Genentech has initiated Phase II testing of trastuzumab-DM1 in HER2-expressing metastatic breast cancer, triggering a $5-million milestone payment to Immunogen. The product comprises ImmunoGen's cell-killing agent, DM1, linked to Genentech's HER2-targeting antibody, trastuzumab.
The 2000 transaction between the companies gave Genentech exclusive rights to develop candidates using ImmunoGen's maytansinoid Tumor-Activated Prodrug (TAP) technology and linkers with therapeutic antibodies to HER2. In 2006, the agreement was amended such that ImmunoGen would earn increased milestone payments. Genentech is responsible for product development, manufacturing, and commercialization.
ImmunoGen created its TAP technology to enhance the anticancer activity of tumor-targeting mAbs. The tool attaches one of its cell-killing agents, DM1 or DM4, to an anticancer antibody using a linker.