Merck & Co. and Incyte Corporation, a Wilmington, Delaware-headquartered biopharmaceutical company, have expanded their collaborative clinical development program for investigating the combination of epacadostat, Incyte’s investigational oral selective indoleamine-pyrrole 2,3-dioxygenase 1 (IDO1) enzyme inhibitor, with Keytruda (pembrolizumab), Merck’s anti-programmed death-1 (PD-1) therapy, in patients across five tumor types: metastatic melanoma, non-small cell lung cancer (NSCLC), bladder cancer, renal cell carcinoma (RCC), and squamous cell carcinoma of the head and neck (SCCHN).

The companies initially decided to advance their clinical development program in January 2017 to investigate this combination of their respective drugs. The new expansion to the collaboration now includes seven pivotal studies, including a Phase III study in metastatic melanoma (trial underway); two Phase III studies in first-line NSCLC, including both PD-L1 high-expressing and PD-L1 unselected populations; two Phase III studies in bladder cancer, including one in first-line bladder cancer and one in second-line bladder cancer; a Phase III study in first-line RCC; and a Phase III study in first-line SCCHN. Incyte and Merck will share responsibilities for funding these pivotal studies, and Merck will be responsible for conducting the trials.

IDO1 is an immunosuppressive enzyme that modulates the anti-tumor immune response by promoting regulatory T-cell generation and blocking effector T-cell activation. Epacadostat is a highly potent and selective oral inhibitor of the IDO1 enzyme that reverses tumor-associated immune suppression and restores anti-tumor immune responses, according to Incyte.

Merck’s Keytruda is a humanized monoclonal antibody that increases the ability of the body’s immune system to help detect and fight tumor cells by blocking the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes, according to Merck. In the US, Keytruda is approved for treating unresectable or metastatic melanoma, metastatic non-small cell lung cancer, recurrent or metastatic head and neck squamous cell carcinoma, and refractory classical Hodgkin lymphoma.

Source: Merck & Co.