SAR3419 is in Phase I clinical testing for the treatment of non-Hodgkin's lymphoma. This cancer is the most commonly diagnosed type of liquid tumor in the US today.

We licensed SAR3419 to sanofi-aventis when it was in preclinical research. It consists of a CD19-binding antibody (created and humanized by ImmunoGen) with our DM4 payload attached using one of our engineered linkers.

The first SAR3419 clinical data were presented at the American Society of Hematology (ASH) annual meeting in December 2009. These data were from a Phase I dose-escalation trial in which new cohorts of patients received increasingly higher doses of SAR3419 until its maximum tolerated dose was established. In this trial, the compound was administered once every three weeks and the maximum number of doses patients could receive was restricted to six.

Another Phase I study is underway evaluating SAR3419 when dosed on a weekly basis. ImmunoGen expects findings from that trial to be reported in 2010.