An investigator-led trial combining Incyte's IDO1 inhibitor epacadostat (INCB024360) with the MELITAC 12.1 multipeptide vaccine did not successfully boost tumor-fighting T cells in melanoma patients. Incyte supplied epacadostat, an oral small-molecule inhibitor, for the study.
The vaccine was intended to increase the number of T cells able to recognize melanoma, while epacadostat was meant to stop tumors from suppressing that immune response. The combination failed to meet its primary objective of overcoming the tumor's defenses and enabling vaccine-stimulated T cells to work effectively.