Merck will evaluate Keytruda cancer combo therapy

Merck and Syndax pharmaceuticals entered into a clinical trial collaboration Tuesday. The duo will pair Merck's Keytruda with Syndax's entinostat in patients with advanced non-small cell lung cancer and melanoma. They expect to begin enrolling patients in a Phase-Ib/2 study in the second half of 2015.

The Phase-Ib trial will evaluate the safety profile of the two combined drugs, while the Phase-II trial will look to determine the efficacy of the pairing in lung and skin cancers. The agreement includes the possibility of extending the collaboration for a potential Phase-III study.

Keytruda was the first US-approved anti-PD-1 therapy. It is currently indicated as a second- and third-line treatment for patients with advanced metastatic melanoma. An independent data monitoring committee halted a Keytruda trial last week that was seeking to measure patients' progression-free survival compared to those treated with Bristol-Myers Squibb's Yervoy.

Entinostat is an HDAC inhibitor. It was granted Breakthrough Therapy designation in September 2013 for treatment of metastatic ER+ breast cancer.