ImmunoGen gains on T-DM1 data

ImmunoGen Inc. (NASDAQ:IMGN) gained $0.40 to $7.10 on Friday after reporting data from the Phase II TDM4450g of trastuzumab-DM1 ( T-DM1) for the first-line treatment of HER2-positive metastatic breast cancer. T-DM1 every three weeks produced an overall response rate (ORR) of 48%, including three complete responses and 29 partial responses, plus 22 cases of stable disease. The active-control arm consisting of Herceptin trastuzumab plus Taxotere docetaxel produced an ORR of 41%, including 1 complete response and 28 partial responses, plus 29 cases of stable disease. Clinical benefit rate, defined as complete response, partial response and stable disease of more than 6 months, was 55.2% for T-DM1 vs. 57.1% for Herceptin plus Taxotere. The open-label, international trial enrolled 137 treatment-naive patients. Data will be presented at the European Society for Medical Oncology meeting in Milan on Monday.

In August, FDA refused to file a BLA requesting accelerated approval for T-DM1 for third-line advanced HER2-positive breast cancer. FDA said T-DM1 trials did not meet the standard for accelerated approval because all available treatments approved for metastatic breast cancer, regardless of HER2 status, had not been exhausted in the study population. T-DM1 is a humanized mAb against epidermal growth factor (EGF) receptor 2 (HER2) linked to ImmunoGen's DM1 cytotoxic agent. ...