Keytruda data show correlation with MMR biomarker

Merck and Co. Inc. (NYSE:MRK) announced the first clinical results showing a correlation of benefit from treatment with PD-1 inhibitor Keytruda pembrolizumab in patients with DNA mismatch repair (MMR) deficiency. In a Phase II trial, colorectal cancer (CRC) patients with MMR-deficient tumors had an objective response rate (ORR) of 62% vs. no responses among MMR-proficient patients.

Merck intends to begin a new registrational Phase II study, KEYNOTE-164, in mid-2015 to study Keytruda in CRC patients based on MMR status. ...