Safety, pharmacology, and preliminary clinical activity of MM-151: An oligocolnal anti-EGFR theraputic in patients with cetuximab-resistant CRC and other refractory solid tumors.

647 Background: MM-151 is an oligoclonal anti-EGFR antibody combination designed to provide enhanced targeting of the EGFR network. This work describes the first in human experience of MM-151 alone and in combination with irinotecan. Methods: A standard 3+3 design was used to assess safety and tolerability of MM-151 monotherapy (QW, Q2W, Q3W) and MM-151 (QW) in combination with irinotecan 180mg/m2 (Q2W). A monotherapy expansion cohort has begun in cetuximab-resistant CRC. Results: Results presented are based on preliminary data as of September 2, 2014, for MM-151 monotherapy (n=65; QW/Q2W) and MM-151 in combination with irinotecan (n=10). The most common tumor types were CRC (29 [39%]), NSCLC (9 [12%]), HNSCC (8 [11%]). The monotherapy RP2D has been defined as 10.5 mg/kg QW and dosing continues at 18 mg/kg Q2W. Most adverse events were CTCAE grades 1 and 2. The most common AEs were toxicities related to the EGFR-pathway, including rash (70%), hypomagnesemia (24%), fatigue, dry skin, and diarrhea (21%). IR...