ImmunoGen, Inc. Announces First Clinical Findings with Refined Dosing Strategy for IMGN853

  • Initial Findings Show New Dosing Approach for IMGN853 Achieves Objective
  • Data Presented at American Association for Cancer Research Annual Meeting

Business Wire


ImmunoGen, Inc. (IMGN), a biotechnology company that develops novel anticancer therapeutics using its antibody-drug conjugate (ADC) technology, today announced the first findings from Company research aimed at optimizing the dosing of its IMGN853 product candidate. The data were presented at the American Association for Cancer Research (AACR) Annual Meeting in San Diego, CA.

Based on findings in the first patients to receive IMGN853, ImmunoGen identified that clinical activity is seen with the compound starting at doses of 3.3 mg/kg and its dose-limiting toxicity is the reversible ocular side effects (blurred vision and keratitis) reported with ADCs in development by several companies. These side effects occurred at IMGN853 doses of 5 mg/kg and above, with dose based on patient total body weight (TBW).

As presented today, modeling research conducted by ImmunoGen predicted that dosing IMGN853 using adjusted ideal body weight (ADJ) rather than TBW should reduce the variability among patients in the concentration of IMGN853 in their blood, as ADJ would better match the dose administered to patient blood volume. Reducing this variability should enable IMGN853 to be well tolerated in more patients at dose levels greater than 3.3 mg/kg. Based on these insights, dosing in the ongoing IMGN853 Phase 1 trial was changed to ADJ several months ago, and the first findings were reported today.

The clinical findings to date validate the prediction: none (0 of 6) of the patients treated with IMGN853 at 5 mg/kg ADJ have had ocular side effects of any grade. This compares with 4 of 10 patients treated at 5 mg/kg TBW. IMGN853 dose escalation above 5 mg/kg ADJ is ongoing.

“ImmunoGen is committed to successfully developing novel drugs that make a difference for people with cancer,” said Dr. Charles Morris, ImmunoGen Executive Vice President and Chief Development Officer. “Key to drug development is establishing the dosing strategy that provides the greatest efficacy with the least toxicity for each compound, and we believe the findings reported today reflect a strong path forward for IMGN853. We look forward to sharing additional IMGN853 clinical data in the months ahead.”

ImmunoGen also identified that dosing IMGN853 with a modified weekly schedule – weekly for three weeks every four weeks – should maximize tumor exposure to the compound while keeping IMGN853 blood levels in well-tolerated ranges. This dosing schedule, also using ADJ, has been added to the IMGN853 Phase 1 trial, but patient enrollment started too recently for findings to be available by AACR.

IMGN853 is in Phase I clinical testing for the treatment of folate receptor α (FRα)-positive cancers. The Company is currently establishing the maximum tolerated dose (MTD) of IMGN853 when administered once every three weeks using ADJ. Once this MTD is established, IMGN853 will be evaluated at that dose specifically in patients with platinum-resistant ovarian cancer and in patients with relapsed endometrial cancer. The Company is now also establishing its MTD with the modified weekly schedule.

About IMGN853

IMGN853, an ADC, is a potential new treatment for ovarian, endometrial, lung and other cancers that highly express FRα. It comprises an ImmunoGen FRα-targeting antibody attached to the Company's potent cancer cell-killing agent, DM4. The antibody serves to target the compound specifically to cancer cells expressing FRα, and the DM4 serves to kill these cells.

About ImmunoGen, Inc.

ImmunoGen, Inc. develops targeted anticancer therapeutics. The Company’s ADC technology uses tumor-targeting antibodies to deliver an ImmunoGen cell-killing agent specifically to cancer cells; the Company has also developed antibodies with anticancer activity of their own. The first product approved with ImmunoGen’s ADC technology is Roche’s Kadcyla®. ImmunoGen has three wholly owned product candidates in clinical testing, with seven additional compounds in the clinic through the Company’s partnerships with Amgen, Bayer HealthCare, Biotest and Sanofi. More information about ImmunoGen can be found at

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

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 IMGN853. A review of these risks can be found in ImmunoGen's Annual Report on Form 10-K for the fiscal year ended June 30, 2013 and other reports filed with the Securities and Exchange Commission.

For Investors:
ImmunoGen, Inc.
Carol Hausner, 781-895-0600
For Media:
Pure Communications, Inc.
Dan Budwick, 973-271-6085
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