ribavirin from the HCV SPRINT-2 and HCV RESPOND-2 studies:

• Response-guided therapy with VICTRELIS in combination with current standard therapy among patients with chronic HCV genotype 1, including special populations such as those with advanced fibrosis / cirrhosis;
• Overall safety profile of VICTRELIS administered in combination with current standard therapy for chronic HCV; and
• Potential predictive factors for chronic HCV treatment success, including response following 4 weeks of lead-in therapy and IL28B polymorphism.

The abstracts were published today and can be accessed on the EASL website. For program information, please visit http://www2.kenes.com/liver-congress/Pages/Home.aspx.

VICTRELIS (Boceprevir) Oral Presentations

Parallel Session: HCV Therapy, Thursday, March 31, 17:00 – 19:00, Hall 1

Boceprevir in Addition to Standard of Care Enhanced SVR in Hepatitis C Virus (HCV) Genotype-1 with Advanced Fibrosis/Cirrhosis: Subgroup Analysis of SPRINT-2 and RESPOND-2 Studies; S. Bruno et al. 17:15 – 17:30 CET

Boceprevir Resistance-Associated Variants (RAVS) are Observed More Frequently in HCV (Gt1)-Infected Patients with Poor Response to Peginterferon Alfa-2b/Ribavirin; S. Zeuzem et al. 17:45 – 18:00 CET

IL28B Polymorphism Predicts Virologic Response in Patients with Hepatitis C Genotype 1 Treated with Boceprevir (BOC) Combination Therapy. F. Poordad et al. 18:30 – 18:45 CET

VICTRELIS (Boceprevir) Key Poster Presentations

High Sustained Virologic Response (SVR) Among Genotype 1 Previous Non-Responders and Relapsers to Peginterferon/Ribavirin When Re-Treated With Boceprevir Plus Peginterferon Alfa-2A/Ribavirin. S. Flamm et al. Late-Breaker Abstract 1366. Thursday, March 31.

Response-Guided Therapy with Boceprevir Plus Peginterferon Alfa-2b/Ribavirin Reduces Duration in Naive and Peginterferon Alfa-2b/Ribavirin Previous-Treatment-Failure Patients with HCV Genotype 1. M.P. Manns et al. Abstract 448. Thursday, March 31.

Overall Safety Profile of Boceprevir Plus Peginterferon Alfa-2b/Ribavirin. M.P. Manns et al. Abstract 449. Thursday, March 31.

Four-Week Therapy with Peginterferon Alfa-2b/Ribavirin Effectively Predicts Sustained Virologic Response in Treatment-Naïve and Previous-Treatment-Failure Patients with HCV-1 Treated with Boceprevir Plus Peginterferon Alfa-2b/Ribavirin. J.M. Viering et al. Abstract 481. Thursday, March 31.

Utility of Historical Data Compared to Lead-In Response in Predicting Sustained Virologic Response in Non-Responders and Relapsers to Peginterferon/Ribavirin When Re-Treated With Boceprevir+Peginterferon Alfa-2b/Ribavirin (P/R). R. Esteban et al. Abstract 418. Thursday, March 31.

About the HCV RESPOND-2 and HCV SPRINT-2 Studies

The HCV RESPOND-2 study in treatment-failure patients and the HCV SPRINT-2 study in previously untreated patients each evaluated two treatment strategies with VICTRELIS administered in combination with PEGINTRON and ribavirin to assess the ability to improve sustained virologic response (SVR) ¹ and potentially shorten overall treatment duration compared to treatment with PEGINTRON and ribavirin alone:

• Response-guided therapy, in which treatment-failure patients with undetectable virus at week 8 were able to stop all treatment at 36 weeks, and in which previously untreated

• patients with undetectable virus during weeks 8 through 24 were able to stop all treatment at 28 weeks; and
• 48 weeks of treatment (4-week PEGINTRON and ribavirin lead-in followed by the addition of VICTRELIS for 44 weeks).

In both studies, all patients were treated with a 4-week lead-in of PEGINTRON (1.5 mcg/kg/week) and an investigational dose of ribavirin (600-1,400 mg/day), followed by the addition of VICTRELIS (800 mg three times a day).

As previously reported, the U.S. Food and Drug Administration has granted priority review status to the New Drug Application (NDA) for VICTRELIS and the Marketing Authorization Application (MAA) for VICTRELIS has been accepted for accelerated assessment by the European Medicines Agency. Data in the NDA and MAA have been provided in support of the proposed use of boceprevir for the treatment of chronic HCV genotype 1 infection, in combination with peginterferon alpha and ribavirin, in adult patients with compensated liver disease who are previously untreated or who have failed previous therapy.

Merck is committed to building on its strong legacy in the field of viral hepatitis by continuing to discover, develop and deliver vaccines and medicines to help prevent and treat viral hepatitis. In hepatitis C, company researchers developed the first approved therapy for chronic HCV in 1991 and the first combination therapy in 1998. 2011 marks the 10-year anniversary of the introduction of PEGINTRON and ribavirin in combination therapy, a current standard therapy for chronic HCV worldwide. In addition to ongoing studies with VICTRELIS, extensive research efforts are underway to develop additional innovative oral therapies for viral hepatitis care.

About PEGINTRON

PEGINTRON is indicated for use in combination with ribavirin for the treatment of chronic hepatitis C in patients 3 years of age and older with compensated liver disease.

The following points should be considered when initiating therapy with PEGINTRON in combination with ribavirin: (1) These indications are based on achieving undetectable HCV-RNA after treatment for 24 or 48 weeks and maintaining a Sustained Virologic Response (SVR) 24 weeks after the last dose. (2) Patients with the following characteristics are less likely to benefit from re-treatment after failing a course of therapy: previous nonresponse, previous pegylated interferon treatment, significant bridging fibrosis or cirrhosis, and genotype 1 infection. (3) No safety and efficacy data are available for treatment of longer than one year.

PEGINTRON is also indicated for use alone for the treatment of chronic hepatitis C in patients with compensated liver disease previously untreated with interferon alpha and who are at least 18 years of age.

The following points should be considered when initiating therapy with PEGINTRON alone: Combination therapy with ribavirin is preferred over PEGINTRON monotherapy unless there are contraindications to, or significant intolerance of, ribavirin. Combination therapy provides substantially better response rates than monotherapy.

Selected Safety Information on PEGINTRON

WARNING: RISK OF SERIOUS DISORDERS AND RIBAVIRIN-ASSOCIATED EFFECTS

Alpha interferons, including PEGINTRON, may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory evaluations. Patients with persistently severe or worsening signs or symptoms of these conditions should be withdrawn from therapy. In many, but not all cases, these disorders resolve after stopping PEGINTRON therapy.

Use with Ribavirin: Ribavirin may cause birth defects and death of the unborn child. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients. Ribavirin causes hemolytic anemia. The anemia associated with ribavirin therapy may result in a worsening of cardiac disease. Ribavirin is genotoxic and mutagenic and should be considered a potential carcinogen.

Contraindications

PEGINTRON is contraindicated in patients with known hypersensitivity reactions such as urticaria, angioedema, bronchoconstriction, anaphylaxis, Stevens-Johnson syndrome and toxic epidermal necrolysis to interferon alpha or any other component of the product, autoimmune hepatitis, and hepatic decompensation (Child-Pugh score greater than 6 [class B and C]) in cirrhotic CHC patients before or during treatment. PEGINTRON/ribavirin combination therapy is additionally contraindicated in women who are pregnant or may become pregnant, men whose female partners are pregnant, patients with hemoglobinopathies (e.g., thalassemia major, sickle-cell anemia), and patients with creatinine clearance less than 50 mL per min.

Pregnancy

Ribavirin therapy should not be started until a report of a negative pregnancy test has been obtained immediately prior to planned initiation of therapy. Patients should use at least two effective forms of contraception and have monthly pregnancy tests during therapy and for six months after completion of therapy. If this drug is used during pregnancy, or if a patient becomes pregnant, the patient should be apprised of the potential hazard to a fetus. A Ribavirin Pregnancy Registry has been established to monitor maternal-fetal outcomes of pregnancies in female patients and female partners of male patients exposed to ribavirin during treatment, and for six months following cessation of treatment. Physicians and patients are encouraged to report such cases by calling 1-800-593-2214.

Patients with the following conditions should be closely monitored and may require dose reduction or discontinuation of therapy:

• Hemolytic anemia with ribavirin
• Neuropsychiatric events
• History of significant or unstable cardiac disease
• Hypothyroidism, hyperthyroidism, hyperglycemia, diabetes mellitus that cannot be effectively treated by medication
• New or worsening ophthalmologic disorders
• Ischemic and hemorrhagic cerebrovascular events
• Severe decreases in neutrophil or platelet counts
• History of autoimmune disorders
• Pancreatitis and ulcerative or hemorrhagic/ischemic colitis and pancreatitis
• Pulmonary infiltrates or pulmonary function impairment
• Child-Pugh score greater than 6 (Class B and C)
• Increased creatinine levels in patients with renal insufficiency
• Serious, acute hypersensitivity reactions and cutaneous eruptions
• Dental/periodontal disorders reported with combination therapy
• Hypertriglyceridemia may result in pancreatitis (e.g., triglycerides greater than 1000 mg/dL)
• Weight loss and growth inhibition reported with combination therapy in pediatric patients.

Life-threatening or fatal neuropsychiatric events, including suicidal and homicidal ideation, depression, relapse of drug addiction/overdose, and aggressive behavior, sometimes directed towards others, have occurred in patients with and without a previous psychiatric disorder during PEGINTRON treatment and follow-up.

Adverse Events

Serious adverse reactions have occurred in approximately 12 percent of subjects in clinical trials. The most common serious events occurring in subjects treated with PEGINTRON and ribavirin were depression and suicidal ideation, each occurring at a frequency of less than 1 percent. The most common fatal events occurring in subjects treated with PEGINTRON and ribavirin were cardiac arrest, suicidal ideation, and suicide attempt, all occurring in less than 1 percent of subjects.

The incidence of serious adverse reactions was comparable between PEGINTRON monotherapy (about 12 percent) and PEGINTRON/ribavirin combination therapy weight-based (12 percent) or flat-dose (17 percent). In many but not all cases, adverse reactions resolved after dose reduction or discontinuation of therapy. Some patients experienced ongoing or new serious adverse reactions during the 6-month follow-up period. In a study with PEGINTRON/ribavirin (weight-based) combination therapy in adult patients, anemia with weight-based dosing occurred at an increased rate (29 percent vs. 19 percent); however, the majority of these cases were mild and responded to dose reductions. The incidence of serious adverse reactions reported for the weight-based ribavirin group was 12 percent. There were 31 deaths in clinical trials which occurred during treatment or during follow-up. Of the deaths, 19 were patients on either PEGINTRON or PEGINTRON/ribavirin combination therapy and three occurred during the follow-up period but had been on PEGINTRON/ribavirin combination therapy.

Additional serious adverse reactions seen in clinical trials at a frequency of equal to or less than 1 percent included psychosis, aggressive reaction, relapse of drug addiction/overdose; nerve palsy (facial, oculomotor); cardiomyopathy, angina, pericardial effusion, retinal ischemia, retinal artery or vein thrombosis, blindness, decreased visual acuity, optic neuritis, transient ischemic attack, supraventricular arrhythmias, loss of consciousness; neutropenia, infection (sepsis, pneumonia, abscess, cellulitis); emphysema, bronchiolitis obliterans, pleural effusion, gastroenteritis, pancreatitis, gout, hyperglycemia, hyperthyroidism and hypothyroidism, autoimmune thrombocytopenia with or without purpura, rheumatoid arthritis, interstitial nephritis, lupus-like syndrome, sarcoidosis, aggravated psoriasis, urticaria, injection site necrosis, vasculitis, and phototoxicity.

Greater than 96 percent of all subjects in clinical trials experienced one or more adverse events. Most common adverse reactions (greater than 40 percent) in adult patients receiving either PEGINTRON or PEGINTRON/ribavirin are injection site inflammation/reaction, fatigue/asthenia, headache, rigors, fevers, nausea, myalgia, and anxiety/emotional lability/irritability.

The adverse reaction profile was similar between weight-based and flat-dose PEGINTRON/ribavirin therapies. Weight-based PEGINTRON/ribavirin dosing resulted in increased rates of anemia. Most common adverse reactions with PEGINTRON/ribavirin (weight-based) therapy were psychiatric, which occurred among 68-69 percent of patients and included depression, irritability, and insomnia, each reported by approximately 30-40 percent of subjects in all treatment groups. Suicidal behavior (ideation, attempts, and suicides) occurred in 2 percent of all patients during treatment or during follow-up after treatment cessation. Other common reactions included injection site reactions, fatigue/ asthenia, headache, rigors, fever, nausea, myalgia, anxiety/emotional lability/irritability. The severity of some of these systemic symptoms tends to decrease as treatment continues.

Subjects receiving PEGINTRON/ribavirin as re-treatment after failing a previous interferon combination regimen reported adverse reactions similar to previous treatment-naïve patients receiving this regimen.

In general, the adverse reaction profile in the pediatric population was similar to that observed in adults. Most common adverse reactions (greater than 25 percent) in pediatric patients receiving PEGINTRON/ribavirin are pyrexia, headache, neutropenia, fatigue, anorexia, injection site erythema, abdominal pain, and vomiting.

Please see full prescribing information at http://www.spfiles.com/pipeg-intron.pdf.

About Merck

Today's Merck is a global healthcare leader working to help the world be well. Merck is known as MSD outside the United States and Canada. Through our prescription medicines, vaccines, biologic therapies, and consumer care and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to healthcare through far-reaching policies, programs and partnerships. For more information, visit www.merck.com.

Forward-Looking Statement

This news release includes “forward-looking statements” within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. Such statements may include, but are not limited to, statements about the benefits of the merger between Merck and Schering-Plough, including future financial and operating results, the combined company’s plans, objectives, expectations and intentions and other statements that are not historical facts. Such statements are based upon the current beliefs and expectations of Merck’s management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forward-looking statements.

The following factors, among others, could cause actual results to differ from those set forth in the forward-looking statements: the possibility that the expected synergies from the merger of Merck and Schering-Plough will not be realized, or will not be realized within the expected time period; the impact of pharmaceutical industry regulation and health care legislation; the risk that the businesses will not be integrated successfully; disruption from the merger making it more difficult to maintain business and operational relationships; Merck’s ability to accurately predict future market conditions; dependence on the effectiveness of Merck’s patents and other protections for innovative products; the risk of new and changing regulation and health policies in the U.S. and internationally and the exposure to litigation and/or regulatory actions.

Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in Merck’s 2010 Annual Report on Form 10-K and the company’s other filings with the Securities and Exchange Commission (SEC) available at the SEC’s Internet site (www.sec.gov).

Please see attached Prescribing Information, Medication Guide, and Instructions for Use including Boxed Warning for PEGINTRON. The Prescribing Information, Medication Guide, and Instructions for Use are also available at http://www.spfiles.com/pipeg-intron.pdf, http://www.spfiles.com/mgpeg-intron.pdf and http://www.spfiles.com/ifupeg-intron.pdf.

Endnote

1 SVR, the protocol specified primary efficacy endpoint, is defined as achievement of undetectable HCV-RNA at 24 weeks after the end of treatment in all randomized patients treated with any study medication. Per protocol, if a patient did not have a 24-week post-treatment assessment, the patient’s 12-week post-treatment assessment was utilized.

VICTRELIS^™ and PEGINTRON^® are trademarks of Schering Corp., a subsidiary of Merck & Co., Inc., Whitehouse Station, N.J., USA

Pegasys^® is a trademark of its respective owner and is not a trademark of Merck & Co., Inc., Whitehouse Station, N.J., USA.

HIGHLIGHTS OF PRESCRIBING INFORMATION

These highlights do not include all the information needed to use

PegIntron safely and effectively. See full prescribing information for PegIntron.

PegIntron (Peginterferon alfa-2b) Injection, Powder for Solution for Subcutaneous Use

Initial U.S. Approval: 2001

WARNING: RISK OF SERIOUS DISORDERS AND RIBAVIRIN-ASSOCIATED EFFECTS

See full prescribing information for complete boxed warning.

• May cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Monitor closely and withdraw therapy with persistently severe or worsening signs or symptoms of the above disorders. (5)

Use with Ribavirin

• Ribavirin may cause birth defects and fetal death; avoid pregnancy in female patients and female partners of male patients. (5.1)
• Ribavirin is a potential carcinogen. (5.1, 13.1)

RECENT MAJOR CHANGES

Warnings and Precautions, Pulmonary Disorders (5.11) [2/2011]

INDICATIONS AND USAGE

PegIntron is an antiviral indicated for

• Combination therapy with REBETOL (ribavirin):
  Chronic Hepatitis C (CHC) in patients ≥3 years with compensated liver disease. (1.1)
  Patients with the following characteristics are less likely to benefit from re-treatment after failing a course of therapy: previous nonresponse, previous pegylated interferon treatment, significant bridging fibrosis or cirrhosis, and genotype 1 infection. (1.1)

• Monotherapy: CHC in patients (≥18 years) with compensated liver disease previously untreated with interferon alpha. (1.1)

DOSAGE AND ADMINISTRATION

• PegIntron is administered by subcutaneous injection.

	PegIntron Dose (Adults)^*	PegIntron Dose (Pediatric Patients)	REBETOL Dose^* (Adults)	REBETOL Dose (Pediatric Patients)
PegIntron/ REBETOL Combination Therapy (2.1)	1.5 mcg/kg/ week	60 mcg/m^2/ week	800-1400 mg orally daily with food	15 mg/kg/day orally with food in 2 divided doses

* Refer to Tables 1-7 of the full Prescribing Information.

• Dose reduction is recommended in patients experiencing certain adverse reactions or renal dysfunction. (2.3, 2.5)

DOSAGE FORMS AND STRENGTHS

Single-use vial (with 1.25 mL diluent) and REDIPEN® (3):

• 50 mcg per 0.5 mL, 80 mcg per 0.5 mL, 120 mcg per 0.5 mL, 150 mcg per 0.5 mL.

CONTRAINDICATIONS

• Known hypersensitivity reactions, such as urticaria, angioedema, bronchoconstriction, anaphylaxis, Stevens-Johnson syndrome, and toxic epidermal necrolysis to interferon alpha or any other product component. (4)
• Autoimmune hepatitis. (4)
• Hepatic decompensation (Child-Pugh score >6 [class B and C]) in cirrhotic CHC patients before or during treatment. (4)

Additional contraindications for combination therapy with ribavirin:

• Pregnant women and men whose female partners are pregnant. (4, 8.1)
• Hemoglobinopathies (e.g., thalassemia major, sickle-cell anemia). (4)
• Creatinine clearance <50 mL/min. (4)

WARNINGS AND PRECAUTIONS

• Birth defects and fetal death with ribavirin: Patients must have a negative pregnancy test prior to therapy, use at least 2 forms of contraception, and undergo monthly pregnancy tests. (5.1)

Patients exhibiting the following conditions should be closely monitored and may require dose reduction or discontinuation of therapy:

• Hemolytic anemia with ribavirin. (5.1)
• Neuropsychiatric events. (5.2)
• History of significant or unstable cardiac disease. (5.3)
• Hypothyroidism, hyperthyroidism, hyperglycemia, diabetes mellitus that cannot be effectively treated by medication. (5.4)
• New or worsening ophthalmologic disorders. (5.5)
• Ischemic and hemorrhagic cerebrovascular events. (5.6)
• Severe decreases in neutrophil or platelet counts. (5.7)
• History of autoimmune disorders. (5.8)
• Pancreatitis and ulcerative or hemorrhagic/ischemic colitis and pancreatitis. (5.9, 5.10)
• Pulmonary infiltrates or pulmonary function impairment. (5.11)
• Child-Pugh score >6 (class B and C). (4, 5.12)
• Increased creatinine levels in patients with renal insufficiency. (5.13)
• Serious, acute hypersensitivity reactions and cutaneous eruptions. (5.14)
• Dental/periodontal disorders reported with combination therapy. (5.16)
• Hypertriglyceridemia may result in pancreatitis (e.g., triglycerides >1000 mg/dL). (5.17)
• Weight loss and growth inhibition reported with combination therapy in pediatric patients. (5.18)
• Peripheral neuropathy when used in combination with telbivudine. (5.19)

ADVERSE REACTIONS

Most common adverse reactions (>40%) in adult patients receiving either

PegIntron or PegIntron/REBETOL are injection site inflammation/

reaction, fatigue/asthenia, headache, rigors, fevers, nausea, myalgia and anxiety/emotional lability/irritability (6.1). Most common adverse reactions (>25%) in pediatric patients receiving PegIntron/REBETOL are pyrexia, headache, neutropenia, fatigue, anorexia, injection-site erythema, vomiting (6.1).

To report SUSPECTED ADVERSE REACTIONS, contact Schering Corporation, a subsidiary of Merck & Co., Inc., at 1-800-526-4099 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

DRUG INTERACTIONS

• Drug metabolized by CYP450: Caution with drugs metabolized by CYP2C8/9 (e.g., warfarin, phenytoin) or CYP2D6 (e.g., flecainide). (7.1)
• Methadone: Monitor for increased narcotic effect. (7.2)
• Nucleoside analogues: Closely monitor for toxicities. Discontinue nucleoside reverse transcriptase inhibitors or reduce dose or discontinue interferon, ribavirin, or both with worsening toxicities. (7.3)
• Didanosine: Concurrent use with REBETOL is not recommended. (7.3)

USE IN SPECIFIC POPULATIONS

• Ribavirin Pregnancy Registry: 1-800-593-2214 (8.1)
• Pediatrics: safety and efficacy in pediatrics <3 years old have not been established (8.4)
• Geriatrics: neuropsychiatric, cardiac, pulmonary, GI, and systemic (flu-like) adverse reactions may be more severe (8.5)
• Organ transplant: safety and efficacy have not been studied (8.6)
• HIV or HBV co-infection: safety and efficacy have not been established (8.7)

See 17 for PATIENT COUNSELING INFORMATION and Medication Guide.

Revised: 02/2011

FULL PRESCRIBING INFORMATION: CONTENTS*

WARNING – RISK OF SERIOUS DISORDERS AND RIBAVIRIN-ASSOCIATED EFFECTS

1 INDICATIONS AND USAGE

1.1 Chronic Hepatitis C

2 DOSAGE AND ADMINISTRATION

2.1 PegIntron/REBETOL Combination Therapy

2.2 PegIntron Monotherapy

2.3 Dose Reduction

2.4 Discontinuation of Dosing

2.5 Renal Function

2.6 Preparation and Administration

3 DOSAGE FORMS AND STRENGTHS

4 CONTRAINDICATIONS

5 WARNINGS AND PRECAUTIONS

5.1 Use with Ribavirin

5.2 Neuropsychiatric Events

5.3 Cardiovascular Events

5.4 Endocrine Disorders

5.5 Ophthalmologic Disorders

5.6 Cerebrovascular Disorders

5.7 Bone Marrow Toxicity

5.8 Autoimmune Disorders

5.9 Pancreatitis

5.10 Colitis

5.11 Pulmonary Disorders

5.12 Hepatic Failure

5.13 Patients with Renal Insufficiency

5.14 Hypersensitivity

5.15 Laboratory Tests

5.16 Dental and Periodontal Disorders

5.17 Triglycerides

5.18 Impact on Growth- Pediatric Use

5.19 Peripheral Neuropathy

6 ADVERSE REACTIONS

6.1 Clinical Trials Experience

6.2 Immunogenicity

6.3 Postmarketing Experience

7 DRUG INTERACTIONS

7.1 Drugs Metabolized by Cytochrome P-450

7.2 Methadone

7.3 Use with Ribavirin (Nucleoside Analogues)

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

8.3 Nursing Mothers

8.4 Pediatric Use

8.5 Geriatric Use

8.6 Organ Transplant Recipients

8.7 HIV or HBV Co-infection

10 OVERDOSAGE

11 DESCRIPTION

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

12.2 Pharmacodynamics

12.3 Pharmacokinetics

12.4 Microbiology

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

14 CLINICAL STUDIES

14.1 Chronic Hepatitis C in Adults

14.2 Chronic Hepatitis C in Pediatrics

16 HOW SUPPLIED/STORAGE AND HANDLING

17 PATIENT COUNSELING INFORMATION

17.1 Pregnancy

17.2 HCV Transmission

17.3 Laboratory Evaluations, Hydration, “Flu-like” Symptoms

17.4 Instructions for Use

*Sections or subsections omitted from the full prescribing information are not listed.

FULL PRESCRIBING INFORMATION

WARNING: RISK OF SERIOUS DISORDERS AND RIBAVIRIN-ASSOCIATED EFFECTS

Alpha interferons, including PegIntron, may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory evaluations. Patients with persistently severe or worsening signs or symptoms of these conditions should be withdrawn from therapy. In many, but not all cases, these disorders resolve after stopping PegIntron therapy [see Warnings and Precautions (5) and Adverse Reactions (6.1)].

Use with Ribavirin

Ribavirin may cause birth defects and death of the unborn child. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients. Ribavirin causes hemolytic anemia. The anemia associated with REBETOL therapy may result in a worsening of cardiac disease. Ribavirin is genotoxic and mutagenic and should be considered a potential carcinogen. [See REBETOL package insert]

1 INDICATIONS AND USAGE

1.1 Chronic Hepatitis C

Combination therapy:

PegIntron® in combination with REBETOL® (ribavirin) is indicated for the treatment of chronic hepatitis C in patients 3 years of age and older with compensated liver disease.

The following points should be considered when initiating therapy with PegIntron in combination with REBETOL:

• These indications are based on achieving undetectable HCV-RNA after treatment for 24 or 48 weeks and maintaining a Sustained Virologic Response (SVR) 24 weeks after the last dose.
• Patients with the following characteristics are less likely to benefit from retreatment after failing a course of therapy: previous nonresponse, previous pegylated interferon treatment, significant bridging fibrosis or cirrhosis, and genotype 1 infection [see Clinical Studies (14)].
• No safety and efficacy data are available for treatment of longer than 1 year.

Monotherapy (for patients who are intolerant to ribavirin):

PegIntron (peginterferon alfa-2b) is indicated for use alone for the treatment of chronic hepatitis C in patients with compensated liver disease previously untreated with interferon alpha and who are at least 18 years of age.

The following point should be considered when initiating therapy with PegIntron alone:

• Combination therapy with REBETOL is preferred over PegIntron monotherapy unless there are contraindications to or significant intolerance of REBETOL.

Combination therapy provides substantially better response rates than monotherapy [see Clinical Studies (14)].

2 DOSAGE AND ADMINISTRATION

2. 1 PegIntron/REBETOL Combination Therapy

REBETOL should be taken with food. REBETOL should not be used in patients with creatinine clearance <50 mL/min.

Adults

The recommended dose of PegIntron is 1.5 mcg/kg/week subcutaneously in combination with 800 to 1400 mg of REBETOL orally based on patient body weight. The volume of PegIntron to be injected depends on the strength of PegIntron and patient’s body weight (see Table 1).

Duration of Treatment – Interferon Alpha-naïve Patients

The treatment duration for patients with genotype 1 is 48 weeks. Discontinuation of therapy should be considered in patients who do not achieve at least a 2 log₁₀ drop or loss of HCV-RNA at 12 weeks, or if HCV-RNA remains detectable after 24 weeks of therapy. Patients with genotype 2 and 3 should be treated for 24 weeks.

Duration of Treatment – Re-treatment with PegIntron/REBETOL of Prior Treatment Failures

The treatment duration for patients who previously failed therapy is 48 weeks, regardless of HCV genotype. Re-treated patients who fail to achieve undetectable HCV-RNA at Week 12 of therapy, or whose HCV-RNA remains detectable after 24 weeks of therapy, are highly unlikely to achieve SVR and discontinuation of therapy should be considered [see Clinical Studies (14.1)].

TABLE 1 Recommended PegIntron Combination Therapy Dosing (Adults)
Body weight kg (lbs)	PegIntron REDIPEN^® or Vial Strength to Use	Amount of PegIntron (mcg) to Administer	Volume (mL)* of PegIntron to Administer	REBETOL Daily Dose	REBETOL Number of Capsules
<40 (<88)	50 mcg per 0.5 mL	50	0.5	800 mg/day	2 x 200 mg capsules A.M. 2 x 200 mg capsules P.M.
40 – 50 (88 – 111)	80 mcg per 0.5 mL	64	0.4	800 mg/day	2 x 200 mg capsules A.M. 2 x 200 mg capsules P.M.
51 – 60 (112 – 133)		80	0.5	800 mg/day	2 x 200 mg capsules A.M. 2 x 200 mg capsules P.M.
61 – 65 (134 – 144)	120 mcg per 0.5 mL	96	0.4	800 mg/day	2 x 200 mg capsules A.M. 2 x 200 mg capsules P.M.
66 – 75 (145 – 166)		96	0.4	1000 mg/day	2 x 200 mg capsules A.M. 3 x 200 mg capsules P.M.
76 – 80 (167 – 177)		120	0.5	1000 mg/day	2 x 200 mg capsules A.M. 3 x 200 mg capsules P.M.
81 – 85 (178 – 187)				1200 mg/day	3 x 200 mg capsules A.M. 3 x 200 mg capsules P.M.
86 – 105 (188 – 231)	150 mcg per 0.5 mL	150	0.5	1200 mg/day	3 x 200 mg capsules A.M. 3 x 200 mg capsules P.M.
>105 (>231)	**	**	**	1400 mg/day	3 x 200 mg capsules A.M. 4 x 200 mg capsules P.M.

* When reconstituted as directed.

** For patients weighing >105 kg (>231 pounds), the PegIntron dose of 1.5 mcg/kg/week should be calculated based on the individual patient weight. Two vials of PegIntron may be necessary to provide the dose.

Pediatric Patients

Dosing for pediatric patients is determined by body surface area for PegIntron and by body weight for REBETOL. The recommended dose of PegIntron is 60mcg/m²/week subcutaneously in combination with 15 mg/kg/day of REBETOL orally in 2 divided doses (see Table 2) for pediatric patients ages 3 to 17 years. Patients who reach their 18th birthday while receiving PegIntron/REBETOL, should remain on the pediatric dosing regimen. The treatment duration for patients with genotype 1 is 48 weeks. Patients with genotype 2 and 3 should be treated for 24 weeks.

TABLE 2 Recommended REBETOL^* Dosing in Combination Therapy (Pediatrics)
Body weight kg (lbs)	REBETOL Daily Dose	REBETOL Number of Capsules
<47 (<103)	15 mg/kg/day	Use REBETOL Oral Solution^**
47 – 59 (103-131)	800 mg/day	2 x 200 mg capsules A.M. 2 x 200 mg capsules P.M.
60 – 73 (132-162)	1000 mg/day	2 x 200 mg capsules A.M. 3 x 200 mg capsules P.M.
>73 (>162)	1200 mg/day	3 x 200 mg capsules A.M. 3 x 200 mg capsules P.M.

^*REBETOL to be used in combination with PegIntron 60 mcg/m² weekly.

^** REBETOL Oral Solution may be used for any patient regardless of body weight.

2.2 PegIntron Monotherapy

The recommended dose of PegIntron regimen is 1 mcg/kg/week subcutaneously for 1 year administered on the same day of the week. Discontinuation of therapy should be considered in patients who do not achieve at least a 2 log₁₀ drop or loss of HCV-RNA at 12 weeks of therapy, or whose HCV-RNA levels remain detectable after 24 weeks of therapy. The volume of PegIntron to be injected depends on patient weight (see Table 3).

TABLE 3 Recommended PegIntron Monotherapy Dosing
Body weight kg (lbs)	PegIntron REDIPEN or Vial Strength to Use	Amount of PegIntron (mcg) to Administer	Volume (mL)^*of PegIntron to Administer
≤45 (≤100)	50 mcg per 0.5 mL	40	0.4
46 – 56 (101 – 124)		50	0.5
57 – 72 (125 – 159)	80 mcg per 0.5 mL	64	0.4
73 – 88 (160 – 195)		80	0.5
89 – 106 (196 – 234)	120 mcg per 0.5 mL	96	0.4
107 – 136 (235 – 300)		120	0.5
137 – 160 (301 – 353)	150 mcg per 0.5 mL	150	0.5

* When reconstituted as directed.

2.3 Dose Reduction

If a serious adverse reaction develops during the course of treatment [see Warnings and Precautions (5)] discontinue or modify the dosage of PegIntron and REBETOL until the adverse event abates or decreases in severity. If persistent or recurrent serious adverse events develop despite adequate dosage adjustment, discontinue treatment. For guidelines for dose modifications and discontinuation based on depression or laboratory parameters, see Tables 4 and 5. Dose reduction of PegIntron in adult patients on PegIntron/REBETOL combination therapy is accomplished in a two-step process from the original starting dose of 1.5 mcg/kg/week, to 1 mcg/kg/week, then to 0.5 mcg/kg/week, if needed. Dose reduction in patients on PegIntron monotherapy is accomplished by reducing the original starting dose of 1 mcg/kg/week to 0.5 mcg/kg/week. Dose reduction of PegIntron in adults may be accomplished by utilizing a lower dose strength or administering a lesser volume as shown in Table 6 or 7.

In the adult combination therapy Study 2, dose reductions occurred in 42% of subjects receiving PegIntron 1.5 mcg/kg plus REBETOL 800 mg daily, including 57% of those subjects weighing 60 kg or less. In Study 4, 16% of subjects had a dose reduction of PegIntron to 1 mcg/kg in combination with REBETOL, with an additional 4% requiring the second dose reduction of PegIntron to 0.5 mcg/kg due to adverse events [see Adverse Reactions (6.1)].

Dose reduction in pediatric patients is accomplished by modifying the recommended dose in a 2-step process from the original starting dose of 60 mcg/m²/week, to 40 mcg/m²/week, then to 20 mcg/m²/week, if needed (see Tables 4 and 5). In the pediatric combination therapy trial, dose reductions occurred in 25% of subjects receiving PegIntron 60 mcg/m² weekly plus REBETOL 15 mg/kg daily.

TABLE 4 Guidelines for Modification or Discontinuation of PegIntron or PegIntron/REBETOL and for Scheduling Visits for Patients with Depression
Depression Severity^*	Initial Management (4-8 weeks)		Depression Status
	Dose Modification	Visit Schedule	Remains Stable	Improves	Worsens
Mild	No change	Evaluate once weekly by visit or phone.	Continue weekly visit schedule.	Resume normal visit schedule.	See moderate or severe depression
Moderate	Adults: Adjust Dose* Pediatrics: Decrease dose to 40 mcg/m^2/week, then to 20 mcg/m^2/week, if needed	Evaluate once weekly (office visit at least every other week).	Consider psychiatric consultation. Continue reduced dosing.	If symptoms improve and are stable for 4 weeks, may resume normal visit schedule. Continue reduced dosing or return to normal dose.	See severe depression
Severe	Discontinue PegIntron/REBETOL permanently.	Obtain immediate psychiatric consultation.	Psychiatric therapy as necessary

^* See DSM-IV for definitions. For patients on PegIntron/REBETOL combination therapy: 1^st dose reduction of PegIntron is to 1 mcg/kg/week, 2^nd dose reduction (if needed) of PegIntron is to 0.5 mcg/kg/week. For patients on PegIntron monotherapy: decrease PegIntron dose to 0.5 mcg/kg/week.

TABLE 5 Guidelines for Dose Modification and Discontinuation of PegIntron or PegIntron/REBETOL Based on Laboratory Parameters in Adults and Pediatrics
Laboratory Values	PegIntron		REBETOL
	Adults	Pediatrics	Adults	Pediatrics
Hgb < 10g/dL	For patients with cardiac disease, reduce by 50%*	See footnote*	Adjust Dose**	1^st reduction to 12mg/kg/day 2^nd reduction to 8mg/kg/day
WBC < 1.5 x 10^9/L   Neutrophils < 0.75 x 10^9/L   Platelets < 50 x 10^9/L (Adults) < 70 x 10^9/L (Pediatrics)	Adjust Dose***	1^st reduction to 40mcg/m^2/week 2^nd reduction to 20mcg/m^2/week	No Dose Change	No Dose Change
Hgb < 8.5g/dL   WBC < 1 x 10^9/L   Neutrophils < 0.5 x 10^9/L Platelets <25 x 10^9/L (Adults) < 50 x 10^9/L (Pediatrics)   Creatinine > 2 mg/dL (Pediatrics)	Permanently Discontinue	Permanently Discontinue	Permanently Discontinue	Permanently Discontinue

* For adult patients with a history of stable cardiac disease receiving PegIntron in combination with ribavirin, the PegIntron dose should be reduced by half and the ribavirin dose by 200 mg/day if a >2 g/dL decrease in hemoglobin is observed during any 4-week period. Both PegIntron and ribavirin should be permanently discontinued if patients have hemoglobin levels <12 g/dL after this ribavirin dose reduction. Pediatric patients who have pre-existing cardiac conditions and experience a hemoglobin decrease ≥2 g/dL during any 4-week period during treatment should have weekly evaluations and hematology testing.

** 1^st dose reduction of REBETOL is by 200 mg/day, except in patients receiving the 1400 mg dose it is by 400 mg/day; 2^nd dose reduction of REBETOL (if needed) is by an additional 200 mg/day.

*** For patients on PegIntron/REBETOL combination therapy: 1^st dose reduction of PegIntron is to 1 mcg/kg/week, 2^nd dose reduction (if needed) of PegIntron is to 0.5 mcg/kg/week. For patients on PegIntron monotherapy: decrease PegIntron dose to 0.5 mcg/kg/week.

TABLE 6 Reduced PegIntron Dose (0.5 mcg/kg) for (1 mcg/kg) Monotherapy in Adults
Body weight kg(lbs)	PegIntron REDIPEN/Vial Strength to Use	Amount of PegIntron (mcg) to Administer	Volume (mL)**of PegIntron to Administer
≤45 (≤100)	50 mcg per 0.5 mL*	20	0.2
46 – 56 (101 – 124)		25	0.25
57 – 72 (125 – 159)	50 mcg per 0.5 mL	30	0.3
73 – 88 (160 – 195)		40	0.4
89 – 106 (196 – 234)	50 mcg per 0.5 mL	50	0.5
107 – 136 (235 – 300)	80 mcg per 0.5 mL	64	0.4
≥137 (≥301)		80	0.5

* Must use vial. Minimum delivery for REDIPEN 0.3 mL.

** When reconstituted as directed.

TABLE 7 Two-Step Dose Reduction of PegIntron in Combination Therapy in Adults
First Dose Reduction to PegIntron 1 mcg/kg				Second Dose Reduction to PegIntron 0.5 mcg/kg
Body weight kg(lbs)	PegIntron REDIPEN/Vial Strength to Use	Amount of PegIntron (mcg) to Administer	Volume (mL) **of PegIntron to Administer	Body weight kg(lbs)	PegIntron REDIPEN/Vial Strength to Use	Amount of PegIntron (mcg) to Administer	Volume (mL)** of PegIntron to Administer
<40 (<88)	50 mcg per 0.5 mL	35	0.35	<40 (<88)	50 mcg per 0.5 mL*	20	0.2
40 – 50 (88 – 111)		45	0.45	40 – 50 (88 – 111)		25	0.25
51 – 60 (112 – 133)		50	0.5	51 – 60 (112 – 133)	50 mcg per 0.5 mL	30	0.3
61 – 75 (134 – 166)	80 mcg per 0.5 mL	64	0.4	61 – 75 (134 –166)		35	0.35
76 – 85 (167 – 187)		80	0.5	76 – 85 (167 – 187)		45	0.45
86-104 (188-230)	120 mcg per 0.5 mL	96	0.4	86-104 (188-230)		50	0.5
105-125 (231-275)		108	0.45	105-125 (231-275)	80 mcg per 0.5 mL	64	0.4
>125 (>275)	150 mcg per 0.5 mL	135	0.45	>125 (>275)		72	0.45

* Must use vial. Minimum delivery for REDIPEN 0.3 mL.

** When reconstituted as directed.

2.4 Discontinuation of Dosing

Adults

It is recommended that HCV genotype 1 interferon-alfa-naïve patients receiving PegIntron, alone or in combination with ribavirin, be discontinued from therapy if there is not at least a 2 log₁₀ drop or loss of HCV-RNA at 12 weeks of therapy, or whose HCV-RNA levels remain detectable after 24 weeks of therapy. Regardless of genotype, previously treated patients who have detectable HCV-RNA at Week 12 or 24, are highly unlikely to achieve SVR and discontinuation of therapy should be considered.

Pediatrics (3-17 years of age)

It is recommended that patients receiving PegIntron/REBETOL combination (excluding those with HCV Genotype 2 and 3) be discontinued from therapy at 12 weeks if their treatment Week 12 HCV-RNA dropped <2 log₁₀ compared to pretreatment or at 24 weeks if they have detectable HCV-RNA at treatment Week 24.

2.5 Renal Function

In patients with moderate renal dysfunction (creatinine clearance 30-50 mL/min), the PegIntron dose should be reduced by 25%. Patients with severe renal dysfunction (creatinine clearance 10-29 mL/min), including those on hemodialysis, should have the PegIntron dose reduced by 50%. If renal function decreases during treatment, PegIntron therapy should be discontinued. When PegIntron is administered in combination with REBETOL, subjects with impaired renal function or those over the age of 50 should be more carefully monitored with respect to the development of anemia. PegIntron/REBETOL should not be used in patients with creatinine clearance <50 mL/min.

2.6 Preparation and Administration

PegIntron REDIPEN

PegIntron REDIPEN consists of a dual-chamber glass cartridge with sterile, lyophilized peginterferon alfa-2b in the active chamber and Sterile Water for Injection USP in the diluent chamber. The PegIntron in the glass cartridge should appear as a white to off-white tablet-shaped solid that is whole or in pieces, or powder.

To reconstitute the lyophilized peginterferon alfa-2b in the REDIPEN:

• Hold the REDIPEN upright (dose button down) and press the 2 halves of the pen together until there is an audible click.
• Gently invert the pen to mix the solution. DO NOT SHAKE. The reconstituted solution has a concentration of either 50 mcg per 0.5 mL, 80 mcg per 0.5 mL, 120 mcg per 0.5 mL, or 150 mcg per 0.5 mL for a single subcutaneous injection.
• Visually inspect the solution for particulate matter and discoloration prior to administration. The reconstituted solution should be clear and colorless. Do not use the solution if it is discolored or not clear, or if particulates are present.

Keeping the pen upright, attach the supplied needle and select the appropriate PegIntron dose by pulling back on the dosing button until the dark bands are visible and turning the button until the dark band is aligned with the correct dose. The prepared PegIntron solution is to be injected subcutaneously.

The PegIntron REDIPEN is a single-use pen and does not contain a preservative. The reconstituted solution should be used immediately and cannot be stored for more than 24 hours at 2^°-8^° C [see How Supplied/Storage and Handling (16)]. DO NOT REUSE THE REDIPEN. The sterility of any remaining product can no longer be guaranteed. DISCARD THE UNUSED PORTION. Pooling of unused portions of some medications has been linked to bacterial contamination and morbidity.

PegIntron Vials

Two BD® Safety-Lok^® syringes are provided in the package; one syringe is for the reconstitution steps and one for the patient injection. There is a plastic safety sleeve to be pulled over the needle after use. The syringe locks with an audible click when the green stripe on the safety sleeve covers the red stripe on the needle. Instructions for the preparation and administration of PegIntron Powder for Injection are provided below.

• Reconstitute the PegIntron lyophilized product with only 0.7 mL of the 1.25 mL of supplied diluent (Sterile Water for Injection USP). The diluent vial is for single use only. The remaining diluent should be discarded. No other medications should be added to solutions containing PegIntron, and
  PegIntron should not be reconstituted with other diluents.
• Swirl gently to hasten complete dissolution of the powder. The reconstituted solution should be clear and colorless.
• Visually inspect the solution for particulate matter and discoloration prior to administration. The solution should not be used if discolored or cloudy, or if particulates are present.
• The appropriate PegIntron dose should be withdrawn and injected subcutaneously. PegIntron vials are for single use only and do not contain a preservative.

The reconstituted solution should be used immediately and cannot be stored for more than 24 hours at 2°-8° C [see How Supplied/Storage and Handling (16)]. DO NOT REUSE THE VIAL. The sterility of any remaining product can no longer be guaranteed. DISCARD THE UNUSED PORTION. Pooling of unused portions of some medications has been linked to bacterial contamination and morbidity.

3 DOSAGE FORMS AND STRENGTHS

• Single-use vial: 1.25 mL diluent vial: 50 mcg per 0.5 mL, 80 mcg per 0.5 mL, 120 mcg per 0.5 mL, 150 mcg per 0.5 mL.
• Single-use REDIPEN: 50 mcg per 0.5 mL, 80 mcg per 0.5 mL, 120 mcg per 0.5 mL, 150 mcg per 0.5 mL.

4 CONTRAINDICATIONS

PegIntron is contraindicated in patients with:

• known hypersensitivity reactions, such as urticaria, angioedema, bronchoconstriction, anaphylaxis, Stevens-Johnson syndrome, and toxic epidermal necrolysis to interferon alpha or any other component of the product
• autoimmune hepatitis
• hepatic decompensation (Child-Pugh score >6 [class B and C]) in cirrhotic CHC patients before or during treatment

PegIntron /REBETOL combination therapy is additionally contraindicated in:

• women who are pregnant. REBETOL may cause fetal harm when administered to a pregnant woman. REBETOL is contraindicated in women who are or may become pregnant. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug the patient should be apprised of the potential hazard to a fetus [see Use in Specific Populations (8.1)].
• men whose female partners are pregnant
• patients with hemoglobinopathies (e.g., thalassemia major, sickle-cell anemia)
• patients with creatinine clearance <50 mL/min

5 WARNINGS AND PRECAUTIONS

Patients should be monitored for the following serious conditions, some of which may become life threatening. Patients with persistently severe or worsening signs or symptoms should be withdrawn from therapy.

5.1 Use with Ribavirin

Pregnancy

REBETOL may cause birth defects and death of the unborn child. REBETOL therapy should not be started until a report of a negative pregnancy test has been obtained immediately prior to planned initiation of therapy. Patients should use at least 2 forms of contraception and have monthly pregnancy tests [see BOXED WARNING, Contraindications (4), Patient Counseling Information (17), and REBETOL package insert].

Anemia

Ribavirin caused hemolytic anemia in 10% of PegIntron/REBETOL-treated subjects within 1 to 4 weeks of initiation of therapy. Complete blood counts should be obtained pretreatment and at Week 2 and Week 4 of therapy or more frequently if clinically indicated. Anemia associated with REBETOL therapy may result in a worsening of cardiac disease. Decrease in dosage or discontinuation of REBETOL may be necessary [see Dosage and Administration (2.3) and REBETOL package insert].

5.2 Neuropsychiatric Events

Life-threatening or fatal neuropsychiatric events, including suicide, suicidal and homicidal ideation, depression, relapse of drug addiction/overdose, and aggressive behavior sometimes directed towards others have occurred in patients with and without a previous psychiatric disorder during PegIntron treatment and follow-up. Psychoses, hallucinations, bipolar disorders, and mania have been observed in patients treated with interferon alpha. PegIntron should be used with extreme caution in patients with a history of psychiatric disorders. Patients should be advised to report immediately any symptoms of depression or suicidal ideation to their prescribing physicians. Physicians should monitor all patients for evidence of depression and other psychiatric symptoms. If patients develop psychiatric problems, including clinical depression, it is recommended that the patients be carefully monitored during treatment and in the 6-month follow-up period. If psychiatric symptoms persist or worsen, or suicidal ideation or aggressive behavior towards others is identified, it is recommended that treatment with PegIntron be discontinued, and the patient followed, with psychiatric intervention as appropriate. In severe cases, PegIntron should be stopped immediately and psychiatric intervention instituted [see Dosage and Administration (2.3)]. Cases of encephalopathy have been observed in some patients, usually elderly, treated at higher doses of PegIntron.

5.3 Cardiovascular Events

Cardiovascular events, which include hypotension, arrhythmia, tachycardia, cardiomyopathy, angina pectoris, and myocardial infarction, have been observed in patients treated with PegIntron. PegIntron should be used cautiously in patients with cardiovascular disease. Patients with a history of myocardial infarction and arrhythmic disorder who require PegIntron therapy should be closely monitored [see Warnings and Precautions (5.15)]. Patients with a history of significant or unstable cardiac disease should not be treated with PegIntron /REBETOL combination therapy [see REBETOL package insert].

5.4 Endocrine Disorders

PegIntron causes or aggravates hypothyroidism and hyperthyroidism. Hyperglycemia has been observed in patients treated with PegIntron. Diabetes mellitus, including cases of new onset Type 1 diabetes, has been observed in patients treated with alpha interferons, including PegIntron. Patients with these conditions who cannot be effectively treated by medication should not begin PegIntron therapy. Patients who develop these conditions during treatment and cannot be controlled with medication should not continue PegIntron therapy.

5.5 Ophthalmologic Disorders

Decrease or loss of vision, retinopathy including macular edema, retinal artery or vein thrombosis, retinal hemorrhages and cotton wool spots, optic neuritis, papilledema, and serous retinal detachment may be induced or aggravated by treatment with peginterferon alfa-2b or other alpha interferons. All patients should receive an eye examination at baseline. Patients with preexisting ophthalmologic disorders (e.g., diabetic or hypertensive retinopathy) should receive periodic ophthalmologic exams during interferon alpha treatment. Any patient who develops ocular symptoms should receive a prompt and complete eye examination. Peginterferon alfa-2b treatment should be discontinued in patients who develop new or worsening ophthalmologic disorders.

5.6 Cerebrovascular Disorders

Ischemic and hemorrhagic cerebrovascular events have been observed in patients treated with interferon alfa-based therapies, including PegIntron. Events occurred in patients with few or no reported risk factors for stroke, including patients less than 45 years of age. Because these are spontaneous reports, estimates of frequency cannot be made, and a causal relationship between interferon alfa-based therapies and these events is difficult to establish.

5.7 Bone Marrow Toxicity

PegIntron suppresses bone marrow function, sometimes resulting in severe cytopenias. PegIntron should be discontinued in patients who develop severe decreases in neutrophil or platelet counts [see Dosage and Administration (2.3)]. Ribavirin may potentiate the neutropenia induced by interferon alpha. Very rarely alpha interferons may be associated with aplastic anemia.

5.8 Autoimmune Disorders

Development or exacerbation of autoimmune disorders (e.g., thyroiditis, thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura, rheumatoid arthritis, interstitial nephritis, systemic lupus erythematosus, and psoriasis) have been observed in patients receiving PegIntron.

PegIntron should be used with caution in patients with autoimmune disorders.

5.9 Pancreatitis

Fatal and nonfatal pancreatitis have been observed in patients treated with alpha interferon. PegIntron therapy should be suspended in patients with signs and symptoms suggestive of pancreatitis and discontinued in patients diagnosed with pancreatitis.

5.10 Colitis

Fatal and nonfatal ulcerative or hemorrhagic/ischemic colitis have been observed within 12 weeks of the start of alpha interferon treatment. Abdominal pain, bloody diarrhea, and fever are the typical manifestations. PegIntron treatment should be discontinued immediately in patients who develop these signs and symptoms. The colitis usually resolves within 1 to 3 weeks of discontinuation of alpha interferons.

5.11 Pulmonary Disorders

Dyspnea, pulmonary infiltrates, pneumonia, bronchiolitis obliterans, interstitial pneumonitis, pulmonary hypertension, and sarcoidosis, some resulting in respiratory failure or patient deaths, may be induced or aggravated by PegIntron or alpha interferon therapy. Recurrence of respiratory failure has been observed with interferon rechallenge. PegIntron combination treatment should be suspended in patients who develop pulmonary infiltrates or pulmonary function impairment. Patients who resume interferon treatment should be closely monitored.

Because of the fever and other "flu-like" symptoms associated with PegIntron administration, it should be used cautiously in patients with debilitating medical conditions, such as those with a history of pulmonary disease (e.g., chronic obstructive pulmonary disease).

5.12 Hepatic Failure

Chronic hepatitis C (CHC) patients with cirrhosis may be at risk of hepatic decompensation and death when treated with alpha interferons, including PegIntron. Cirrhotic CHC patients coinfected with HIV receiving highly active antiretroviral therapy (HAART) and alpha interferons with or without ribavirin appear to be at increased risk for the development of hepatic decompensation compared to patients not receiving HAART. During treatment, patients’ clinical status and hepatic function should be closely monitored, and PegIntron treatment should be immediately discontinued if decompensation (Child-Pugh score >6) is observed [see Contraindications (4)].

5.13 Patients with Renal Insufficiency

Increases in serum creatinine levels have been observed in patients with renal insufficiency receiving interferon alpha products, including PegIntron. Patients with impaired renal function should be closely monitored for signs and symptoms of interferon toxicity, including increases in serum creatinine, and PegIntron dosing should be adjusted accordingly or discontinued [see Clinical Pharmacology (12.3) and Dosage and Administration (2.3)]. PegIntron monotherapy should be used with caution in patients with creatinine clearance <50 mL/min; the potential risks should be weighed against the potential benefits in these patients. Combination therapy with REBETOL must not be used in patients with creatinine clearance <50 mL/min [see REBETOL Package Insert].

5.14 Hypersensitivity

Serious, acute hypersensitivity reactions (e.g., urticaria, angioedema, bronchoconstriction, anaphylaxis) and cutaneous eruptions (Stevens-Johnson syndrome, toxic epidermal necrolysis) have been rarely observed during alpha interferon therapy. If such a reaction develops during treatment with PegIntron, discontinue treatment and institute appropriate medical therapy immediately. Transient rashes do not necessitate interruption of treatment.

5.15 Laboratory Tests

PegIntron alone or in combination with ribavirin may cause severe decreases in neutrophil and platelet counts, and hematologic, endocrine (e.g., TSH), and hepatic abnormalities. Transient elevations in ALT (2- to 5-fold above baseline) were observed in 10% of subjects treated with PegIntron, and were not associated with deterioration of other liver functions. Triglyceride levels are frequently elevated in patients receiving alpha interferon therapy including PegIntron and should be periodically monitored.

Patients on PegIntron or PegIntron/REBETOL combination therapy should have hematology and blood chemistry testing before the start of treatment and then periodically thereafter. In the adult clinical trial CBC (including hemoglobin, neutrophil, and platelet counts) and chemistries (including AST, ALT, bilirubin, and uric acid) were measured during the treatment period at Weeks 2, 4, 8, and 12, and then at 6-week intervals or more frequently if abnormalities developed. In pediatric subjects, the same laboratory parameters were evaluated with additional assessment of hemoglobin at treatment Week 6. TSH levels were measured every 12 weeks during the treatment period. HCV-RNA should be measured periodically during treatment [see Dosage and Administration (2)].

Patients who have pre-existing cardiac abnormalities should have electrocardiograms done before treatment with PegIntron/REBETOL.

5.16 Dental and Periodontal Disorders

Dental and periodontal disorders have been reported in patients receiving PegIntron/REBETOL combination therapy. In addition, dry mouth could have a damaging effect on teeth and mucous membranes of the mouth during long-term treatment with the combination of REBETOL and PegIntron. Patients should brush their teeth thoroughly twice daily and have regular dental examinations. If vomiting occurs, patients should be advised to rinse out their mouth thoroughly afterwards.

5.17 Triglycerides

Elevated triglyceride levels have been observed in patients treated with interferon alpha, including PegIntron therapy. Hypertriglyceridemia may result in pancreatitis [see Warnings and Precautions (5.9)]. Elevated triglyceride levels should be managed as clinically appropriate. Discontinuation of PegIntron therapy should be considered for patients with symptoms of potential pancreatitis, such as abdominal pain, nausea, or vomiting, and persistently elevated triglycerides (e.g., triglycerides >1000 mg/dL).

5.18 Impact on Growth-Pediatric Use

Data on the effects of PegIntron plus REBETOL on growth come from an open-label study in subjects 3 through 17 years of age, and weight and height changes are compared to US normative population data. In general, the weight and height gain of pediatric subjects treated with PegIntron plus REBETOL lags behind that predicted by normative population data for the entire length of treatment. After about 6 months post-treatment (follow-up Week 24), subjects had weight gain rebounds and regained their weight to 53^rd percentile, above the average of the normative population and similar to that predicted by their average baseline weight (57^th percentile). After about 6 months post-treatment, height gain stabilized and subjects treated with PegIntron plus REBETOL had an average height percentile of 44^th percentile, which was less than the average of the normative population and less than their average baseline height (51^st percentile). Severely inhibited growth velocity (< 3^rd percentile) was observed in 70% of the subjects while on treatment. Of the subjects experiencing severely inhibited growth, 20% had continued inhibited growth velocity (< 3^rd percentile) after 6 months of follow-up.

Among the boys studied, the age groups of 3 to 11 years old and 12 to 17 years old had similar height percentile decreases of approximately 5 percentiles after 6 months post-treatment; weight gain continued to be similar to their average baseline percentile. Girls who were 3 to 11 years old and treated for 48 weeks had the largest average drop in height and weight percentiles (13 percentiles and 7 percentiles, respectively), whereas girls 12 to 17 years old continued along their average baseline height and weight percentiles after 6 months post-treatment.

5.19 Peripheral Neuropathy

Peripheral neuropathy has been reported when alpha interferons were given in combination with telbivudine. In one clinical trial, an increased risk and severity of peripheral neuropathy was observed with the combination use of telbivudine and pegylated interferon alfa-2a as compared to telbivudine alone. The safety and efficacy of telbivudine in combination with interferons for the treatment of chronic hepatitis B has not been demonstrated.

6 ADVERSE REACTIONS

Clinical trials with PegIntron alone or in combination with REBETOL have been conducted in over 6900 subjects from 3 to 75 years of age.

Serious adverse reactions have occurred in approximately 12% of subjects in clinical trials with PegIntron with or without REBETOL [see BOXED WARNING, Warnings and Precautions (5)]. The most common serious events occurring in subjects treated with PegIntron and REBETOL were depression and suicidal ideation [see Warnings and Precautions (5.2)], each occurring at a frequency of less than 1%. The most common fatal events occurring in subjects treated with PegIntron and REBETOL were cardiac arrest, suicidal ideation, and suicide attempt [see Warnings and Precautions (5.2, 5.5)], all occurring in less than 1% of subjects.

Greater than 96% of all subjects in clinical trials experienced one or more adverse events. The most commonly reported adverse reactions in adult subjects receiving either PegIntron or PegIntron/REBETOL were injection-site inflammation/reaction, fatigue/asthenia, headache, rigors, fevers, nausea, myalgia, and emotional lability/irritability. The most common adverse events in pediatric subjects, ages 3 and older, were pyrexia, headache, vomiting, neutropenia, fatigue, anorexia, injection-site erythema, and abdominal pain.

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Adults

Study 1 compared PegIntron monotherapy with INTRON® A monotherapy. Study 2 compared combination therapy of PegIntron/REBETOL with combination therapy with INTRON A/REBETOL. In these studies, nearly all study subjects in clinical trials experienced one or more adverse reactions. Study 3 compared a PegIntron/weight-based REBETOL combination to a PegIntron/flat dose REBETOL regimen. Study 4 compared 2 PegIntron (1.5 mcg/kg/week and 1 mcg/kg/week) doses in combination with REBETOL and a third treatment group receiving Pegasys^® (180 mcg/week)/Copegus^® (1000-1200 mg/day).

Adverse reactions that occurred in Studies 1 and 2 at >5% incidence are provided in Table 8 by treatment group. Due to potential differences in ascertainment procedures, adverse reaction rate comparisons across studies should not be made. Table 9 summarizes the treatment-related/treatment emergent adverse reactions in Study 4 that occurred at a ≥10% incidence.

TABLE 8 Adverse Reactions Occurring in > 5% of Subjects
	Percentage of Subjects Reporting Adverse Reactions*
	Study 1		Study 2
Adverse Reactions	PegIntron 1 mcg/kg   (n=297)	INTRON A 3 MIU   (n=303)	PegIntron 1.5 mcg/kg/ REBETOL (n=511)	INTRON A/ REBETOL   (n=505)
Application Site
Injection Site Inflammation/Reaction	47	20	75	49
Autonomic Nervous System
Dry Mouth	6	7	12	8
Increased Sweating	6	7	11	7
Flushing	6	3	4	3
Body as a Whole
Fatigue/Asthenia	52	54	66	63
Headache	56	52	62	58
Rigors	23	19	48	41
Fever	22	12	46	33
Weight Loss	11	13	29	20
Right Upper Quadrant Pain	8	8	12	6
Chest Pain	6	4	8	7
Malaise	7	6	4	6
Central/Peripheral Nervous System
Dizziness	12	10	21	17
Endocrine
Hypothyroidism	5	3	5	4
Gastrointestinal
Nausea	26	20	43	33
Anorexia	20	17	32	27
Diarrhea	18	16	22	17
Vomiting	7	6	14	12
Abdominal Pain	15	11	13	13
Dyspepsia	6	7	9	8
Constipation	1	3	5	5
Hematologic Disorders
Neutropenia	6	2	26	14
Anemia	0	0	12	17
Leukopenia	<1	0	6	5
Thrombocytopenia	7	<1	5	2
Liver and Biliary System
Hepatomegaly	6	5	4	4
Musculoskeletal
Myalgia	54	53	56	50
Arthralgia	23	27	34	28
Musculoskeletal Pain	28	22	21	19
Psychiatric
Insomnia	23	23	40	41
Depression	29	25	31	34
Anxiety/Emotional Lability/Irritability	28	34	47	47
Concentration Impaired	10	8	17	21
Agitation	2	2	8	5
Nervousness	4	3	6	6
Reproductive, Female
Menstrual Disorder	4	3	7	6
Resistance Mechanism
Viral Infection	11	10	12	12
Fungal Infection	<1	3	6	1
Respiratory System
Dyspnea	4	2	26	24
Coughing	8	5	23	16
Pharyngitis	10	7	12	13
Rhinitis	2	2	8	6
Sinusitis	7	7	6	5
Skin and Appendages
Alopecia	22	22	36	32
Pruritus	12	8	29	28
Rash	6	7	24	23
Skin Dry	11	9	24	23
Special Senses, Other
Taste Perversion	<1	2	9	4
Vision Disorders
Vision Blurred	2	3	5	6
Conjunctivitis	4	2	4	5

*Subjects reporting one or more adverse reactions. A subject may have reported more than one adverse reaction within a body system/organ class category.

TABLE 9 Summary of Treatment-related/Treatment-emergent Adverse Reactions (≥10% Incidence) By Descending Frequency
	Percentage of Patients Reporting Treatment-related/Treatment- emergent Adverse Reactions
	Study 4
Adverse Reactions	PegIntron 1.5 mcg/kg with REBETOL   (n=1019)	PegIntron 1 mcg/kg with REBETOL   (n=1016)	Pegasys 180 mcg with Copegus     (n=1035)
Fatigue	67	68	64
Headache	50	47	41
Nausea	40	35	34
Chills	39	36	23
Insomnia	38	37	41
Anemia	35	30	34
Pyrexia	35	32	21
Injection Site Reactions	34	35	23
Anorexia	29	25	21
Rash	29	25	34
Myalgia	27	26	22
Neutropenia	26	19	31
Irritability	25	25	25
Depression	25	19	20
Alopecia	23	20	17
Dyspnea	21	20	22
Arthralgia	21	22	22
Pruritus	18	15	19
Influenza-like Illness	16	15	15
Dizziness	16	14	13
Diarrhea	15	16	14
Cough	15	16	17
Weight Decreased	13	10	10
Vomiting	12	10	9
Unspecified Pain	12	13	9
Dry Skin	11	11	12
Anxiety	11	11	10
Abdominal Pain	10	10	10
Leukopenia	9	7	10

The adverse reaction profile in Study 3, which compared PegIntron/weight-based REBETOL combination to a PegIntron/flat-dose REBETOL regimen, revealed an increased rate of anemia with weight-based dosing (29% vs. 19% for weight-based vs. flat-dose regimens, respectively). However, the majority of cases of anemia were mild and responded to dose reductions.

The incidence of serious adverse reactions was comparable in all studies. In the PEG monotherapy trial (Study 1) the incidence of serious adverse reactions was similar (about 12%) in all treatment groups. In Study 2, the incidence of serious adverse reactions was 17% in the PegIntron/REBETOL groups compared to 14% in the INTRON A/REBETOL group. In Study 3, there was a similar incidence of serious adverse reactions reported for the weight-based REBETOL group (12%) and with the flat-dose REBETOL regimen.

In many but not all cases, adverse reactions resolved after dose reduction or discontinuation of therapy. Some subjects experienced ongoing or new serious adverse reactions during the 6-month follow-up period.

There have been 31 subject deaths which occurred during treatment or during follow-up in these clinical trials. In Study 1, there was 1 suicide in a subject receiving PegIntron monotherapy and 2 deaths among subjects receiving INTRON A monotherapy (1 murder/suicide and 1 sudden death). In Study 2, there was 1 suicide in a subject receiving PegIntron/REBETOL combination therapy, and 1 subject death in the INTRON A/REBETOL group (motor vehicle accident). In Study 3, there were 14 deaths, 2 of which were probable suicides, and 1 was an unexplained death in a person with a relevant medical history of depression. In Study 4, there were 12 deaths, 6 of which occurred in subjects who received PegIntron/REBETOL combination therapy, 5 in the PegIntron 1.5 mcg/REBETOL arm (N=1019) and 1 in the PegIntron 1 mcg/REBETOL arm (N=1016), and 6 of which occurred in subjects receiving Pegasys/Copegus (N=1035). There were 3 suicides which occurred during the off-treatment follow-up period in subjects who received PegIntron (1.5 mcg/kg)/REBETOL combination therapy.

In Studies 1 and 2, 10% to 14% of subjects receiving PegIntron, alone or in combination with REBETOL, discontinued therapy compared with 6% treated with INTRON A alone and 13% treated with INTRON A in combination with REBETOL. Similarly in Study 3, 15% of subjects receiving PegIntron in combination with weight-based REBETOL and 14% of subjects receiving PegIntron and flat-dose REBETOL discontinued therapy due to an adverse reaction. The most common reasons for discontinuation of therapy were related to known interferon effects of psychiatric, systemic (e.g., fatigue, headache), or gastrointestinal adverse reactions. In Study 4, 13% of subjects in the PegIntron 1.5 mcg/REBETOL arm, 10% in the PegIntron 1 mcg/REBETOL arm, and 13% in the Pegasys 180 mcg/Copegus arm discontinued due to adverse events.

In Study 2, dose reductions due to adverse reactions occurred in 42% of subjects receiving PegIntron (1.5 mcg/kg)/REBETOL and in 34% of those receiving INTRON A/REBETOL. The majority of subjects (57%) weighing 60 kg or less receiving PegIntron (1.5 mcg/kg)/REBETOL required dose reduction. Reduction of interferon was dose-related (PegIntron 1.5 mcg/kg > PegIntron 0.5 mcg/kg or INTRON A), 40%, 27%, 28%, respectively. Dose reduction for REBETOL was similar across all 3 groups, 33% to 35%. The most common reasons for dose modifications were neutropenia (18%) or anemia (9%). Other common reasons included depression, fatigue, nausea, and thrombocytopenia. In Study 3, dose modifications due to adverse reactions occurred more frequently with WBD compared to flat dosing (29% and 23%, respectively). In Study 4, 16% of subjects had a dose reduction of PegIntron to 1 mcg/kg in combination with REBETOL, with an additional 4% requiring the second dose reduction of PegIntron to 0.5 mcg/kg due to adverse events, compared to 15% of subjects in the Pegasys/Copegus arm, who required a dose reduction to 135 mcg/week with Pegasys, with an additional 7% in the Pegasys/Copegus arm requiring a second dose reduction to 90 mcg/week with Pegasys.

In the PegIntron/REBETOL combination trials the most common adverse reactions were psychiatric which occurred among 77% of subjects in Study 2 and 68% to 69% of subjects in Study 3. These psychiatric adverse reactions included most commonly depression, irritability, and insomnia, each reported by approximately 30% to 40% of subjects in all treatment groups. Suicidal behavior (ideation, attempts, and suicides) occurred in 2% of all subjects during treatment or during follow-up after treatment cessation [see Warnings and Precautions (5.2)]. In Study 4, psychiatric adverse reactions occurred in 58 % of subjects in the PegIntron 1.5 mcg/REBETOL arm, 55% of subjects in the PegIntron 1 mcg/REBETOL arm, and 57% of subjects in the Pegasys 180 mcg/Copegus arm.

PegIntron induced fatigue or headache in approximately two-thirds of subjects, with fever or rigors in approximately half of the subjects. The severity of some of these systemic symptoms (e.g., fever and headache) tends to decrease as treatment continues. In Studies 1 and 2, application site inflammation and reaction (e.g., bruise, itchiness, and irritation) occurred at approximately twice the incidence with PegIntron therapies (in up to 75% of subjects) compared with INTRON A. However, injection-site pain was infrequent (2-3%) in all groups. In Study 3 there was a 23% to 24% incidence overall for injection-site reactions or inflammation.

In Study 2, many subjects continued to experience adverse reactions several months after discontinuation of therapy. By the end of the 6-month follow-up period, the incidence of ongoing adverse reactions by body class in the PegIntron 1.5/REBETOL group was 33% (psychiatric), 20% (musculoskeletal), and 10% (for endocrine and for GI). In approximately 10% to 15% of subjects, weight loss, fatigue, and headache had not resolved.

Individual serious adverse reactions in Study 2 occurred at a frequency ≤1% and included suicide attempt, suicidal ideation, severe depression; psychosis, aggressive reaction, relapse of drug addiction/overdose; nerve palsy (facial, oculomotor); cardiomyopathy, myocardial infarction, angina, pericardial effusion, retinal ischemia, retinal artery or vein thrombosis, blindness, decreased visual acuity, optic neuritis, transient ischemic attack, supraventricular arrhythmias, loss of consciousness; neutropenia, infection (sepsis, pneumonia, abscess, cellulitis); emphysema, bronchiolitis obliterans, pleural effusion, gastroenteritis, pancreatitis, gout, hyperglycemia, hyperthyroidism and hypothyroidism, autoimmune thrombocytopenia with or without purpura, rheumatoid arthritis, interstitial nephritis, lupus-like syndrome, sarcoidosis, aggravated psoriasis; urticaria, injection-site necrosis, vasculitis, and phototoxicity.

Subjects receiving PegIntron/REBETOL as re-treatment after failing a previous interferon combination regimen reported adverse reactions similar to those previously associated with this regimen during clinical trials of treatment-naïve subjects.

Pediatric Subjects

In general, the adverse-reaction profile in the pediatric population was similar to that observed in adults. In the pediatric study, the most prevalent adverse reactions in all subjects were pyrexia (80%), headache (62%), neutropenia (33%), fatigue (30%), anorexia (29%), injection-site erythema (29%), and vomiting (27%). The majority of adverse reactions reported in the study were mild or moderate in severity. Severe adverse reactions were reported in 7% (8/107) of all subjects and included injection-site pain (1%), pain in extremity (1%), headache (1%), neutropenia (1%), and pyrexia (4%). Important adverse reactions that occurred in this subject population were nervousness (7%; 7/107), aggression (3%; 3/107), anger (2%; 2/107), and depression (1%; 1/107). Five subjects received levothyroxine treatment; 3 with clinical hypothyroidism and 2 with asymptomatic TSH elevations.

Dose modifications were required in 25% of subjects, most commonly for anemia, neutropenia, and weight loss. Two subjects (2%; 2/107) discontinued therapy as the result of an adverse reaction.

Adverse reactions that occurred with a ≥10% incidence in the pediatric trial subjects are provided in Table10.

TABLE 10 Percentage of Pediatric Subjects With Treatment-emergent/Treatment-related Adverse Reactions (in at Least 10% of All Subjects)
System Organ Class Preferred Term	All Subjects n=107
Blood and Lymphatic System Disorders
Neutropenia	33%
Anemia	11%
Leukopenia	10%
Gastrointestinal Disorders
Abdominal Pain	21%
Abdominal Pain Upper	12%
Vomiting	27%
Nausea	18%
General Disorders and Administration Site Conditions
Pyrexia	80%
Fatigue	30%
Injection-site Erythema	29%
Chills	21%
Asthenia	15%
Irritability	14%
Investigations
Weight Decreased	19%
Metabolism and Nutrition Disorders
Anorexia	29%
Decreased Appetite	22%
Musculoskeletal and Connective Tissue Disorders
Arthralgia	17%
Myalgia	17%
Nervous System Disorders
Headache	62%
Dizziness	14%
Skin and Subcutaneous Tissue Disorders
Alopecia	17%

Laboratory Values

Adults

Changes in selected laboratory values during treatment with PegIntron alone or in combination with REBETOL treatment are described below. Decreases in hemoglobin, neutrophils, and platelets may require dose reduction or permanent discontinuation from therapy [see Dosage and Administration (2.3) and Warnings and Precautions (5.1, 5.7)].

Hemoglobin. Hemoglobin levels decreased to <11 g/dL in about 30% of subjects in Study 2. In Study 3, 47% of subjects receiving WBD REBETOL and 33% on flat-dose REBETOL had decreases in hemoglobin levels <11 g/dL. Reductions in hemoglobin to <9 g/dL occurred more frequently in subjects receiving WBD compared to flat dosing (4% and 2%, respectively). In Study 2, dose modification was required in 9% and 13% of subjects in the PegIntron/REBETOL and INTRON A/REBETOL groups. In Study 4, patients receiving PegIntron (1.5 mcg/kg)/REBETOL had decreases in hemoglobin levels to between 8.5 to <10 g/dL (28%) and to <8.5 g/dL (3%), whereas in patients receiving Pegasys 180 mcg/Copegus these decreases occurred in 26% and 4% of subjects, respectively. Hemoglobin levels become stable by treatment Weeks 4 to 6 on average. The typical pattern observed was a decrease in hemoglobin levels by treatment Week 4 followed by stabilization and a plateau, which was maintained to the end of treatment. In the PegIntron monotherapy trial, hemoglobin decreases were generally mild, and dose modifications were rarely necessary [see Dosage and Administration (2.3)].

Neutrophils. Decreases in neutrophil counts were observed in a majority of subjects treated with PegIntron alone (70%) or as combination therapy with REBETOL in Study 2 (85%) and INTRON A/REBETOL (60%). Severe potentially life-threatening neutropenia (<0.5 x 10⁹/L) occurred in 1% of subjects treated with PegIntron monotherapy, 2% of subjects treated with INTRON A/REBETOL, and in approximately 4% of subjects treated with PegIntron/REBETOL in Study 2. Two percent of subjects receiving PegIntron monotherapy and 18% of subjects receiving PegIntron/REBETOL in Study 2 required modification of interferon dosage. Few subjects (<1%) required permanent discontinuation of treatment. Neutrophil counts generally return to pretreatment levels 4 weeks after cessation of therapy [see Dosage and Administration (2.3)].

Platelets. Platelet counts decreased to <100,000/mm³ in approximately 20% of subjects treated with PegIntron alone or with REBETOL and in 6% of subjects treated with INTRON A/REBETOL. Severe decreases in platelet counts (<50,000/mm³) occur in <4% of subjects. Patients may require discontinuation or dose modification as a result of platelet decreases [see Dosage and Administration (2.3)]. In Study 2, 1% or 3% of subjects required dose modification of INTRON A or PegIntron, respectively. Platelet counts generally returned to pretreatment levels 4 weeks after the cessation of therapy.

Triglycerides. Elevated triglyceride levels have been observed in patients treated with interferon alphas, including PegIntron [see Warnings and Precautions (5.17)].

Thyroid Function. Development of TSH abnormalities, with and without clinical manifestations, are associated with interferon therapies. In Study 2, clinically apparent thyroid disorders occur among subjects treated with either INTRON A or PegIntron (with or without REBETOL) at a similar incidence (5% for hypothyroidism and 3% for hyperthyroidism). Subjects developed new-onset TSH abnormalities while on treatment and during the follow-up period. At the end of the follow-up period, 7% of subjects still had abnormal TSH values [see Warnings and Precautions (5.4)].

Bilirubin and Uric Acid. In Study 2, 10% to 14% of subjects developed hyperbilirubinemia and 33% to 38% developed hyperuricemia in association with hemolysis. Six subjects developed mild to moderate gout.

Pediatric Subjects

Decreases in hemoglobin, white blood cells, platelets, and neutrophils may require dose reduction or permanent discontinuation from therapy [see Dosage and Administration (2.3)]. Changes in selected laboratory values during treatment of 107 pediatric subjects with PegIntron/REBETOL combination therapy are described in Table 11. Most of the changes in laboratory values in this study were mild or moderate.

TABLE 11 Selected Hematological Abnormalities During Treatment Phase with PegIntron Plus REBETOL in Previously Untreated Pediatric Subjects
Laboratory Parameter^*	All Subjects (n=107)
Hemoglobin (g/dL)
9.5 – <11.0	30%
8.0 – <9.5	2%
WBC (x10^9/L)
2.0 – 2.9	39%
1.5 – <2.0	3%
Platelets (x10^9/L)
70 – 100	1%
50 – <70	-
25 – <50	1%
Neutrophils (x10^9/L)
1.0 – 1.5	35%
0.75 – <1.0	26%
0.5 – <0.75	13%
<0.5	3%
Total Bilirubin
1.26 - 2.59 xN^†	7%
Evidence of Hepatic Failure	-
* The table summarizes the worst category observed within the period per subject per laboratory test. Only subjects with at least one treatment value for a given laboratory test are included. ^†N=Upper limit of normal

6.2 Immunogenicity

As with all therapeutic proteins, there is potential for immunogenicity. Approximately 2% of subjects receiving PegIntron (32/1759) or INTRON A (11/728) with or without REBETOL developed low-titer (≤160) neutralizing antibodies to PegIntron or INTRON A. The clinical and pathological significance of the appearance of serum-neutralizing antibodies is unknown. The incidence of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors, including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to PegIntron with the incidence of antibodies to other products may be misleading.

6.3 Postmarketing Experience

The following adverse reactions have been identified during post-approval use of PegIntron therapy. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Blood and Lymphatic System Disorders

pure red cell aplasia, thrombotic thrombocytopenic purpura

Cardiac Disorders

palpitations

Ear and Labyrinth Disorders

hearing loss, vertigo, hearing impairment

Endocrine Disorders

diabetic ketoacidosis, diabetes

Eye Disorders

Vogt-Koyanagi-Harada syndrome, serous retinal detachment

Gastrointestinal Disorders

aphthous stomatitis

General Disorders and Administration Site Conditions

asthenic conditions (including asthenia, malaise, fatigue)

Immune System Disorders

cases of acute hypersensitivity reactions (including anaphylaxis, angioedema, urticaria); Stevens Johnson syndrome, toxic epidermal necrolysis, systemic lupus erythematosus, erythema multiforme

Infections and Infestations

bacterial infection including sepsis

Metabolism and Nutrition Disorders

dehydration, hypertriglyceridemia

Musculoskeletal and Connective Tissue Disorders

rhabdomyolysis, myositis

Nervous System Disorders

seizures, memory loss, peripheral neuropathy, paraesthesia, migraine headache

Psychiatric Disorders

homicidal ideation

Respiratory, Thoracic and Mediastinal Disorders

Pulmonary hypertension

Renal and Urinary Disorders

renal failure, renal insufficiency

Skin and Subcutaneous Tissue Disorders

psoriasis

Vascular Disorders

hypertension, hypotension

7 DRUG INTERACTIONS

7.1 Drugs Metabolized by Cytochrome P-450

When administering PegIntron with medications metabolized by CYP2C8/9 (e.g., warfarin and phenytoin) or CYP2D6 (e.g., flecainide), the therapeutic effect of these substrates may be decreased [see Clinical Pharmacology (12.3)].

7.2 Methadone

PegIntron may increase methadone concentrations [see Clinical Pharmacology (12.3)]. The clinical significance of this finding is unknown; however, patients should be monitored for the signs and symptoms of increased narcotic effect.

7.3 Use with Ribavirin (Nucleoside Analogues)

Hepatic decompensation (some fatal) has occurred in cirrhotic HIV/HCV co-infected patients receiving combination antiretroviral therapy for HIV and interferon alpha and ribavirin. Adding treatment with alpha interferons alone or in combination with ribavirin may increase the risk in this patient subset. Patients receiving interferon with ribavirin and nucleoside reverse transcriptase inhibitors (NRTIs) should be closely monitored for treatment- associated toxicities, especially hepatic decompensation and anemia. Discontinuation of NRTIs should be considered as medically appropriate [see Individual NRTI Product Information]. Dose reduction or discontinuation of interferon, ribavirin, or both should also be considered if worsening clinical toxicities are observed, including hepatic decompensation (e.g., Child-Pugh >6).

Stavudine, Lamivudine, and Zidovudine

In vitro studies have shown ribavirin can reduce the phosphorylation of pyrimidine nucleoside analogues such as stavudine, lamivudine, and zidovudine. In a study with another pegylated interferon alpha, no evidence of a pharmacokinetic or pharmacodynamic (e.g., loss of HIV/HCV virologic suppression) interaction was seen when ribavirin was co-administered with zidovudine, lamivudine, or stavudine in HIV/HCV co-infected subjects [see Clinical Pharmacology (12.3)].

HIV/HCV co-infected subjects who were administered zidovudine in combination with pegylated interferon alpha and ribavirin developed severe neutropenia (ANC <500) and severe anemia (hemoglobin <8 g/dL) more frequently than similar subjects not receiving zidovudine.

Didanosine

Co-administration of REBETOL Capsules or Oral Solution and didanosine is not recommended. Reports of fatal hepatic failure, as well as peripheral neuropathy, pancreatitis, and symptomatic hyperlactactemia/lactic acidosis have been reported in clinical trials [see Clinical Pharmacology (12.3)].

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

PegIntron Monotherapy

Pregnancy Category C: Non-pegylated interferon alfa-2b has been shown to have abortifacient effects in Macaca mulatta (rhesus monkeys) at 15 and 30 million IU/kg (estimated human equivalent of 5 and 10 million IU/kg, based on body surface area adjustment for a 60-kg adult). PegIntron should be assumed to also have abortifacient potential. There are no adequate and well-controlled studies in pregnant women. PegIntron therapy is to be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Therefore, PegIntron is recommended for use in fertile women only when they are using effective contraception during the treatment period.

Use with Ribavirin

Pregnancy Category X: Significant teratogenic and/or embryocidal effects have been demonstrated in all animal species exposed to ribavirin. REBETOL therapy is contraindicated in women who are pregnant and in the male partners of women who are pregnant [see Contraindications (4) and the REBETOL Package Insert].

A Ribavirin Pregnancy Registry has been established to monitor maternal-fetal outcomes of pregnancies in female patients and female partners of male patients exposed to ribavirin during treatment and for 6 months following cessation of treatment. Physicians and patients are encouraged to report such cases by calling 1-800-593-2214.

8.3 Nursing Mothers

It is not known whether the components of PegIntron and/or REBETOL are excreted in human milk. Studies in mice have shown that mouse interferons are excreted in breast milk. Because of the potential for adverse reactions from the drug in nursing infants, a decision must be made whether to discontinue nursing or discontinue the PegIntron and REBETOL treatment, taking into account the importance of the therapy to the mother.

8.4 Pediatric Use

Safety and effectiveness in pediatric patients below the age of 3 years have not been established. Clinical trials in pediatric patients < 3 years of age are not considered feasible due to the small proportion of patients in this age group requiring treatment for CHC.

8.5 Geriatric Use

In general, younger patients tend to respond better than older patients to interferon-based therapies. Clinical studies of PegIntron alone or in combination with REBETOL did not include sufficient numbers of subjects aged 65 and over, however, to determine whether they respond differently than younger subjects. Treatment with alpha interferons, including PegIntron, is associated with neuropsychiatric, cardiac, pulmonary, GI, and systemic (flu-like) adverse effects. Because these adverse reactions may be more severe in the elderly, caution should be exercised in the use of PegIntron in this population. This drug is known to be substantially excreted by the kidney. Because elderly patients are more likely to have decreased renal function, the risk of toxic reactions to this drug may be greater in patients with impaired renal function [see Clinical Pharmacology (12.3)]. When using PegIntron/REBETOL therapy, refer also to the REBETOL Package Insert.

8.6 Organ Transplant Recipients

The safety and efficacy of PegIntron alone or in combination with REBETOL for the treatment of hepatitis C in liver or other organ transplant recipients have not been studied. In a small (n=16) single-center, uncontrolled case experience, renal failure in renal allograft recipients receiving interferon alpha and ribavirin combination therapy was more frequent than expected from the center’s previous experience with renal allograft recipients not receiving combination therapy. The relationship of the renal failure to renal allograft rejection is not clear.

8.7 HIV or HBV Co-infection

The safety and efficacy of PegIntron/REBETOL for the treatment of patients with HCV co-infected with HIV or HBV have not been established.

10 OVERDOSAGE

There is limited experience with overdosage. In the clinical studies, a few subjects accidentally received a dose greater than that prescribed. There were no instances in which a participant in the monotherapy or combination therapy trials received more than 10.5 times the intended dose of PegIntron. The maximum dose received by any subject was 3.45 mcg/kg weekly over a period of approximately 12 weeks. The maximum known overdosage of REBETOL was an intentional ingestion of 10 g (fifty 200 mg capsules). There were no serious reactions attributed to these overdosages. In cases of overdosing, symptomatic treatment and close observation of the patient are recommended.

11 DESCRIPTION

PegIntron, peginterferon alfa-2b, Powder for Injection is a covalent conjugate of recombinant alfa-2b interferon with monomethoxy polyethylene glycol (PEG). The average molecular weight of the PEG portion of the molecule is 12,000 daltons. The average molecular weight of the PegIntron molecule is approximately 31,000 daltons. The specific activity of peginterferon alfa-2b is approximately 0.7 x 10⁸ IU/mg protein.

Interferon alfa-2b is a water-soluble protein with a molecular weight of 19,271 daltons produced by recombinant DNA techniques. It is obtained from the bacterial fermentation of a strain of Escherichia coli bearing a genetically engineered plasmid containing an interferon gene from human leukocytes.

PegIntron is supplied in both vials and the REDIPEN for subcutaneous use.

Vials

Each vial contains either 74 mcg, 118.4 mcg, 177.6 mcg, or 222 mcg of PegIntron as a white to off-white tablet-like solid that is whole/in pieces or as a loose powder, and 1.11 mg dibasic sodium phosphate anhydrous, 1.11 mg monobasic sodium phosphate dihydrate, 59.2 mg sucrose, and 0.074 mg polysorbate 80. Following reconstitution with 0.7 mL of the supplied Sterile Water for Injection USP, each vial contains PegIntron at strengths of either 50 mcg per 0.5 mL, 80 mcg per 0.5 mL, 120 mcg per 0.5 mL, or 150 mcg per 0.5 mL.

REDIPEN

REDIPEN is a dual-chamber glass cartridge containing lyophilized PegIntron as a white to off-white tablet or powder that is whole or in pieces in the sterile active chamber and a second chamber containing Sterile Water for Injection USP. Each PegIntron REDIPEN contains either 67.5 mcg, 108 mcg, 162 mcg, or 202.5 mcg of PegIntron, and 1.013 mg dibasic sodium phosphate anhydrous, 1.013 mg monobasic sodium phosphate dihydrate, 54 mg sucrose, and 0.0675 mg polysorbate 80. Each cartridge is reconstituted to allow for the administration of up to 0.5 mL of solution. Following reconstitution, each REDIPEN contains PegIntron at strengths of either 50 mcg per 0.5 mL, 80 mcg per 0.5 mL, 120 mcg per 0.5 mL, or 150 mcg per 0.5 mL for a single use. Because a small volume of reconstituted solution is lost during preparation of PegIntron, each REDIPEN contains an excess amount of PegIntron powder and diluent to ensure delivery of the labeled dose.

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Pegylated recombinant human interferon alfa-2b is an inducer of the innate antiviral immune response [see Clinical Pharmacology (12.4)].

12.2 Pharmacodynamics

The pharmacodynamic effects of peginterferon alfa-2b include inhibition of viral replication in virus-infected cells, the suppression of cell cycle progression/cell proliferation, induction of apoptosis, anti-angiogenic activities, and numerous immunomodulating activities, such as enhancement of the phagocytic activity of macrophages, activation of NK cells, stimulation of cytotoxic T-lymphocytes, and the upregulation of the Th1 T-helper cell subset.

PegIntron raises concentrations of effector proteins such as serum neopterin and 2’5’ oligoadenylate synthetase, raises body temperature, and causes reversible decreases in leukocyte and platelet counts. The correlation between the in vitro and in vivo pharmacologic and pharmacodynamic and clinical effects is unknown.

12.3 Pharmacokinetics

Following a single subcutaneous dose of PegIntron, the mean absorption half-life (t ½ k_a) was 4.6 hours. Maximal serum concentrations (C_max) occur between 15 and 44 hours postdose, and are sustained for up to 48 to 72 hours. The C_max and AUC measurements of PegIntron increase in a dose-related manner. After multiple dosing, there is an increase in bioavailability of PegIntron. Week 48 mean trough concentrations (320 pg/mL; range 0, 2960) are approximately 3-fold higher than Week 4 mean trough concentrations (94 pg/mL; range 0, 416). The mean PegIntron elimination half-life is approximately 40 hours (range 22-60 hours) in patients with HCV infection. The apparent clearance of PegIntron is estimated to be approximately 22 mL/hr·kg. Renal elimination accounts for 30% of the clearance.

Pegylation of interferon alfa-2b produces a product (PegIntron) whose clearance is lower than that of non-pegylated interferon alfa-2b. When compared to INTRON A, PegIntron (1 mcg/kg) has approximately a 7-fold lower mean apparent clearance and a 5-fold greater mean half-life, permitting a reduced dosing frequency. At effective therapeutic doses, PegIntron has approximately 10-fold greater C_max and 50-fold greater AUC than interferon alfa-2b.

Renal Dysfunction

Following multiple dosing of PegIntron (1 mcg/kg subcutaneously given every week for 4 weeks) the clearance of PegIntron is reduced by a mean of 17% in subjects with moderate renal impairment (creatinine clearance 30-49 mL/min) and by a mean of 44% in subjects with severe renal impairment (creatinine clearance 10-29 mL/min) compared to subjects with normal renal function. Clearance was similar in subjects with severe renal impairment not on dialysis and subjects who are receiving hemodialysis. The dose of PegIntron for monotherapy should be reduced in patients with moderate or severe renal impairment [see Dosage and Administration (2.3) and REBETOL Package Insert]. REBETOL should not be used in patients with creatinine clearance <50 mL/min [see REBETOL Package Insert, WARNINGS].

Gender

During the 48-week treatment period with PegIntron, no differences in the pharmacokinetic profiles were observed between male and female subjects with chronic hepatitis C infection.

Geriatric Patients

The pharmacokinetics of geriatric subjects (>65 years of age) treated with a single subcutaneous dose of 1 mcg/kg of PegIntron were similar in C_max, AUC, clearance, or elimination half-life as compared to younger subjects (28-44 years of age).

Pediatric Patients

Population pharmacokinetics for PegIntron and REBETOL (Capsules and Oral Solution) were evaluated in pediatric subjects with chronic hepatitis C between 3 and 17 years of age. In pediatric patients receiving PegIntron 60 mcg/m²/week subcutaneously, exposure may be approximately 50% higher than observed in adults receiving 1.5 mcg/kg/week subcutaneously. The pharmacokinetics of REBETOL (dose-normalized) in this trial were similar to those reported in a prior study of REBETOL in combination with INTRON A in pediatric subjects and in adult subjects.

Effect of Food on Absorption of Ribavirin

Both AUC_tf and C_max increased by 70% when REBETOL Capsules were administered with a high-fat meal (841 kcal, 53.8 g fat, 31.6 g protein, and 57.4 g carbohydrate) in a single-dose pharmacokinetic study [see Dosage and Administration (2.2)].

Drug Interactions

Drugs Metabolized by Cytochrome P-450

The pharmacokinetics of representative drugs metabolized by CYP1A2 (caffeine), CYP2C8/9 (tolbutamide), CYP2D6 (dextromethorphan), CYP3A4 (midazolam), and N-acetyltransferase (dapsone) were studied in 22 subjects with chronic hepatitis C who received PegIntron (1.5 mcg/kg) once weekly for 4 weeks. PegIntron treatment resulted in a 28% (mean) increase in a measure of CYP2C8/9 activity. PegIntron treatment also resulted in a 66% (mean) increase in a measure of CYP2D6 activity; however, the effect was variable as 13 subjects had an increase, 5 subjects had a decrease, and 4 subjects had no significant change [see Drug Interactions (7.1)].

No significant effect was observed on the pharmacokinetics of representative drugs metabolized by CYP1A2, CYP3A4, or N-acetyltransferase. The effects of PegIntron on CYP2C19 activity were not assessed.

Methadone

The pharmacokinetics of concomitant administration of methadone and PegIntron were evaluated in 18 PegIntron-naïve chronic hepatitis C subjects receiving 1.5 mcg/kg PegIntron subcutaneously weekly. All subjects were on stable methadone maintenance therapy receiving ≥40 mg/day prior to initiating PegIntron. Mean methadone AUC was approximately 16% higher after 4 weeks of PegIntron treatment as compared to baseline. In 2 subjects, methadone AUC was approximately double after 4 weeks of PegIntron treatment as compared to baseline [see Drug Interactions (7.2)].

Use with Ribavirin

Zidovudine, Lamivudine, and Stavudine

Ribavirin has been shown in vitro to inhibit phosphorylation of zidovudine, lamivudine, and stavudine. However, in a study with another pegylated interferon in combination with ribavirin, no pharmacokinetic (e.g., plasma concentrations or intracellular triphosphorylated active metabolite concentrations) or pharmacodynamic (e.g., loss of HIV/HCV virologic suppression) interaction was observed when ribavirin and lamivudine (n=18), stavudine (n=10), or zidovudine (n=6) were co-administered as part of a multi-drug regimen to HIV/HCV coinfected subjects [see Drug Interactions (7.3)].

Didanosine

Exposure to didanosine or its active metabolite (dideoxyadenosine 5'- triphosphate) is increased when didanosine is co-administered with ribavirin, which could cause or worsen clinical toxicities [see Drug Interactions (7.3)].

12.4 Microbiology

Mechanism of Action

The biological activity of PegIntron is derived from its interferon alfa-2b moiety. Peginterferon alfa-2b binds to and activates the human type 1 interferon receptor. Upon binding, the receptor subunits dimerize, and activate multiple intracellular signal transduction pathways. Signal transduction is initially mediated by the JAK/STAT activation, which may occur in a wide variety of cells. Interferon receptor activation also activates NFκB in many cell types. Given the diversity of cell types that respond to interferon alfa-2b, and the multiplicity of potential intracellular responses to interferon receptor activation, peginterferon alfa-2b is expected to have pleiotropic biological effects in the body.

The mechanism by which ribavirin contributes to its antiviral efficacy in the clinic is not fully understood. Ribavirin has direct antiviral activity in tissue culture against many RNA viruses. Ribavirin increases the mutation frequency in the genomes of several viruses and ribavirin triphosphate inhibits HCV polymerase in a biochemical reaction.

Antiviral Activity

The anti-HCV activity of interferon was demonstrated in cell culture using self-replicating HCV-RNA (HCV replicon cells) or HCV infection and resulted in an effective concentration (EC₅₀) value of 1 to 10 IU/mL.

The antiviral activity of ribavirin in the HCV-replicon is not well understood and has not been defined because of the cellular toxicity of ribavirin.

Resistance

HCV genotypes show wide variability in their response to pegylated recombinant human interferon/ribavirin therapy. Genetic changes associated with the variable response have not been identified.

Cross-resistance

There is no reported cross-resistance between pegylated/non-pegylated interferons and ribavirin.

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis and Mutagenesis

PegIntron has not been tested for its carcinogenic potential. Neither PegIntron nor its components, interferon or methoxypolyethylene glycol, caused damage to DNA when tested in the standard battery of mutagenesis assays, in the presence and absence of metabolic activation.

Use with Ribavirin: Ribavirin is genotoxic and mutagenic and should be considered a potential carcinogen. See REBETOL package insert for additional warnings relevant to PegIntron therapy in combination with ribavirin.

Impairment of Fertility

PegIntron may impair human fertility. Irregular menstrual cycles were observed in female cynomolgus monkeys given subcutaneous injections of 4239 mcg/m² PegIntron alone every other day for 1 month (approximately 345 times the recommended weekly human dose based upon body surface area). These effects included transiently decreased serum levels of estradiol and progesterone, suggestive of anovulation. Normal menstrual cycles and serum hormone levels resumed in these animals 2 to 3 months following cessation of PegIntron treatment. Every other day dosing with 262 mcg/m² (approximately 21 times the weekly human dose) had no effects on cycle duration or reproductive hormone status. The effects of PegIntron on male fertility have not been studied.

14 CLINICAL STUDIES

14.1 Chronic Hepatitis C in Adults

PegIntron Monotherapy-Study 1

A randomized study compared treatment with PegIntron (0.5, 1, or 1.5 mcg/kg once weekly subcutaneously) to treatment with INTRON A (3 million units 3 times weekly subcutaneously) in 1219 adults with chronic hepatitis from HCV infection. The subjects were not previously treated with interferon alpha, had compensated liver disease, detectable HCV-RNA, elevated ALT, and liver histopathology consistent with chronic hepatitis. Subjects were treated for 48 weeks and were followed for 24 weeks post-treatment.

Seventy percent of all subjects were infected with HCV genotype 1, and 74 percent of all subjects had high baseline levels of HCV-RNA (more than 2 million copies per mL of serum), 2 factors known to predict poor response to treatment.

Response to treatment was defined as undetectable HCV-RNA and normalization of ALT at 24 weeks post-treatment. The response rates to the 1 and 1.5 mcg/kg PegIntron doses were similar (approximately 24%) to each other and were both higher than the response rate to INTRON A (12%) (see Table 12).

TABLE 12 Rates of Response to Treatment-Study 1
	A PegIntron 0.5 mcg/kg (N=315)	B PegIntron 1 mcg/kg (N=298)	C INTRON A 3 MIU three times weekly (N=307)	B - C (95% CI) Difference between PegIntron 1 mcg/kg and INTRON A
Treatment Response (Combined Virologic Response and ALT Normalization)	17%	24%	12%	11 (5, 18)
Virologic Response^*	18%	25%	12%	12 (6,19)
ALT Normalization	24%	29%	18%	11 (5,18)

^* Serum HCV is measured by a research-based quantitative polymerase chain reaction assay by a central laboratory.

Subjects with both viral genotype 1 and high serum levels of HCV-RNA at baseline were less likely to respond to treatment with PegIntron. Among subjects with the 2 unfavorable prognostic variables, 8% (12/157) responded to PegIntron treatment and 2% (4/169) responded to INTRON A. Doses of PegIntron higher than the recommended dose did not result in higher response rates in these subjects. Subjects receiving PegIntron with viral genotype 1 had a response rate of 14% (28/199) while subjects with other viral genotypes had a 45% (43/96) response rate.

Ninety-six percent of the responders in the PegIntron groups and 100% of responders in the INTRON A group first cleared their viral RNA by Week 24 of treatment [see Dosage and Administration (2)].

The treatment response rates were similar in men and women. Response rates were lower in African-American and Hispanic subjects and higher in Asians compared to Caucasians. Although African Americans had a higher proportion of poor prognostic factors compared to Caucasians, the number of non-Caucasians studied (9% of the total) was insufficient to allow meaningful conclusions about differences in response rates after adjusting for prognostic factors.

Liver biopsies were obtained before and after treatment in 60% of subjects. A modest reduction in inflammation compared to baseline that was similar in all 4 treatment groups was observed.

PegIntron/REBETOL Combination Therapy-Study 2

A randomized study compared treatment with 2 PegIntron/REBETOL regimens [PegIntron 1.5 mcg/kg subcutaneously once weekly/REBETOL 800 mg orally daily (in divided doses); PegIntron 1.5 mcg/kg subcutaneously once weekly for 4 weeks then 0.5 mcg/kg subcutaneously once weekly for 44 weeks/REBETOL 1000 or 1200 mg orally daily (in divided doses)] with INTRON A [3 MIU subcutaneously thrice weekly /REBETOL 1000 or 1200 mg orally daily (in divided doses)] in 1530 adults with chronic hepatitis C. Interferon-naïve subjects were treated for 48 weeks and followed for 24 weeks post-treatment. Eligible subjects had compensated liver disease, detectable HCV-RNA, elevated ALT, and liver histopathology consistent with chronic hepatitis.

Response to treatment was defined as undetectable HCV-RNA at 24 weeks post-treatment. The response rate to the PegIntron 1.5 mcg/kg plus ribavirin 800 mg dose was higher than the response rate to INTRON A/REBETOL (see Table 13). The response rate to PegIntron 1.5→0.5 mcg/kg/REBETOL was essentially the same as the response to INTRON A/REBETOL (data not shown).

TABLE 13 Rates of Response to Treatment – Study 2
	PegIntron 1.5 mcg/kg	INTRON A 3 MIU three
	once weekly REBETOL	times weekly REBETOL
	800 mg daily	1000/1200 mg daily
Overall response ^* †	52% (264/511)	46% (231/505)
Genotype 1	41% (141/348)	33% (112/343)
Genotype 2-6	75%(123/163)	73% (119/162)

^* Serum HCV-RNA is measured with a research-based quantitative polymerase chain reaction assay by a central laboratory.

^† Difference in overall treatment response (PegIntron/REBETOL vs. INTRON A/REBETOL) is 6% with 95% confidence interval of (0.18, 11.63) adjusted for viral genotype and presence of cirrhosis at baseline. Response to treatment was defined as undetectable HCV-RNA at 24 weeks post-treatment.

Subjects with viral genotype 1, regardless of viral load, had a lower response rate to PegIntron (1.5 mcg/kg)/REBETOL (800 mg) compared to subjects with other viral genotypes. Subjects with both poor prognostic factors (genotype 1 and high viral load) had a response rate of 30% (78/256) compared to a response rate of 29% (71/247) with INTRON A/REBETOL.

Subjects with lower body weight tended to have higher adverse reaction rates [see Adverse Reactions (6.1)] and higher response rates than subjects with higher body weights. Differences in response rates between treatment arms did not substantially vary with body weight.

Treatment response rates with PegIntron/REBETOL were 49% in men and 56% in women. Response rates were lower in African American and Hispanic subjects and higher in Asians compared to Caucasians. Although African Americans had a higher proportion of poor prognostic factors compared to Caucasians, the number of non-Caucasians studied (11% of the total) was insufficient to allow meaningful conclusions about differences in response rates after adjusting for prognostic factors in this study.

Liver biopsies were obtained before and after treatment in 68% of subjects. Compared to baseline, approximately two-thirds of subjects in all treatment groups were observed to have a modest reduction in inflammation.

PegIntron/REBETOL Combination Therapy-Study 3

In a large United States community-based study (Study 3), 4913 subjects with chronic hepatitis C were randomized to receive PegIntron 1.5 mcg/kg subcutaneously once weekly in combination with a REBETOL dose of 800 to 1400 mg (weight-based dosing [WBD]) or 800 mg (flat) orally daily (in divided doses) for 24 or 48 weeks based on genotype. Response to treatment was defined as undetectable HCV-RNA (based on an assay with a lower limit of detection of 125 IU/mL) at 24 weeks post-treatment.

Treatment with PegIntron 1.5 mcg/kg and REBETOL 800 to 1400 mg resulted in a higher sustained virologic response compared to PegIntron in combination with a flat 800 mg daily dose of REBETOL. Subjects weighing >105 kg obtained the greatest benefit with WBD, although a modest benefit was also observed in subjects weighing >85 to 105 kg (see Table 14). The benefit of WBD in subjects weighing >85 kg was observed with HCV genotypes 1 through 3. Insufficient data were available to reach conclusions regarding other genotypes. Use of WBD resulted in an increased incidence of anemia [see Adverse Reactions (6.1)].

TABLE 14 SVR Rate by Treatment and Baseline Weight- Study 3
Treatment Group	Subject Baseline Weight
	<65 kg (<143 lb)	65-85 kg (143-188 lb)	>85-105 kg (>188-231 lb)	>105 kg (>231 lb)
WBD*	50% (173/348)	45% (449/994)	42% (351/835)	47% (138/292)
Flat	51% (173/342)	44% (443/1011)	39% (318/819)	33% (91/272)

* P=0.01, primary efficacy comparison (based on data from subjects weighing 65 kg or higher

at baseline and utilizing a logistic regression analysis that includes treatment [WBD or Flat],

genotype and presence/absence of advanced fibrosis, in the model).

A total of 1552 subjects weighing >65 kg in Study 3 had genotype 2 or 3 and were randomized to 24 or 48 weeks of therapy. No additional benefit was observed with the longer treatment duration.

PegIntron/REBETOL Combination Therapy-Study 4

A large randomized study compared the safety and efficacy of treatment for 48 weeks with two PegIntron/REBETOL regimens [PegIntron 1.5 mcg/kg and 1 mcg/kg subcutaneously once weekly both in combination with REBETOL 800 to 1400 mg PO daily (in two divided doses)] and Pegasys 180 mcg subcutaneously once weekly in combination with Copegus 1000 to 1200 mg PO daily (in two divided doses) in 3070 treatment-naïve adults with chronic hepatitis C genotype 1. In this study, lack of early virologic response by treatment Week 12 (subjects who do not achieve undetectable HCV-RNA or ≥2 log₁₀ reduction from baseline) was the criteria for discontinuation of treatment. Sustained Virologic Response (SVR) to the treatment was defined as undetectable HCV-RNA (Roche COBAS TaqMan assay, a lower limit of quantitation of 27 IU/mL) at 24 weeks posttreatment [see Table 15].

Table 15 Response Rate by Treatment
Treatment Group	% (number) of Patients
	PegIntron 1.5 mcg/kg /REBETOL	PegIntron 1 mcg/kg REBETOL	Pegasys 180 mcg /Copegus
SVR	40 (406/1019)	38 (386/1016)	41 (423/1035)

In all three treatment groups, overall SVR rates were similar. In subjects with poor prognostic factors, subjects randomized to PegIntron (1.5 mcg/kg)/REBETOL or Pegasys/Copegus achieved higher SVR rates compared to those randomized to the PegIntron 1 mcg/kg/REBETOL arm. In all arms, SVR rates were lower in subjects with poor prognostic factors compared to those without. For the PegIntron 1.5 mcg/kg plus REBETOL dose, SVR rates for those with and without, respectively, the following baseline factors were as follows: cirrhosis (10% vs. 42%), normal ALT levels (32% vs. 42%), baseline viral load >600,000 IU/mL (35% vs. 61%), >40 years old (38% vs. 50%), and African American subjects (23% vs. 44%). In subjects with undetectable HCV-RNA at treatment week 12 who received PegIntron (1.5 mcg/kg)/REBETOL, the SVR rate was 81% (328/407).

PegIntron/REBETOL Combination Therapy in Prior Treatment Failures-Study 5

In a noncomparative trial, 2293 patients with moderate to severe fibrosis who failed previous treatment with combination alpha interferon/ribavirin were retreated with PegIntron, 1.5 mcg/kg subcutaneously, once weekly, in combination with weight adjusted ribavirin. Eligible patients included prior nonresponders (patients who were HCV-RNA positive at the end of a minimum 12 weeks of treatment) and prior relapsers (patients who were HCV-RNA negative at the end of a minimum 12 weeks of treatment and subsequently relapsed after posttreatment follow-up). Patients who were negative at week 12 were treated for 48 weeks and followed for 24 weeks posttreatment. Response to treatment was defined as undetectable HCV-RNA at 24 weeks posttreatment (measured using a research-based test, limit of detection 125 IU/mL). The overall response rate was 22% (497/2293) (99% CI: 19.5, 23.9). Patients with the following characteristics were less likely to benefit from retreatment: previous nonresponse, previous pegylated interferon treatment, significant bridging fibrosis or cirrhosis, and genotype 1 infection.

The retreatment sustained virologic response rates by baseline characteristics are summarized in Table 16.

Table 16 SVR Rates by Baseline Characteristics of Prior Treatment Failures.
HCV Genotype/ Metavir Fibrosis Score	Overall SVR by Previous Response and Treatment
	Nonresponder		Relapser
	alfa interferon/ribavirin % (number of patients)	peginterferon (2a and 2b combined)/ribavirin % (number of patients)	alfa interferon /ribavirin % (number of patients)	peginterferon (2a and 2b combined)/ribavirin % (number of patients)
Overall	18 (158/903)	6 (30/476)	43 (130/300)	35 (113/344)
HCV 1	13 (98/761)	4 (19/431)	32 (67/208)	23 (56/243)
F2	18 (36/202)	6 (7/117)	42 (33/79)	32 (23/72)
F3	16 (38/233)	4 (4/112)	28 (16/58)	21 (14/67)
F4	7 (24/325)	4 (8/202)	26 (18/70)	18 (19/104)
HCV 2/3	49 (53/109)	36 (10/28)	67 (54/81)	57 (52/92)
F2	68 (23/34)	56 (5/9)	76 (19/25)	61 (11/18)
F3	39 (11/28)	38 (3/8)	67 (18/27)	62 (18/29)
F4	40 (19/47)	18 (2/11)	59 (17/29)	51 (23/45)
HCV 4	17 (5/29)	7 (1/15)	88 (7/8)	50 (4/8)

Achievement of an undetectable HCV-RNA at treatment week 12 was a strong predictor of sustained virologic response (SVR). In this trial, 1470 (64%) subjects did not achieve an undetectable HCV-RNA at treatment week 12, and were offered enrollment into long-term treatment trials, due to an inadequate treatment response. Of the 823 (36%) subjects who were HCV-RNA undetectable at treatment week 12, those infected with genotype 1 had an SVR of 48% (245/507), with a range of responses by fibrosis scores (F4-F2) of 39-55%. Subjects infected with genotype 2/3 who were HCV-RNA undetectable at treatment week 12 had an overall SVR of 70% (196/281), with a range of responses by fibrosis scores (F4-F2) of 60-83%. For all genotypes, higher fibrosis scores were associated with a decreased likelihood of achieving SVR.

14.2 Chronic Hepatitis C in Pediatrics

PegIntron/REBETOL Combination Therapy-Pediatric Study

Previously untreated pediatric subjects 3 to 17 years of age with compensated chronic hepatitis C and detectable HCV-RNA were treated with REBETOL 15 mg/kg/day plus PegIntron 60 mcg/m² once weekly for 24 or 48 weeks based on HCV genotype and baseline viral load. All subjects were to be followed for 24 weeks post-treatment. A total of 107 subjects received treatment of whom 52% were female, 89% were Caucasian, and 67% were infected with HCV Genotype 1. Subjects infected with Genotype 1, 4 or Genotype 3 with HCV-RNA ≥ 600,000 IU/mL received 48 weeks of therapy while those infected with Genotype 2 or Genotype 3 with HCV-RNA < 600,000 IU/mL received 24 weeks of therapy. The study results are summarized in Table 17.

Table 17 Sustained Virologic Response Rates by Genotype and Treatment Duration – Pediatric Study
	All Subjects n=107
	24 Weeks	48 Weeks
	Virologic Response n^* † (%)	Virologic Response n^* † (%)
Genotype
All	26/27(96.3)	44/80(55.0)
1	-	38/72(52.8)
2	14/15(93.3)	-
3^‡	12/12(100)	2/3(66.7)
4	-	4/5(80.0)
^*Response to treatment was defined as undetectable HCV-RNA at 24 weeks post-treatment. ^†n = number of responders/number of subjects with given genotype, and assigned treatment duration. ^‡Subjects with genotype 3 low viral load (<600,000 IU/mL) were to receive 24 weeks of treatment while those with genotype 3 and high viral load were to receive 48 weeks of treatment.

16 HOW SUPPLIED/STORAGE AND HANDLING PegIntron REDIPEN
Each PegIntron REDIPEN Package Contains:
A box containing one 50 mcg per 0.5 mL PegIntron REDIPENand 1 BD needle and 2 alcohol swabs.	(NDC 0085-1323-01)
A box containing one 80 mcg per 0.5 mL PegIntron REDIPEN and1 BD needle and 2 alcohol swabs.	(NDC 0085-1316-01)
A box containing one 120 mcg per 0.5 mL PegIntron REDIPENand 1 BD needle and 2 alcohol swabs.	(NDC 0085-1297-01)
A box containing one 150 mcg per 0.5 mL PegIntron REDIPENand 1 BD needle and 2 alcohol swabs.	(NDC 0085-1370-01)

Each PegIntron REDIPEN PAK 4 Contains:
A box containing four 50 mcg per 0.5 mL PegIntron REDIPENUnits, each containing 1 BD needle and 2 alcohol swabs.	(NDC 0085-1323-02)
A box containing four 80 mcg per 0.5 mL PegIntron REDIPENUnits, each containing 1 BD needle and 2 alcohol swabs.	(NDC 0085-1316-02)
A box containing four 120 mcg per 0.5 mL PegIntron REDIPENUnits, each containing 1 BD needle and 2 alcohol swabs.	(NDC 0085-1297-02)
A box containing four 150 mcg per 0.5 mL PegIntron REDIPEN Units, each containing 1 BD needle and 2 alcohol swabs.	(NDC 0085-1370-02)

PegIntron Vials
Each PegIntron Package Contains:
A box containing one 50 mcg per 0.5 mL vial of PegIntron Powder for Injection and one 1.25 mL vial of Diluent (Sterile Water for Injection USP), 2 BD Safety Lok syringes with a safety sleeve and 2 alcohol swabs.	(NDC 0085-1368-01)
A box containing one 80 mcg per 0.5 mL vial of PegIntron Powder for Injection and one 1.25 mL vial of Diluent (Sterile Water for Injection USP), 2 BD Safety Lok syringes with a safety sleeve and 2 alcohol swabs.	(NDC 0085-1291-01)
A box containing one 120 mcg per 0.5 mL vial of PegIntron Powder for Injection and one 1.25 mL vial of Diluent (Sterile Water for Injection USP), 2 BD Safety Lok syringes with a safety sleeve and 2 alcohol swabs.	(NDC 0085-1304-01)
A box containing one 150 mcg per 0.5 mL vial of PegIntron Powder for Injection and one 1.25 mL vial of Diluent (Sterile Water for Injection USP), 2 BD Safety Lok syringes with a safety sleeve and 2 alcohol swabs.	(NDC 0085-1279-01)

Storage

PegIntron REDIPEN

PegIntron REDIPEN should be stored at 2°-8°C (36°-46°F).

After reconstitution, the solution should be used immediately, but may be stored up to 24 hours at 2°-8°C (36°-46°F). The reconstituted solution contains no preservative, and is clear and colorless. DO NOT FREEZE. Keep away from heat.

PegIntron Vials

PegIntron should be stored at 25°C (77°F); excursions permitted to 15°-30°C (59-86°F) [see USP Controlled Room Temperature]. After reconstitution with supplied Diluent the solution should be used immediately, but may be stored up to 24 hours at 2°-8°C (36°-46°F). The reconstituted solution contains no preservative, and is clear and colorless. DO NOT FREEZE. Keep away from heat.

Disposal Instructions

Patients should be thoroughly instructed in the importance of proper disposal. After preparation and administration of PegIntron for Injection, patients should be advised to use a puncture-resistant container for the disposal of used syringes, needles, and the REDIPEN. The full container should be disposed of in accordance with state and local laws. Patients should also be cautioned against reusing or sharing needles, syringes, or the REDIPEN.

17 PATIENT COUNSELING INFORMATION

• “See FDA-approved patient labeling (Medication Guide and Instructions for Use)”

A patient should self-inject PegIntron only if it has been determined that it is appropriate, the patient agrees to medical follow-up as necessary, and training in proper injection technique has been given to him/her.

17.1 Pregnancy

Patients must be informed that REBETOL may cause birth defects and death of the unborn child. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients during treatment with combination PegIntron/REBETOL therapy and for 6 months post-therapy. Combination PegIntron/REBETOL therapy should not be initiated until a report of a negative pregnancy test has been obtained immediately prior to initiation of therapy. It is recommended that patients undergo monthly pregnancy tests during therapy and for 6 months post-therapy [see Contraindications (4), Use in Specific Populations (8.1), and REBETOL package insert].

17.2 HCV Transmission

Inform patients that there are no data regarding whether PegIntron therapy will prevent transmission of HCV infection to others. Also, it is not known if treatment with PegIntron will cure hepatitis C or prevent cirrhosis, liver failure, or liver cancer that may be the result of infection with the hepatitis C virus.

17.3 Laboratory Evaluations, Hydration, “Flu-like” Symptoms

Patients should be advised that laboratory evaluations are required before starting therapy and periodically thereafter [see Warnings and Precautions (5.15)]. It is advised that patients be well hydrated, especially during the initial stages of treatment. “Flu-like” symptoms associated with administration of PegIntron may be minimized by bedtime administration of PegIntron or by use of antipyretics.

Patients developing fever, cough, shortness of breath or other symptoms of a lung problem during treatment with PegIntron may need to have a chest X-ray or other tests to adequately treat them.

17.4 Instructions for Use

Patients receiving PegIntron should be directed in its appropriate preparation, handling, measurement, and injection, and referred to the Instructions for Use for PegIntron Powder for Solution and PegIntron REDIPEN.

Patients should be directed to store PegIntron before mixing as follows:

• PegIntron REDIPEN: store in the refrigerator between 36°F to 46°F (2°C to 8°C)
• PegIntron Powder for Solution: store at room temperature between 59°F to 86°F (15°C to 30°C)

Patients should be instructed on the importance of site selection for self-administering the injection, as well as the importance on rotating the injection sites.

Manufactured by: Schering Corporation, a subsidiary of Merck & Co., Inc., Whitehouse Station, NJ 08889, USA.

U.S. Patent Nos. 5,908,621; 5,951,974; 6,042,822; 6,177,074; 6,180,096; 6,250,469; 6,482,613; 6,524,570; and 6,610,830.

Copyright © 2001, 2010 Schering Corporation, a subsidiary of Merck & Co., Inc. All rights reserved

BD and Safety-Lok are registered trademarks of Becton, Dickinson and Company.

B-33538847T

LRN#054031-PGI-MTL-USPI-50

MEDICATION GUIDE

PegIntron ® (peg-In-tron)

(Peginterferon alfa-2b)

Read this Medication Guide before you start taking PegIntron, and each time you get a refill. There may be new information. This information does not take the place of talking with your healthcare provider about your medical condition or your treatment.

If you are taking PegIntron with REBETOL, also read the Medication Guide for REBETOL (ribavirin) Capsules and Oral Solution.

PegIntron by itself or with REBETOL is a treatment for some people who are infected with hepatitis C virus.

What is the most important information I should know about PegIntron?

PegIntron can cause serious side effects that:

• may cause death, or
• may worsen certain serious diseases that you may already have.

Tell your healthcare provider right away if you have any of the symptoms listed below while taking PegIntron:

1. Mental health problems and suicide. PegIntron may cause you to develop mood or behavior problems, including:

• irritability (getting upset easily)
• depression (feeling low, feeling bad about yourself, or feeling hopeless)
• aggressive behavior
• thoughts of hurting yourself or others, or suicide
• former drug addicts may fall back into drug addiction or overdose

2. Heart problems. Some people who take PegIntron may get heart problems, including:

• low blood pressure
• fast heart rate or abnormal heart beat
• trouble breathing or chest pain
• heart attacks or heart muscle problems (cardiomyopathy)

3. Stroke or symptoms of a stroke. Symptoms may include weakness, loss of coordination, and numbness. Stroke or symptoms of a stroke may happen in people who have some risk factors or no known risk factors for a stroke.

4. New or worsening autoimmune problems. Some people taking PegIntron develop autoimmune problems (a condition where the body's immune cells attack other cells or organs in the body), including rheumatoid arthritis, systemic lupus erythematosus, and psoriasis. In some people who already have an autoimmune problem, it may get worse during your treatment with PegIntron.

5. Infections. Some people who take PegIntron may get an infection. Symptoms may include:

• fever
• chills
• bloody diarrhea
• burning or pain with urination
• urinating often
• coughing up mucus (phlegm) that is discolored (for example, yellow or pink)

6. Pregnancy. Do not take PegIntron with REBETOL if you are pregnant or planning to get pregnant or breastfeeding.

See “What should I tell my healthcare provider before taking PegIntron?”

While taking PegIntron, you should see a healthcare provider regularly for check-ups and blood tests to make sure that your treatment is working, and to check for side effects.

What is PegIntron?

PegIntron is a prescription medicine that is used:

• with REBETOL to treat chronic (lasting a long time) hepatitis C infection in people 3 years and older with certain types of liver disease.
• alone, sometimes to treat adults who have chronic (lasting a long time) hepatitis C infection with certain types of liver disease.

People with hepatitis C have the virus in their blood and in their liver. PegIntron reduces the amount of virus in the body and helps the body's immune system fight the virus. REBETOL (ribavirin) is a drug that helps to fight the viral infection but does not work when used by itself to treat chronic hepatitis C.

It is not known if PegIntron use for longer than 1 year is safe and will work.

It is not known if PegIntron use in children younger than 3 years old is safe and will work.

Who should not take PegIntron?

Do not take PegIntron:

• if you have had a serious allergic reaction to another alpha interferon or to any of the ingredients in PegIntron. See the end of this Medication Guide for a complete list of ingredients. Ask your healthcare provider if you are not sure.
• if you have certain types of hepatitis (autoimmune hepatitis).
• if you have certain other liver problems.
• with REBETOL if you are pregnant, planning to get pregnant, or breastfeeding.

Talk to your healthcare provider before taking PegIntron if you have any of these conditions.

What should I tell my healthcare provider before taking PegIntron?

Before you take PegIntron, tell your healthcare provider if you:

• See “What is the most important information I should know about PegIntron?”
• are being treated for a mental illness or had treatment in the past for any mental illness, including depression and suicidal behavior
• have or ever had any problems with your heart, including heart attack or high blood pressure
• have any kind of autoimmune disease (where the body's immune system attacks the body's own cells), such as psoriasis, systemic lupus erythematosus, rheumatoid arthritis
• have or ever had bleeding problems or a blood clot
• have or ever had low blood cell counts
• have ever been addicted to drugs or alcohol
• have liver disease (other than hepatitis C infection)
• have or had lung disease such as chronic obstructive pulmonary disease (COPD)
• have thyroid problems
• have diabetes
• have colitis (inflammation of your intestine)
• have a condition that suppresses your immune system, such as cancer
• have hepatitis B infection
• have HIV infection
• have kidney problems
• have high blood triglyceride levels (fat in your blood)
• have an organ transplant and are taking medicine that keeps your body from rejecting your transplant (suppresses your immune system)
• have any other medical conditions
• are pregnant or plan to become pregnant. It is not known if PegIntron will harm your unborn baby. You should use effective birth control during treatment with PegIntron. Talk to your healthcare provider about birth control choices for you during treatment with PegIntron. Tell your healthcare provider if you become pregnant during treatment with PegIntron.
• are breastfeeding or plan to breastfeed. It is not known if PegIntron passes into your breast milk. You and your healthcare provider should decide if you will use PegIntron or breastfeed.

Tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. PegIntron and certain other medicines may affect each other and cause side effects.

Especially tell your doctor if you take the anti-hepatitis B medicine telbivudine (Tyzeka).

Know the medicines you take. Keep a list of them and show it to your healthcare provider and pharmacist when you get a new medicine.

How should I take PegIntron?

• Take PegIntron exactly as your healthcare provider tells you to. Your healthcare provider will tell you how much PegIntron to take and when to take it. Do not take more than your prescribed dose.
• Take your prescribed dose of PegIntron every week, on the same day of each week and at the same time.
• PegIntron is given as an injection under your skin (subcutaneous injection). Your healthcare provider should show you how to prepare and measure your dose of PegIntron, and how to inject yourself before you use PegIntron for the first time.
• You should not inject PegIntron until your healthcare provider has shown you how to use PegIntron the right way.
• PegIntron comes as a powder in a single-use vial and as a single-use REDIPEN. Your doctor will prescribe the PegIntron that is right for you. See the Instructions for Use that comes with your PegIntron for detailed instructions for preparing and injecting a dose of PegIntron.
• If you miss a dose of PegIntron, take the missed dose as soon as possible during the same day or the next day, then continue on your regular dosing schedule. If several days go by after you miss a dose, check with your healthcare provider about what to do.
• Do not inject more than 1 dose of PegIntron in one week without talking to your healthcare provider.
• If you take too much PegIntron, call your healthcare provider right away. Your healthcare provider may examine you more closely, and do blood tests.
• Your healthcare provider should do regular blood tests before you start PegIntron, and during treatment to see how well the treatment is working and to check you for side effects.

What are the possible side effects of PegIntron?

PegIntron may cause serious side effects including:

• See "What is the most important information I should know about PegIntron?"
• Serious eye problems. PegIntron may cause eye problems that may lead to vision loss or blindness. You should have an eye exam before you start taking PegIntron. If you have eye problems or have had them in the past, you may need eye exams while you are taking PegIntron. Tell your healthcare provider or eye doctor right away if you have any vision changes while taking PegIntron.
• Blood problems. PegIntron can affect your bone marrow and cause low white blood cell and platelet counts. In some people, these blood counts may fall to dangerously low levels. If your blood counts become very low, you can get infections, and problems with bleeding and bruising.
• Swelling of your pancreas (pancreatitis) or intestines (colitis). Symptoms may include:
  • severe stomach area (abdomen) pain
  • severe back pain
  • nausea and vomiting
  • bloody diarrhea
  • fever
• Lung problems including:
  • trouble breathing
  • pneumonia
  • inflammation of lung tissue
  • new or worse high blood pressure of the lungs (pulmonary hypertension). This can be severe and may lead to death.

You may need to have a chest X-ray or other tests if you develop fever, cough, shortness of breath or other symptoms of a lung problem during treatment with PegIntron.

• Severe liver problems, or worsening of liver problems, including liver failure and death. Symptoms may include:
  • nausea
  • loss of appetite
  • tiredness
  • diarrhea
  • yellowing of your skin or the white part of your eyes
  • bleeding more easily than normal
  • swelling of your stomach area (abdomen)
  • confusion
  • sleepiness
  • you cannot be awakened (coma)
• Thyroid problems. Some people develop changes in their thyroid function. Symptoms of thyroid changes include:
  • problems concentrating
  • feeling cold or hot all of the time
  • weight changes
  • skin changes
  • Blood sugar problems. Some people may develop high blood sugar or diabetes. If you have high blood sugar or diabetes that is not controlled before starting PegIntron, talk to your healthcare provider before you take PegIntron. If you develop high blood sugar or diabetes while taking PegIntron, your healthcare provider may tell you to stop PegIntron and prescribe a different medicine for you. Symptoms of high blood sugar or diabetes may include:
    • increased thirst
    • tiredness
    • urinating more often than normal
    • increased appetite
    • weight loss
    • your breath smells like fruit
  • Serious allergic reactions and skin reactions. Symptoms may include:
    • itching
    • swelling of the face, eyes, lips, tongue, or throat
    • trouble breathing
    • anxiousness
    • chest pain
    • feeling faint
    • skin rash, hives, sores in your mouth, or your skin blisters and peels
  • Growth problems in children. Weight loss and slowed growth are common in children during treatment with PegIntron.
  • Nerve problems. People who take PegIntron or other alpha interferon products with telbivudine (Tyzeka) can develop nerve problems such as continuing numbness, tingling, or burning sensation in the arms or legs (peripheral neuropathy). Call your healthcare provider if you have any of these symptoms.
  Tell your doctor right away if you have any of the symptoms listed above.The most common side effects of PegIntron include:
  • Flu-like symptoms. Symptoms may include: headache, muscle aches, tiredness, and fever. Some of these symptoms may be decreased by injecting your PegIntron dose at bedtime. Talk to your healthcare provider about which over-the-counter medicines you can take to help prevent or decrease some of these symptoms.
  • Tiredness. Many people become very tired during treatment with PegIntron.
  • Appetite problems. Nausea, loss of appetite, and weight loss can happen with PegIntron.
  • Skin reactions. Redness, swelling, and itching are common at the site of injection.
  • Hair thinning.
  Tell your healthcare provider if you have any side effect that bothers you or that does not go away.These are not all of the possible side effects of PegIntron. For more information, ask your healthcare provider or pharmacist.Call your doctor for medical advice about side effects. You may report side effects to FDA at 1–800–FDA–1088.How should I store PegIntron?
  • Before mixing, store PegIntron REDIPEN in the refrigerator between 36°F to 46°F (2°C to 8°C).
  • Before mixing, store PegIntron vials at room temperature between 59°F to 86°F (15°C to 30°C).
  • Keep PegIntron away from heat.
  • After mixing, use PegIntron right away or store it in the refrigerator for up to 24 hours between 36°F to 46°F (2°C to 8°C).
  • Do not freeze PegIntron.
  • Keep PegIntron and all medicines out of the reach of children.
  General Information about PegIntronMedicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use PegIntron for a condition for which it was not prescribed. Do not give PegIntron to other people, even if they have the same symptoms that you have. It may harm them.This Medication Guide summarizes the most important information about PegIntron. If you would like more information, ask your healthcare provider. You can ask your healthcare provider or pharmacist for information about PegIntron that was written for healthcare professionals.For more information, go to www.PegIntron.com or call 1-800-526-4099.What are the ingredients in PegIntron?Active ingredients: peginterferon alfa-2bInactive ingredients: dibasic sodium phosphate anhydrous, monobasic sodium phosphate dihydrate, sucrose, polysorbate 80. Sterile water for injection is supplied as a diluent.Manufactured by: Schering Corporation, a subsidiary of Merck & Co., Inc., Whitehouse Station, NJ 08889, USA.The Medication Guide has been approved by the U.S. Food and Drug Administration.Copyright © 2001, 2008 Schering Corporation, a subsidiary of Merck & Co., Inc.
  All rights reservedRevised: February 2011B-35038701T

LRN#054031-PGI-MTL-MG-3

Instructions for Use

PegIntron ® (peg-In-tron)

(Peginterferon alfa-2b)

Powder for Solution

Be sure that you read, understand and follow these instructions before injecting PegIntron Solution. Your healthcare provider should show you how to prepare, measure, and inject PegIntron properly before you use it for the first time. Ask your healthcare provider if you have any questions.

Before starting, collect all of the supplies that you will need to use for preparing and injecting PegIntron. For each injection you will need a PegIntron vial package that contains:

• 1 vial of PegIntron powder for solution
• 1 vial of sterile water for injection (diluent)
• 2 single-use disposable syringes (BD Safety Lok syringes with a safety sleeve)
• 2 alcohol swabs

You will also need:

• 1 cotton ball or gauze
• a puncture-proof disposable container to throw away used syringes, needles, and vials.

Important:

• Never re-use disposable syringes and needles.
• The vial of mixed PegIntron should be used right away. Do not mix more than 1 vial of PegIntron at a time. If you do not use the vial of the prepared solution right away, store it in a refrigerator and use within 24 hours. See the end of these Instructions for Use for information about “How should I store PegIntron?”
• Make sure you have the right syringe and needle to use with PegIntron. Your healthcare provider should tell you what syringes and needles to use to inject PegIntron.

How should I prepare a dose of PegIntron?

Before you inject PegIntron, the powder must be mixed with 0.7 mL of the sterile water for injection (diluent) that comes in the PegIntron vial package.

1. Find a clean, well-lit, flat work surface.

2. Get 1 of your PegIntron vial packages. Check the date printed on the PegIntron carton. Make sure that the expiration date has not passed. Do not use your PegIntron vial packages if the expiration date has passed. The medicine in the PegIntron vial should look like a white to off-white tablet that is whole, or in pieces, or powdered.

If you have already mixed the PegIntron solution and stored it in the refrigerator, take it out of the refrigerator before use and allow the solution to come to room temperature. See the Medication Guide section “How should I store PegIntron?”

3. Wash your hands well with soap and water, rinse and towel dry (see Figure 1). Keep your work area, your hands, and injection site clean to decrease the risk of infection.

(Graphic Omitted)

The disposable syringes have needles that are already attached and cannot be removed. Each syringe has a clear plastic safety sleeve that is pulled over the needle for disposal after use. The safety sleeve should remain tight against the flange while using the syringe and moved over the needle only when ready for disposal. (See Figure 2.)

(Graphic Omitted)

4. Remove the protective wrapper from one of the syringes provided. Use the syringe for steps 4 through 15. Make sure that the syringe safety sleeve is sitting against the flange. (See Figure 2.)

5. Remove the protective plastic cap from the tops of both the sterile water for injection (diluent) and the PegIntron vials (see Figure 3). Clean the rubber stopper on the top of both vials with an alcohol swab.

(Graphic Omitted)

6. Carefully remove the protective cap straight off of the needle to avoid damaging the needle point.

7. Fill the syringe with air by pulling back on the plunger to 0.7 mL. (See Figure 4.)

(Graphic Omitted)

8. Hold the diluent vial upright. Do not touch the cleaned top of the vial with your hands.

• Push the needle through the center of the rubber stopper of the diluent vial. (See Figure 5.)

• Slowly inject all the air from the syringe into the air space above the diluent in the vial. (See Figure 6.)

(Graphic Omitted)

9. Turn the vial upside down and make sure the tip of the needle is in the liquid.

10. Withdraw only 0.7 mL of diluent by pulling the plunger back to the 0.7 mL mark on the side of the syringe. (See Figure 7.)

(Graphic Omitted)

11. With the needle still inserted in the vial, check the syringe for air bubbles.

• If there are any air bubbles, gently tap the syringe with your finger until the air bubbles rise to the top of the syringe.
• Slowly push the plunger up to remove the air bubbles.
• If you push diluent back into the vial, slowly pull back on the plunger to draw the correct amount of diluent back into the syringe.

12. Remove the needle from the vial. (See Figure 8.) Do not let the syringe touch anything.

(Graphic Omitted)

13. Throw away any diluent that is left over in the vial.

14. Insert the needle through the center of the rubber stopper of the PegIntron powder vial. Do not touch the cleaned rubber stopper.

• Place the needle tip, at an angle, against the side of the vial. (See Figure 9.)
• Slowly push the plunger down to inject the 0.7 mL diluent. The stream of diluent should run down the side of the vial.
• To prevent bubbles from forming, do not aim the stream of diluent directly on the medicine in the bottom of the vial.

(Graphic Omitted)

15. Remove the needle from the vial.

• Firmly grasp the safety sleeve and pull it over the exposed needle until you hear a click (see Figure 10). The green stripe on the safety sleeve will completely cover the red stripe on the needle. Discard the syringe, needle, and vial in the puncture-proof container.

(Graphic Omitted)

16. Gently swirl the vial in a gentle circular motion, until the PegIntron is completely dissolved (mixed together). (See Figure 11.)

• Do not shake the vial. If any powder remains undissolved in the vial, gently turn the vial upside down until all of the powder is dissolved.
• The solution may look cloudy or bubbly for a few minutes. If air bubbles form, wait until the solution settles and all bubbles rise to the top.

(Graphic Omitted)

17. After the PegIntron completely dissolves, the solution should be clear, colorless and without particles. It is normal to see a ring of foam or bubbles on the surface.

Do not use the mixed solution if you see particles in it, or it is not clear and colorless. Throw away the syringe and needle in the puncture-proof container. (See the section "How should I dispose of the used syringes, needles, and vials?".) Then, repeat steps 1 through 23 with a new vial of PegIntron and diluent to prepare a new syringe.

18. After the PegIntron powder completely dissolves, clean the rubber stopper again with an alcohol swab before you withdraw your dose.

19. Unwrap the second syringe provided. You will use it to give yourself the injection.

• Carefully remove the protective cap from the needle. Fill the syringe with air by pulling the plunger to the number on the side of the syringe (mL) that matches your prescribed dose. (See Figure 12.)

(Graphic Omitted)

• Hold the PegIntron vial upright. Do not touch the cleaned top of the vial with your hands. (See Figure 13.)

(Graphic Omitted)

• Insert the needle into the vial containing the PegIntron solution. Inject the air into the center of the vial. (See Figure 14.)

(Graphic Omitted)

20. Turn the PegIntron vial upside down. Be sure the tip of the needle is in the PegIntron solution.

• Hold the vial and syringe with one hand. Be sure the tip of the needle is in the PegIntron Solution. With the other hand, slowly pull the plunger back to fill the syringe with the exact amount of PegIntron into the syringe your healthcare provider told you to use. (See Figure 15.)

(Graphic Omitted)

21. Check for air bubbles in the syringe. If you see any air bubbles, hold the syringe with the needle pointing up. Gently tap the syringe until the air bubbles rise. Then, slowly push the plunger up to remove any air bubbles. If you push solution into the vial, slowly pull back on the plunger again to draw the correct amount of PegIntron back into the syringe. When you are ready to inject the medicine, remove the needle from the vial. (See Figure 16.)

(Graphic Omitted)

How should I choose a site for injection?

The best sites for giving yourself an injection are those areas with a layer of fat between the skin and muscle, like your thigh, the outer surface of your upper arm, and abdomen (see Figure 17). Do not inject yourself in the area near your navel or waistline. If you are very thin, you should only use the thigh or outer surface of the arm for injection.

(Graphic Omitted)

You should use a different site each time you inject PegIntron to avoid soreness at any one site. Do not inject PegIntron solution into an area where the skin is irritated, red, bruised, infected or has scars, stretch marks, or lumps.

How should I inject a dose of PegIntron?

22. Clean the skin where the injection is to be given with an alcohol swab. Wait for the area to dry.

• Make sure the safety sleeve of the syringe is pushed firmly against the syringe flange so that the needle is fully exposed. (See Figure 2.)
  

23. With one hand, pinch a fold of skin. With your other hand, pick up the syringe and hold it like a pencil.

• Insert the needle into the pinched skin at a 45- to 90-degree angle with a quick dart-like motion (see Figure 18).

(Graphic Omitted)

• After the needle is inserted, remove the hand that you used to pinch your skin. Use it to hold the syringe barrel.
• Pull the plunger of the syringe back very slightly.
• If no blood is present in the syringe, inject the medicine by gently pressing the plunger all the way down the syringe barrel, until the syringe is empty.
• If blood comes into the syringe, the needle has entered a blood vessel. Do not inject.
  • Withdraw the needle and throw away the syringe and needle in the puncture-proof container. (See step 24 and the disposal steps below.)
  • Then, repeat steps 1 through 23 with a new vial of PegIntron and diluent to prepare a new syringe, and inject the medicine at a new site.

24. When the syringe is empty, pull the needle out of the skin.

• Place a cotton ball or gauze over the injection site and press for several seconds. Do not massage the injection site.
• If there is bleeding, cover it with a bandage.
  

25. After injecting your dose:

• Firmly grasp the safety sleeve and pull it over the exposed needle until you hear a click, and the green stripe on the safety sleeve covers the red stripe on the needle (see Figure 19).

(Graphic Omitted)

26. Throw away the used syringe, needle, and vials in the puncture-proof disposable container. (See “How should I dispose of the used syringes, needles, and vials?”)

How should I dispose of the used syringes, needles, and vials?

• Throw away used syringes, needles, and vials in a puncture-proof container, sharps container, or a hard container like a metal can with a lid. Always place needles facing down. Do not use glass or clear plastic containers. Always keep the puncture-proof container out of the reach of children.
• Do not throw away used needles, syringes, or the puncture-proof container in household trash and do not recycle them.
• Check with your healthcare provider for instructions about the right way to throw away used needles and syringes. There may be local or state laws about how to throw away used needles and syringes. Always follow the instructions of your healthcare provider.

How should I store PegIntron?

• Before mixing, store PegIntron vials at room temperature, between 59°F to 86°F (15°C to 30°C).
• After mixing, use PegIntron right away or store it in the refrigerator for up to 24 hours between 36°F to 46°F (2°C to 8°C).
• Do not freeze PegIntron.
• Keep PegIntron away from heat.
• Keep PegIntron and all medicines out of the reach of children.

Manufactured by: Schering Corporation, a subsidiary of Merck & Co., Inc., Whitehouse Station, NJ 08889, USA.

Copyright © 2001, 2008 Schering Corporation, a subsidiary of Merck & Co., Inc. All rights reserved

Rev February/2011

35038906T

Instructions for Use

PegIntron ® (peg-In-tron)

(Peginterferon alfa-2b)

Solution for Injection REDIPEN

How to Use the PegIntron® REDIPEN® Single-dose Delivery System.

Be sure that you read, understand, and follow these instructions before injecting PegIntron Solution. Your healthcare provider should show you how to prepare, measure, and inject PegIntron properly before you use it for the first time. Ask your healthcare provider if you have any questions.

Before starting, collect all of the supplies that you will need to use for preparing and injecting PegIntron. For each injection you will need a PegIntron REDIPEN package that contains:

• the PegIntron REDIPEN single-dose delivery system
• 1 disposable needle
• 2 alcohol swabs
• dosing tray (the dosing tray is the bottom half of the REDIPEN package)
• You will need gauze or a cotton ball to press to the injection site after injecting. You will also need a puncture-proof disposable container to throw away your used REDIPEN.

Important:

• Never re-use needles.
• Make sure that you have the correct PegIntron REDIPEN prescribed by your healthcare provider. The PegIntron REDIPEN system is for a single use, by one person only, 1 time a week. The REDIPEN must not be shared.

The PegIntron REDIPEN should only be used with the injection needle that is provided in the packaging for the PegIntron REDIPEN system. If you use other needles, the pen may not work the right way.

• Figures 1 and 2 below show the different parts of the PegIntron REDIPEN Delivery System and the injection needle. Figure 3 below shows the dosing tray with the REDIPEN. The parts of the pen you need to know are:

(Graphic Omitted)

How should I prepare a dose of PegIntron using the REDIPEN?

1. Find a clean, well-lit, flat work surface.

2. Take the PegIntron REDIPEN out of the refrigerator and allow the medicine to come to room temperature. Look at the date printed on the PegIntron REDIPEN carton to make sure that the expiration date has not passed. Do not use if the expiration date has passed.

3. After taking the PegIntron REDIPEN out of the carton, look in the window of the REDIPEN and make sure the PegIntron in the cartridge holder window is a white to off-white tablet that is whole, or in pieces, or powdered.

4. Wash your hands well with soap and water. It is important to keep your work area, your hands, and the injection site clean to decrease the risk of infection (see Figure 4).

(Graphic Omitted)

Mix the Drug

5. Place the PegIntron REDIPEN upright in the dosing tray on a hard, flat, non-slip surface with the dosing button down (see Figure 5). You may want to hold the REDIPEN using the grip.

(Graphic Omitted)

6. To mix the powder and the liquid, keep the REDIPEN upright in the dosing tray and press the top half of the REDIPEN downward toward the hard, flat, non-slip surface until you hear the “click” sound (see Figure 6). When you hear the click, you will notice in the window that both dark stoppers are now touching. The dosing button should be flat with the pen body.

(Graphic Omitted)

7. Wait several seconds for the powder to completely dissolve.Do not shake. If the solution does not dissolve, gently turn the PegIntron REDIPEN upside down two times (see Figure 7).

(Graphic Omitted)

8. Keep the PegIntron REDIPEN UPRIGHT, with the dosing button down. Look through the REDIPEN window to see that the mixed PegIntron solution is completely dissolved. The solution should be clear and colorless before use. It is normal to see some small bubbles in the REDIPEN window, near the top of the solution. Do not use the PegIntron REDIPEN solution if it is discolored, or not clear, or if it has particles in it.

9. Place the PegIntron REDIPEN back into the dosing tray provided in the packaging (see Figure 8). The dosing button will be on the bottom.

(Graphic Omitted)

Attach the Needle

10. Before you attach the needle to the PegIntron REDIPEN, wipe the rubber membrane of the PegIntron REDIPEN with an alcohol swab.

11. Remove the protective paper tab from the injection needle, but do not remove either the outer cap or the yellow inner cap from the injection needle.

12. Keep the PegIntron REDIPEN upright in the dosing tray and push the injection needle straight into the REDIPEN rubber membrane. Screw the needle onto the PegIntron REDIPEN by turning it in a clockwise direction (see Figure 9).

• Remember to leave the needle caps in place when you attach the needle to the REDIPEN. Pushing the needle through the rubber membrane "primes" the needle and allows the extra liquid and air in the pen to be removed.

(Graphic Omitted)

NOTE: Some fluid will trickle out. This is normal. The dark stoppers move up and you will no longer see the fluid in the window once the needle is successfully primed.

• Remove the outer clear needle cap on the REDIPEN, but leave the yellow cap on (see Figure 10).

(Graphic Omitted)

How should I set the dose prescribed by my healthcare provider?

Dial the Dose

13. Holding the PegIntron REDIPEN firmly, pull the dosing button out as far as it will go (see Figure 11). You will see a dark band.

Do not push the dosing button in until you are ready to self-inject the PegIntron dose.

(Graphic Omitted)

14. Turn the dosing button until your prescribed dose is lined up with the dosing tab (see Figure 12). The dosing button will turn freely. If you have trouble dialing your dose, check to make sure the dosing button has been pulled out as far as it will go (see Figure 13).

(Graphic Omitted)

15. Carefully lay the PegIntron REDIPEN down on the dosing tray or on a hard, flat, non-slip surface. Do not remove the yellow needle cap and do not push the dosing button in until you are ready to self-inject the PegIntron dose.

Choosing an Injection Site

The best sites for giving yourself an injection are those areas with a layer of fat between the skin and muscle, like your thigh, the outer surface of your upper arm, and abdomen (see Figure 14). Do not inject yourself in the area near your navel or waistline. If you are very thin, you should only use the thigh or outer surface of the arm for injection.

(Graphic Omitted)

You should use a different site each time you inject PegIntron to avoid soreness at any one site. Do not inject PegIntron into an area where the skin is irritated, red, bruised, infected, or has scars, stretch marks, or lumps.

How should I Inject a dose of PegIntron?

16. Clean the skin where the injection is to be given with the second alcohol swab provided, and wait for the skin to dry.

17. There may be some liquid around the yellow inner needle cap (see Figure 15). This is normal.

(Graphic Omitted)

18. Remove the yellow inner needle cap when the injection site is dry (see Figure 16). You are now ready to inject.

(Graphic Omitted)

19. Hold the PegIntron REDIPEN with your fingers wrapped around the pen body barrel and your thumb on the dosing button (see Figure 17).

(Graphic Omitted)

20. With your other hand, pinch the skin in the area you have cleaned for injection.

21. Insert the needle into the pinched skin at an angle of 45° to 90° (see Figure 18)

(Graphic Omitted)

22. Press the dosing button down slowly and firmly until you can not push it any further. Keep your thumb pressed down on the dosing button for an additional 5 seconds to make sure that you get the complete dose.

23. Slowly release the dosing button and remove the needle from your skin.

24. Gently press the injection site with a small bandage or sterile gauze if needed for a few seconds but do not massage the injection site. If there is bleeding, cover with an adhesive bandage. Do not recap the needle and do not reuse the REDIPEN.

How do I dispose of the REDIPEN?

• Throw away the REDIPEN and needle and any solution remaining in the REDIPEN in a puncture-proof container, sharps container, or a hard container like a metal can with a lid. Always place needles facing down. Do not use glass or clear plastic containers. Always keep the puncture-proof container out of reach of children.
• Do not throw away used REDIPENS and needles in household trash and do not recycle them.
• Check with your healthcare provider for instructions about the right way to throw away used REDIPENS and needles. There may be local or state laws about how to throw away used REDIPENS and needles. Always follow the instructions of your healthcare provider.

How should I store PegIntron?

• Before mixing, store PegIntron REDIPEN in the refrigerator between 36°F to 46°F (2°C to 8°C).
• After mixing, use PegIntron right away or store it in the refrigerator for up to 24 hours between 36°F to 46°F (2°C to 8°C).
• Do not freeze PegIntron.
• Keep PegIntron away from heat.
• Keep PegIntron and all medicines out of the reach of children.

Manufactured by: Schering Corporation, a subsidiary of Merck & Co., Inc., Whitehouse Station, NJ 08889, USA.

Copyright © 2001, 2008 Schering Corporation, a subsidiary of Merck & Co., Inc. All rights reserved

Rev February/2011

35038809T