ImmunoGen presents Phase I trial results of SAR650984 at ASH annual meeting

ImmunoGen, Inc. (NASDAQ: IMGN), a biotechnology company that develops targeted, antibody-based anticancer therapeutics, today announced the first clinical findings with SAR650984 reported in an oral presentation at the ASH annual meeting. The data are from an ongoing Phase I trial assessing this CD38-targeting therapeutic antibody in patients with CD38-positive MM or other hematologic malignancy. SAR650984 was initially developed by ImmunoGen with the Company's target evaluation and antibody development expertise and was licensed to Sanofi as part of a broader collaboration between the companies.

The findings reported today are from a Phase I trial designed to determine the maximum tolerated dose (MTD) and maximum administered dose of SAR650984, which is identified by administering increasing doses of the compound to new cohorts of patients until dose-limiting toxicity is reported. Secondary objectives of the trial include characterization of the compound's safety profile, assessing its pharmacokinetics, and identifying preliminary evidence of disease response.

SAR650984 was found to have a favorable safety profile. The most common treatment emergent adverse events (TEAEs), of any grade, were fatigue, nausea, pyrexia, cough, anemia, and headache. At the time of data cutoff for presentation, the highest dose evaluated was 20 mg/kg given over a two week period (10 mg/kg weekly or 20 mg/kg every two weeks) and the MTD had not been established. Infusion reactions were reported, and typically occurred during the first dose. These were managed with routine measures, with standard premedications required.

Twenty-four of the patients with MM enrolled in the trial received SAR650984 at or above a dose of 1 mg/kg every two weeks. All of these patients had received prior Revlimid^® (lenalidomide) and Velcade^® (bortezomib), most had previously been treated with Kyprolis^® (carfilzomib) and/or Pomalyst^® (pomalidomide), and many had received other prior therapies as well.

Response information was available for 22 of these 24 patients at the time of data cutoff for analysis, and was assessed by European Group for Blood and Marrow Transplantation (EBMT) criteria:

• Among these 22 patients, the best response to therapy reported was: 2 complete response (CR), 4 partial response (PR), 2 minimal response (MR), 9 stable disease (SD), and 5 progressive disease (PD).
• Among the 11 of these patients treated with a dose of 10 mg/kg or more, there were 2 CRs, 2 PRs, 1 MR, 4 SDs, and 2 PDs.
• Among the 8 patients with objective responses (CR, PR or MR), 6 were still on treatment at the time of data cutoff for presentation. Four of these patients had been on treatment for more than 26 weeks, and one had been on for over one year.

"It is impressive that so many objectives responses - including complete responses - were seen with SAR650984 when administered as a single agent to patients with such heavily pretreated multiple myeloma," commented John Lambert, PhD, ImmunoGen EVP and Chief Scientific Officer. "The SAR650984 antibody was selected for development because of its notable anticancer activity in preclinical models, particularly its pronounced ability to directly kill cancer cells through induction of apoptosis."