Already playing catch-up in the immuno-oncology market, Merck KGaA and Pfizer’s hopes for their PD-L1 inhibitor Bavencio just took a knock with a failed trial in stomach cancer.
Bavencio (avelumab) failed to improve overall survival compared to standard chemotherapy when given as a third-line treatment to patients with advanced gastric cancer in the JAVELIN Gastric 300 trial.
The drug is already approved as a treatment for rare cancer Merkel cell carcinoma and as a second-line therapy for bladder cancer (metastatic urothelial carcinoma), but Pfizer and Merck are hoping to add a steady stream of new indications for a product that is seen as important for both companies’ growth prospects.
Merck’s R&D head Luciano Rossetti said the failure was likely because the study pitted Bavencio against chemotherapy, rather than placebo.
“Gastric cancer in the third-line setting is a particularly hard-to-treat and heterogeneous disease, and importantly, this was the first trial conducted with a checkpoint inhibitor compared to an active chemotherapy comparator rather than placebo in a global patient population,” he noted.
That doesn’t alter the fact that gastric cancer is a big market opportunity, as the fifth most- common form of cancer, and could have added considerable momentum to Bavencio’s growth as it chases the its rivals in the {D-1/PD-L1 inhibitor category. These include Merck & Co’s Keytruda (pembrolizumab) and Bristol-Myers Squibb’s Opdivo (nivolumab), both of which have picked up regulatory approvals in third-line stomach cancer.
Rossetti said the two partners haven’t given up on stomach cancer just yet and “remain committed to our ongoing gastric cancer programme with avelumab including the JAVELIN Gastric 100 study in the first-line switch maintenance setting.”
Bavencio is one of five PD-1/PD-L1 targeting drugs on the market, and along with Roche’s Tecentriq (atezolizumab) and AstraZeneca’s Imfinzi (durvalumab) is trying to carve itself a niche in a market still dominated by Opdivo and Keytruda.
Most of the drugs have run into trouble at some point, emphasising that immuno-oncology is still in its infancy and there is a lot to learn about how to best use them in cancer treatment.
Opdivo failed a trial in first-line lung cancer, while Keytruda flunked a test in head and neck cancer. Tecentriq had a shock miss in a third-line bladder cancer trial – despite already being approved on the strength of phase II data – and a much-touted trial combining AZ’s Imfinzi with CTLA4 inhibitor tremelimumab ended in failure.
One criticism levelled at the developers of these checkpoint inhibitors is that they are running too many trials, trying to chance on the right drug indications and combinations without sufficient scientific rigour. That explosion in testing can only mean tougher challenges and more failures.