ImmunoGen, Inc. (Nasdaq: IMGN), a biopharmaceutical company that develops anticancer therapeutics using its antibody expertise and Targeted Antibody Payload (TAP) technology, today announced the presentation of clinical data for the Company’s IMGN901 targeted anticancer compound at the Chicago Multidisciplinary Symposium in Thoracic Oncology. “The data being reported today are from the dose-finding evaluation conducted to establish the recommended Phase II dose for our NORTH trial,” commented James O’Leary, MD, Vice President and Chief Medical Officer. “IMGN901 was able to be administered in combination with a standard etoposide/carboplatin regimen at its full single-agent dose, which speaks to the favorable tolerability profile of this compound. Additionally, while enrollment wasn’t limited to patients with SCLC, the findings seen in those patients are encouraging.” The Dose-Finding Evaluation Conducted This Phase I assessment was designed to establish the dose of IMGN901 to be used in combination with etoposide (E) and carboplatin (C) in a Phase II assessment – the NORTH trial – of this combination regimen for the first-line treatment of SCLC. E/C is a standard treatment for newly diagnosed, extensive disease SCLC, and the NORTH trial is designed to assess whether adding IMGN901 to E/C provides a meaningful additional clinical benefit. In this assessment, IMGN901 is administered on Days 1 and 8 every 21 days. Enrollment in the dose-finding evaluation was open to patients with any type of advanced solid tumors appropriately treated with E/C. All patients received E at its standard dose of 100 mg/m 2, given on Days 1-3 every 21 days. Two different doses of C are widely used with E – C AUC5 and C AUC6 – and thus escalating doses of IMGN901 were evaluated with each. C is administered on Day 1 every 21 days. A total of 33 patients received one of the five dose combinations assessed (two alternative IMGN901 doses with C AUC6 and three with C AUC5). Thirteen of these patients had SCLC. Phase II Dose Established The Phase II dose established was IMGN901 at 112 mg/m 2 with C AUC5 and E at 100 mg/m 2. Higher IMGN901 doses were not evaluated as 112 mg/m 2 was the maximum tolerated dose established in an assessment of IMGN901 given as a single agent in another trial with the D1, D8 every 21 days dosing schedule. The overall safety profile of IMGN901 used with C/E was consistent with that of IMGN901 and of C/E used separately. Low grade (1 or 2) peripheral neuropathy was the most common adverse event considered by the investigators to be related to the treatment regimen, as reported previously for IMGN901, while myelosuppressive events were the most common related grade 3 or 4 events, as reported previously for C/E.