Merck KGaA's $4.2B bintrafusp alfa nabs a 3rd strike. Is the GSK-partnered cancer hopeful out?

Merck KGaA’s biliary cancer hopeful bintrafusp alfa—the immunotherapy at the heart of a $4.2 billion deal with GlaxoSmithKline—has nabbed its third strike. 

The German pharmaceutical company announced Monday that a phase 2 clinical trial of bintrafusp alfa has been discontinued, as an independent data monitoring committee has determined the study is unlikely to meet its goal of improving overall survival.

The INTR@PID BTC 055 trial was examining the drug as a first-line treatment for patients with locally advanced or metastatic biliary tract cancer in combination with the chemotherapy drugs cisplatin and gemcitabine.

This is the third strike for the therapy, leaving the future of the clinical program—as well as that megadeal—uncertain. Merck discovered the therapy in-house but was developing it with GSK through the massive multibillion-dollar deal as the next-generation Bavencio.

Strike two came in March when an independent review of the INTR@PID BTC 047 study determined that bintrafusp alfa caused an objective response rate of just 10.1%, an efficacy that was too low to support a regulatory filing. But Merck was not ready to abandon the asset, pointing to the BTC 055 study.

RELATED: GSK, German Merck's $4.2B bintrafusp alfa drug flops again, but companies squint to see glimmers of hope

Two months earlier was the first strike. Bintrafusp alfa failed in a head-to-head matchup with Merck’s rival U.S. pharma, also called Merck, and the blockbuster cancer therapy Keytruda. German Merck's therapy was always going to have a tough time matching the winner-take-all checkpoint inhibitor Keytruda, so this initial failure wasn't a major red flag. 

Now, we have a total of three red flags. 

Merck’s statement on the BTC 055 study was brief, but previous updates have detailed an expansive clinical program for bintrafusp alfa, including trials for breast cancer, urothelial cancer and cervical cancer.

The FDA’s clinical trials database lists over 40 studies involving bintrafusp alfa, which is not currently approved for any indication.