Merck's blockbuster drug Keytruda and Eisai's cancer drug Lenvima, in combination with chemotherapy, failed to improve overall survival in patients with a type of esophageal cancer in a late-stage trial,

Merck & Co. and Eisai have to deal with the reality that yet another phase 3 trial of their combination of Keytruda and Lenvima didn’t exactly go their way. | Merck & Co. and Eisai have to deal with the reality that yet another phase 3 trial of their combination of Keytruda and Lenvima didn’t exactly go their way.

The unsuccessful Phase III results are the latest to suggest that the blockbuster cancer drug is finally bumping up against its limits after racking up around 50 approvals since getting its first FDA nod in September 2014.

Merck and Japan-based Eisai said on Friday a combination of their therapies failed to extend the lives of patients with a type of esophageal cancer in a late-stage trial. The trial was studying U.S. drugmaker Merck's blockbuster immunotherapy Keytruda and Eisai's Lenvima,

Merck and Co. expects to launch an easier-to-administer version of its blockbuster cancer treatment Keytruda before the end of the year.

Co., Inc. (NYSE:MRK) and Eisai Co., Ltd. (TYO:4523) have announced the latest outcomes from their Phase 3 LEAP-015 trial, which evaluated the efficacy of the combination therapy KEYTRUDA and LENVIMA for patients with advanced gastroesophageal adenocarcinoma.