ImmunoGen Presents Updated Findings from Phase 1/2 Study of IMGN632 in Blastic Plasmacytoid Dendritic Cell Neoplasm at ASH Annual Meeting - Seite 2

• In all relapsed/refractory BPDCN patients, the overall response rate (ORR) was 29% (8/28) with a composite complete remission (CCR) rate of 18% (5/28).
• In patients with prior SL-401 exposure (tagraxofusp-erzs), the ORR was 31% (4/13) with a CCR of 15% (2/13).
• Among patients with bone marrow response assessment, 60% (9/15) achieved a bone marrow complete response (blasts <5%).
• Durable responses were seen in multiple patients, up to 9.2 months without hematopoietic stem cell transplant.
• Two patients have been successfully bridged to hematopoietic stem cell transplant.

TRIAL IN PROGRESS POSTER

Title: “A Phase 1b/2 Study of IMGN632, a CD123-Targeting Antibody-Drug Conjugate, As Monotherapy or in Combination with Venetoclax and/or Azacitidine for Patients with CD123-Positive Acute Myeloid Leukemia” (Abstract 1047)
Poster Session: 616
Date: Saturday, December 5, 2020
Time: 7:00am – 3:30pm PT/10:00am – 6:30pm ET

PRECLINICAL POSTER

In addition, our partners at MD Anderson Cancer Center will present preclinical data from their study combining IMGN632, venetoclax, and azacitidine in in vitro and in vivo AML models.

Title: “Combining IMGN632, a Novel CD123-Targeting Antibody Drug Conjugate with Azacitidine and Venetoclax Facilitates Apoptosis in Vitro and Prolongs Survival In Vivo in AML Models” (Abstract 2886)
Poster Session: 617
Date: Monday, December 7, 2020
Time: 7:00am – 3:30pm PT/10:00am – 6:30pm ET

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

CONFERENCE CALL INFORMATION

ImmunoGen will hold a conference call on Monday, December 7 at 8:00 a.m. ET to discuss the data presented at ASH, the pathway to FDA approval in BPDCN, and an AML program progress update; Dr. Naveen Pemmaraju, Associate Professor in the Department of Leukemia at MD Anderson Cancer Center, will join the call to review the BPDCN data presented at ASH. To access the live call by phone, dial [phone]; the conference ID is 1795760. The call, along with associated slides, may also be accessed through the Investors and Media section of immunogen.com. Following the call, a replay will be available at the same location.