CAMBRIDGE, Mass.--(BUSINESS WIRE)--ImmunoGen, Inc. (Nasdaq: IMGN) today announced that sanofi-aventis has initiated clinical testing of AVE1642, a therapeutic antibody that binds to the Insulin-like Growth Factor 1 Receptor (IGF-1R). This event triggers a $2 million milestone payment to ImmunoGen. AVE1642 is an anticancer compound that was developed by ImmunoGen and licensed to sanofi-aventis as part of a broader collaboration between the companies.