ImmunoGen to Present New Data on Novel Antibody-Drug Conjugates at 59th ASH Annual Meeting

WALTHAM, Mass.--()--ImmunoGen, Inc. (Nasdaq: IMGN), a leader in the expanding field of antibody-drug conjugates (ADCs) for the treatment of cancer, today announced that three abstracts highlighting two of the Company’s experimental ADC therapies, IMGN632 and IMGN779, have been accepted for presentations at the upcoming American Society of Hematology (ASH) Annual Meeting to be held December 9-12, 2017, in San Diego.

Both IMGN779 and IMGN632 use ImmunoGen's novel indolino-benzodiazepine payloads called IGNs, which alkylate DNA without crosslinking. IMGN779 is a CD33-targeted ADC for the treatment of acute myeloid leukemia (AML) currently in Phase 1 testing. IMGN632 is a CD123-targeted ADC for hematological malignancies, including AML and blastic plasmacytoid dendritic cell neoplasm (BPDCN). Last month, the Company announced that the Investigational New Drug application for IMGN632 is active and it expects to open a Phase 1 trial later this year.

“The clinical and preclinical data being presented at ASH demonstrate the early potential of our novel IGN portfolio,” said Richard Gregory, Ph.D., executive vice president and chief scientific officer of ImmunoGen. “One of our strategic priorities is to accelerate the development of these unique and highly differentiated assets. IMGN779 and IMGN632 use our IGN payloads, which were designed to meet the dual challenges of achieving high potency against target cells, while having a tolerability profile that enables continued patient treatment.”

In a poster presentation, the Company will report updated data evaluating the safety and anti-leukemia activity from the dose escalation phase of the IMGN779 first-in-human trial. In a separate presentation, preclinical data evaluating the mechanism, anti-leukemia efficacy, and tolerability of repeated dosing of IMGN779 and cytarabine in combination using in vitro and in vivo human AML preclinical models will be reported. Lastly, preclinical data reporting the prevalence of CD123 expression in acute lymphoblastic leukemia (ALL), and assessing the anti-leukemia activity of IMGN632 on ALL cells will be presented in a poster presentation.

Poster Presentations

  • Title (Abstract #1357): “IMGN779, a Next Generation CD33-Targeting ADC, Combines Effectively With Cytarabine in Acute Myeloid Leukemia (AML) Preclinical Models, Resulting in Increased DNA Damage Response, Cell Cycle Arrest and Apoptosis In Vitro, and Prolonged Survival In Vivo
    • Poster session #616: Saturday, December 9, 5:30 – 7:30 PM PST.
  • Title (Abstract #1312): “IMGN779, a Next-Generation CD33-Targeting Antibody-Drug Conjugate (ADC) Demonstrates Initial Antileukemia Activity in Patients with Relapsed or Refractory Acute Myeloid Leukemia”
    • Poster session #613: Saturday, December 9, 5:30 – 7:30 PM PST.
  • Title (Abstract #2718): “CD123 Expression Patterns and Potential of IMGN632, a CD123-Targeted Antibody Drug Conjugate, in Acute Lymphoblastic Leukemia”
    • Poster session #618: Sunday, December 10, 6:00 – 8:00 PM PST.

Additional information can be found at www.hematology.org, including abstracts.

About IMGN779
IMGN779 is a novel ADC that combines a high-affinity, humanized anti-CD33 antibody, a cleavable disulfide linker, and one of ImmunoGen’s novel indolino-benzodiazepine payloads, called IGNs, which alkylate DNA without crosslinking, resulting in potent preclinical anti-leukemia activity with relative sparing of normal hematopoietic progenitor cells.1,2 IMGN779 is in Phase 1 clinical testing for the treatment of AML.

About IMGN632
IMGN632 is a humanized anti-CD123 antibody-drug conjugate that is a potential treatment for AML, BPDCN, myelodysplastic syndrome, B-cell acute lymphocytic leukemia, and other CD123-positive malignancies. IMGN632 uses a novel IGN payload, linker and antibody technology and in AML xenograft models has demonstrated a large therapeutic index.3

About IGNs
Indolino-benzodiazepine cancer-killing agents, or IGNs, are a new class of cancer-killing agent developed by ImmunoGen for use in ADCs. These ultra-potent, DNA-acting IGNs alkylate DNA without crosslinking, which preclinically has resulted in potent anti-leukemia activity with relative sparing of normal hematopoietic progenitor cells.4,5 IMGN779, a CD33-targeting ADC in Phase 1 testing for AML, was the first IGN ADC to enter clinical testing.

About Acute Myeloid Leukemia (AML)
AML is a cancer of the bone marrow cells that produce white blood cells. It causes the marrow to increasingly generate abnormal, immature white blood cells (blasts) that do not mature into effective infection-fighting cells. The blasts quickly fill the bone marrow, impacting the production of normal platelets and red blood cells. The resulting deficiencies in normal blood cells leave the patient vulnerable to infections, bleeding problems and anemia.

It is estimated that, in the U.S. alone, 21,380 patients will be diagnosed with AML this year and 10,590 patients will die from the disease.6

About ImmunoGen, Inc.
ImmunoGen is a clinical-stage biotechnology company that develops targeted cancer therapeutics using its proprietary ADC technology. The Company’s lead product candidate, mirvetuximab soravtansine, is in a Phase 3 trial for FRα-positive platinum-resistant ovarian cancer, and is in a Phase 1b/2 trial in combination regimens for earlier-stage disease. ImmunoGen has three additional clinical-stage product candidates, two of which are being developed in collaboration with Jazz Pharmaceuticals. ImmunoGen's ADC technology is also used in Roche's marketed product, Kadcyla®, and in programs in development by Amgen, Bayer, Biotest, CytomX, Debiopharm, Lilly, Novartis, Sanofi and Takeda. More information about the Company can be found at www.immunogen.com.

Kadcyla® is a registered trademark of Genentech, a member of the Roche Group.

S. Adams et al, Abstract P526, Presented at the 22nd Congress of the European Hematology Association, June 22-25, 2017.
Y. Kotvun et al. (2016) Blood 128:768.
S. Adams et al, Abstract 2832, Presented at the American Society of Hematology, December 3-6, 2016.
S. Adams et al, 2017.
Y. Kotvun, 2016.
6American Cancer Society (2016), About Acute Myeloid Leukemia.

This press release includes forward-looking statements. For these statements, ImmunoGen claims the protection of the safe harbor for forward-looking statements provided by the Private Securities Litigation Reform Act of 1995. It should be noted that there are risks and uncertainties related to the development of novel anticancer products, including IMGN779 and IMGN632, including risks related to preclinical and clinical studies, their timings and results. A review of these risks can be found in ImmunoGen's Transition Report on Form 10-KT for the six-month transition period ended December 31, 2016 and other reports filed with the Securities and Exchange Commission.

Contacts

For Investors
ImmunoGen, Inc.
Sarah Kiely, 781-895-0600
sarah.kiely@immunogen.com
or
For Media
ImmunoGen, Inc.
Courtney O'Konek, 781-895-0600
courtney.okonek@immunogen.com
or
Robert Stanislaro
FTI Consulting, Inc., 212-850-5657
robert.stanislaro@fticonsulting.com

Contacts

For Investors
ImmunoGen, Inc.
Sarah Kiely, 781-895-0600
sarah.kiely@immunogen.com
or
For Media
ImmunoGen, Inc.
Courtney O'Konek, 781-895-0600
courtney.okonek@immunogen.com
or
Robert Stanislaro
FTI Consulting, Inc., 212-850-5657
robert.stanislaro@fticonsulting.com