Eisai, Merck enter clinical trial collaboration

TOKYO & KENILWORTH, N.J.—Eisai Co. Ltd. and Merck & Co., known as MSD outside the United States and Canada, through a subsidiary, have announced a clinical trial collaboration under which they will evaluate the safety, tolerability and efficacy of Merck's anti-PD-1 therapy, pembrolizumab (which is marketed in the United States as KEYTRUDA), in combination with Eisai oncology compounds lenvatinib mesylate and eribulin mesylate in multiple clinical trials. Lenvatinib mesylate is a multi-targeting receptor tyrosine kinase (RTK) inhibitor marketed in the United States as LENVIMA, and eribulin mesylate is a microtubule dynamics inhibitor marketed in nearly 60 countries as HALAVEN.

“This collaboration could be a major step in the direction of developing combination regimens in different types of cancer, potentially maximizing the value of eribulin and lenvatinib,” said Dr. Kenichi Nomoto, president of the oncology product creation unit for Eisai Product Creation Systems. “Together, Eisai and Merck seek to explore combination regimens that have the potential to create synergistic effects between lenvatinib and pembrolizumab as well as between eribulin and pembrolizumab. Our hope is that we will bring treatments to market that make a difference in the lives of people battling cancer.”

Under this collaboration, Eisai and Merck plan to conduct a multi-center, open-label Phase 1b/2 study of lenvatinib plus pembrolizumab in select solid tumors, and an open-label, single-arm, multi-center Phase 1b/2 study to evaluate the efficacy and safety of eribulin in combination with pembrolizumab in metastatic triple-negative breast cancer. Both of these studies are expected to begin in the second half of this year. The two companies will establish a joint development committee that will oversee clinical development activities. No financial terms were released.

Merck's KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between programmed death receptor-1 (PD-1) and its ligands, PD-L1 and PD-L2. The drug is indicated in the United States as a treatment for patients with unresectable or metastatic melanoma and disease progression following ipilimumab and, if BRAF V600 mutation-positive, a BRAF inhibitor. That indication is approved under accelerated approval based on tumor response rate and durability of response, but an improvement in survival or disease-related symptoms has not yet been established.

“Cancer is a complex disease that often requires different approaches to help patients achieve the best

possible outcome,” Dr. Eric Rubin, therapeutic area head of oncology early-stage development at Merck Research Laboratories, commented in a press release. “The collaboration with Eisai exemplifies Merck’s focus on advancing breakthrough science in immuno-oncology. We look forward to evaluating pembrolizumab in combination with eribulin and also with lenvatinib in different tumor types.”

This is the second such collaboration Merck has established to evaluate combinations of KEYTRUDA (pembrolizumab) with other anti-cancer compounds. In mid-January, Merck announced a clinical trial collaboration with Eli Lilly & Co. that involves several combination trials. Among those are the following: Merck will conduct a Phase 2 study to evaluate the combination of pembrolizumab with pemetrexed in first-line non-squamous, non-small cell lung cancer (NSCLC); Lilly will conduct a multiple-arm Phase 1/2 study evaluating the combination of ramucirumab with pembrolizumab in multiple tumors; and Lilly will conduct a Phase 1/2 study to examine the combination of necitumumab with pembrolizumab in NSCLC.