PD-0024 Phase I/II Study of Folfiri Plus the MEK1/2 Inhibitor Pimasertib (MSC1936369B) as Second-Line Treatment for KRAS Mutated Metastatic Colorectal Cancer

ABSTRACT Introduction Pimasertib is a highly selective inhibitor of the MEK1/2 kinases of the MAPK pathway. It demonstrates potent antitumor activity in cell lines and xenograft models with activating (mainly BRAF and KRAS) mutations. A two-part study, comprising a safety run-in part followed by a randomized phase II part, was designed to investigate FOLFIRI plus pimasertib as second-line treatment for patients with KRAS mutated (mt) metastatic colorectal cancer (mCRC). The results of the safety run-in part, conducted primarily to determine the maximum tolerated dose (MTD) and the recommended phase II dose (RP2D), are reported here. Methods Patients with KRAS mt mCRC progressing on first-li…