April 9 (UPI) -- Incyte has scrapped plans for a drug to boost the effectiveness of Merck's Keytruda to treat skin cancer patients after a Phase 3 clinical trial failed.
The late-stage trial testing of Incyte's epacadostat in combination with Merck's Keytruda didn't hit its primary targets in patients with unresectable or metastatic melanoma in the Echo-301 trial, the companies announced Friday.
The companies hoped the combination of the IDO1 inhibitor and the anti-PD-1 therapy would help improve clinical outcomes for patients but it failed to improve progression-free survival in the overall population compared with Keytruda monotherapy and a placebo.
The study's second primary endpoint of overall survival is also not expected to reach statistical significance.
Keytruda, which is the brand name for pembrolizumab, has been approved by the Food & Drug Administration as an injection for treatment of melanoma, lung cancer, head and neck cancer, classical Hodgkin lymphoma, urothelial carcinoma and microsatellite instability-high cancer. It was first approved in 2014 for advanced melanoma patients.
Incyte's experimental drug epacadostat is administered orally
Researchers enrolled 706 participants in the trial starting in June 2016.
"While we are disappointed that this study did not confirm the efficacy of epacadostat in combination with Keytruda in patients with unresectable or metastatic melanoma, data from ECHO-301/KEYNOTE-252, including analyses of an extensive biomarker panel, will contribute to our understanding of the role of IDO1 inhibition in combination with PD-1 antagonists, and may inform our broader epacadostat clinical development program," said Steven Stein, chief medical officer of Incyte.
"We remain dedicated to transforming the treatment of cancer and will continue to explore how IDO1 inhibition and other novel mechanisms can potentially improve outcomes for patients in need."
Merck's Keytruda and Bristol-Myers Squibb's Opdivo dominate cancer immunotherapy. But these drugs, which allow T cells to seek out and kill cancer cells, only work for minority of cancer patients.