Seattle Genetics Submits Supplemental BLA to FDA for Retreatment and Extended Duration of Therapy with ADCETRIS® (Brentuximab Vedotin) in Relapsed Hodgkin Lymphoma and Systemic ALCL

BOTHELL, Wash.--()--Seattle Genetics, Inc. (Nasdaq: SGEN) announced today that it has submitted a supplemental Biologics License Application (sBLA) to the U.S. Food and Drug Administration (FDA) supporting the use of ADCETRIS (brentuximab vedotin) for retreatment and extended duration beyond 16 cycles of therapy in relapsed Hodgkin lymphoma (HL) and systemic anaplastic large cell lymphoma (sALCL). ADCETRIS is an antibody-drug conjugate (ADC) directed to CD30, a defining marker of HL and sALCL, that was granted accelerated approval by the FDA in August 2011 for relapsed HL and relapsed sALCL.

“The sBLA submission includes data demonstrating ADCETRIS activity in managing HL and sALCL when used in the retreatment setting, as well as beyond the 16 cycles described in our current label, while retaining a manageable safety profile,” said Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. “Our goal is to broaden the ADCETRIS U.S. labeling claims to provide both patients and physicians the opportunity to incorporate ADCETRIS into additional HL and sALCL treatment settings. The sBLA submission includes data that support these uses and we look forward to the regulatory outcome.”

The sBLA is based on results from a phase II clinical trial with two treatment arms. One arm evaluated retreatment with ADCETRIS in patients who previously responded to treatment with ADCETRIS, then discontinued treatment and subsequently had disease progression or relapse. The other arm allowed treatment extension and evaluated prolonged treatment with ADCETRIS beyond 16 cycles of therapy. The sBLA submission includes updated data sets from this phase II trial. Preliminary data from this trial were previously reported at the 2011 American Society of Hematology (ASH) Annual Meeting and at the 2012 American Society of Clinical Oncology (ASCO) Annual meeting.

At the 2012 ASCO Annual Meeting, retreatment data from the phase II trial were reported from 23 patients, including one patient who was treated twice. Patients had received a median of four prior systemic therapies, including ADCETRIS. Of 23 evaluable patients, 70 percent (16 of 23) achieved an objective response after retreatment with ADCETRIS, including nine complete remissions and seven partial remissions. Median duration of retreatment objective response was 8.8 months. Among retreated HL patients, nine of 16 (56 percent) achieved an objective response. Among retreated sALCL patients, seven of eight (88 percent) achieved an objective response. The most common adverse events were peripheral neuropathy (46 percent), nausea (42 percent), fatigue (38 percent), diarrhea (33 percent) and fever (29 percent).

At the 2011 ASH Annual Meeting, prolonged treatment data were reported from 17 patients with a median duration of treatment of 17.3 months (approximately 24 cycles of every three week dosing). The overall objective response rate with extended treatment was 88 percent, including 76 percent complete remissions and 12 percent partial remissions. ADCETRIS was generally well-tolerated, with the most common adverse events being peripheral neuropathy (71 percent), upper respiratory infection (53 percent) and fatigue (47 percent). Prolonged treatment with ADCETRIS was associated with clinically meaningful durations of response without worsening of toxicity over time.

ADCETRIS is currently not approved for retreatment and extended duration beyond 16 cycles of therapy in relapsed HL and sALCL.

About Lymphoma

Lymphoma is a general term for a group of cancers that originate in the lymphatic system. There are two major categories of lymphoma: Hodgkin lymphoma and non-Hodgkin lymphoma. Hodgkin lymphoma is distinguished from other types of lymphoma by the presence of one characteristic type of cell, known as the Reed-Sternberg cell. The Reed-Sternberg cell generally expresses CD30. Systemic ALCL is an aggressive type of T-cell non-Hodgkin lymphoma that also expresses CD30.

About ADCETRIS

ADCETRIS (brentuximab vedotin) is an ADC comprising an anti-CD30 monoclonal antibody attached by a protease-cleavable linker to a microtubule disrupting agent, monomethyl auristatin E (MMAE), utilizing Seattle Genetics’ proprietary technology. The ADC employs a linker system that is designed to be stable in the bloodstream but to release MMAE upon internalization into CD30-expressing tumor cells.

ADCETRIS was granted accelerated approval by the FDA in August 2011 and approval with conditions by Health Canada in February 2013 for two indications: (1) the treatment of patients with HL after failure of autologous stem cell transplant (ASCT) or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates, and (2) the treatment of patients with sALCL after failure of at least one prior multi-agent chemotherapy regimen. The indications for ADCETRIS are based on response rate. There are no data available demonstrating improvement in patient-reported outcomes or survival with ADCETRIS.

ADCETRIS was granted conditional marketing authorization by the European Commission in October 2012 for the treatment of adult patients with relapsed or refractory CD30+ Hodgkin lymphoma (HL): (1) following autologous stem cell transplant (ASCT), or (2) following at least two prior therapies when ASCT or multi-agent chemotherapy is not a treatment option. ADCETRIS is indicated for the treatment of adult patients with relapsed or refractory sALCL. See important safety information below.

Seattle Genetics and Millennium are jointly developing ADCETRIS. Under the terms of the collaboration agreement, Seattle Genetics has U.S. and Canadian commercialization rights and the Takeda Group has rights to commercialize ADCETRIS in the rest of the world. Seattle Genetics and the Takeda Group are funding joint development costs for ADCETRIS on a 50:50 basis, except in Japan where the Takeda Group is solely responsible for development costs.

About Seattle Genetics

Seattle Genetics is a biotechnology company focused on the development and commercialization of monoclonal antibody-based therapies for the treatment of cancer. The company’s lead program, ADCETRIS (brentuximab vedotin), received accelerated approval from the U.S. Food and Drug Administration in August 2011 and approval with conditions from Health Canada in February 2013 for two indications. In addition, under a collaboration with Millennium: The Takeda Oncology Company, ADCETRIS received conditional approval from the European Commission in October 2012. Seattle Genetics also has four other clinical-stage ADC programs: SGN-75, ASG-5ME, ASG-22ME and SGN-CD19A. Seattle Genetics has collaborations for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including AbbVie (formerly Abbott), Agensys (an affiliate of Astellas), Bayer, Celldex Therapeutics, Daiichi Sankyo, Genentech, GlaxoSmithKline, Millennium, Pfizer and Progenics, as well as ADC co-development agreements with Agensys and Genmab. More information can be found at www.seattlegenetics.com.

U.S. Important Safety Information

BOXED WARNING

Progressive multifocal leukoencephalopathy (PML): JC virus infection resulting in PML and death can occur in patients receiving ADCETRIS.

Contraindication:

Concomitant use of ADCETRIS and bleomycin is contraindicated due to pulmonary toxicity.

Warnings and Precautions:

  • Peripheral neuropathy: ADCETRIS treatment causes a peripheral neuropathy that is predominantly sensory. Cases of peripheral motor neuropathy have also been reported. ADCETRIS-induced peripheral neuropathy is cumulative. Treating physicians should monitor patients for symptoms of neuropathy, such as hypoesthesia, hyperesthesia, paresthesia, discomfort, a burning sensation, neuropathic pain or weakness and institute dose modifications accordingly.
  • Infusion reactions: Infusion-related reactions, including anaphylaxis, have occurred with ADCETRIS. Monitor patients during infusion. If an infusion reaction occurs, the infusion should be interrupted and appropriate medical management instituted. If anaphylaxis occurs, the infusion should be immediately and permanently discontinued and appropriate medical management instituted.
  • Neutropenia: Monitor complete blood counts prior to each dose of ADCETRIS and consider more frequent monitoring for patients with Grade 3 or 4 neutropenia. If Grade 3 or 4 neutropenia develops, manage by dose delays, reductions or discontinuation. Prolonged (≥1 week) severe neutropenia can occur with ADCETRIS.
  • Tumor lysis syndrome: Patients with rapidly proliferating tumor and high tumor burden are at risk of tumor lysis syndrome and these patients should be monitored closely and appropriate measures taken.
  • Progressive multifocal leukoencephalopathy (PML): JC virus infection resulting in PML and death has been reported in ADCETRIS-treated patients. In addition to ADCETRIS therapy, other possible contributory factors include prior therapies and underlying disease that may cause immunosuppression. Consider the diagnosis of PML in any patient presenting with new-onset signs and symptoms of central nervous system abnormalities. Evaluation of PML includes, but is not limited to, consultation with a neurologist, brain MRI, and lumbar puncture or brain biopsy. Hold ADCETRIS if PML is suspected and discontinue ADCETRIS if PML is confirmed.
  • Stevens-Johnson syndrome: Stevens-Johnson syndrome has been reported with ADCETRIS. If Stevens-Johnson syndrome occurs, discontinue ADCETRIS and administer appropriate medical therapy.
  • Use in pregnancy: Fetal harm can occur. Pregnant women should be advised of the potential hazard to the fetus.

Adverse Reactions:

ADCETRIS was studied as monotherapy in 160 patients in two phase 2 trials. Across both trials, the most common adverse reactions (≥20%), regardless of causality, were neutropenia, peripheral sensory neuropathy, fatigue, nausea, anemia, upper respiratory tract infection, diarrhea, pyrexia, rash, thrombocytopenia, cough and vomiting.

Drug Interactions:

Patients who are receiving strong CYP3A4 inhibitors concomitantly with ADCETRIS should be closely monitored for adverse reactions.

For additional important safety information, including Boxed WARNING, please see the full U.S. prescribing information for ADCETRIS at www.seattlegenetics.com or www.ADCETRIS.com.

Certain of the statements made in this press release are forward-looking, such as those, among others, relating to the company’s expectations for the addition of the label claims sought in the sBLA. Factors that may cause such a difference include that the submitted data are not sufficient to provide for approval of the claims in the sBLA. More information about the risks and uncertainties faced by Seattle Genetics is contained in the company’s Annual Report on Form 10-K for the year ended December 31, 2012 filed with the Securities and Exchange Commission. Seattle Genetics disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Contacts

Seattle Genetics, Inc.
Investors:
Peggy Pinkston, 425-527-4160
ppinkston@seagen.com
or
Media:
Tricia Larson, 425-527-4180
tlarson@seagen.com

Contacts

Seattle Genetics, Inc.
Investors:
Peggy Pinkston, 425-527-4160
ppinkston@seagen.com
or
Media:
Tricia Larson, 425-527-4180
tlarson@seagen.com