Array BioPharma Announces Collaboration with Merck for KEYTRUDA

BOULDER: Array BioPharma Inc. announced today that it has entered into a clinical trial collaboration agreement with Merck (known as MSD outside the United States and Canada) to investigate the safety and efficacy of Array's MEK inhibitor, binimetinib, with Merck's anti-PD-1 therapy, KEYTRUDA^® (pembrolizumab), in metastatic colorectal cancer patients with microsatellite stable tumors (MSS CRC).

The companies are entering into this collaboration based on the growing body of preclinical and clinical evidence that the immune activity of an anti-PD-1 therapy, such as KEYTRUDA, can be enhanced when combined with a MEK inhibitor, such as binimetinib.

Under the terms of the agreement, Array and Merck will collaborate on a clinical trial to investigate the safety and efficacy of the combination of binimetinib with KEYTRUDA, in MSS CRC patients. The trial is expected to establish a recommended dose regimen of binimetinib and KEYTRUDA, as well as explore the preliminary anti-tumor activity of several novel regimens. The study is expected to begin in the second half of 2017. Results from this first study will be used to determine optimal approaches to further clinical development of these combinations.

The collaboration agreement is between Array BioPharma and Merck, through a subsidiary. Under the agreement, the trial will be sponsored by Merck. Additional details of the collaboration were not disclosed.

About Colorectal Cancer
Worldwide, colorectal cancer is the third most common type of cancer in men and the second most common in women, with approximately 1.4 million new diagnoses in 2012. Of these, nearly 750,000 were diagnosed in men, and 614,000 in women. Globally in 2012, approximately 694,000 deaths were attributed to colorectal cancer. In the U.S. alone, an estimated 135,430 patients will be diagnosed with cancer of the colon or rectum in 2017, and approximately 50,000 are estimated to die of their disease. There is wide variation in 5-year survival rates across the globe, with 5-year survival expected to be around 65% in the developed world and dropping to around 20% in some developing countries. The incidence of microsatellite stability in colorectal tumors varies by stage, with nearly 80% of early stage, resectable tumors and approximately 67% of advanced, metastatic tumors exhibiting MSS.

About Binimetinib

MEK is a key protein kinase in the MAPK signaling pathway (RAS-RAF-MEK-ERK). Research has shown this pathway regulates several key cellular activities including proliferation, differentiation, survival and angiogenesis. Inappropriate activation of proteins in this pathway has been shown to occur in many cancers, such as melanoma, colorectal and thyroid cancers. Binimetinib is a late-stage small molecule MEK inhibitor which targets key enzymes in this pathway.

Binimetinib is being studied in clinical trials in advanced cancer patients, including the Phase 3 COLUMBUS trial in patients with BRAF-mutant melanoma and the Phase 3 BEACON CRC trial in patients with BRAF V600E-mutant colorectal cancer.