Incyte Corporation (Nasdaq: INCY) today announced that preliminary results from an ongoing Phase I/II study of INCB24360, its oral indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor, combined with ipilimumab in patients with unresectable or metastatic melanoma were presented at the 50 th Annual Meeting of the American Society of Clinical Oncology (ASCO), May 30 to June 3, 2014, in Chicago. The poster reported initial findings showing that the combination was generally well tolerated and produced evidence of clinical response. In the study, 42 percent (5/12) of immunotherapy-naïve patients who received ipilimumab with INCB24360 at 25 mg or 50 mg twice-daily demonstrated an objective response (complete response + partial response) and 75 percent (9/12) achieved disease control (complete response + partial response + stable disease) as assessed using immune-related response criteria (irRC). One patient with pulmonary metastases treated with ipilimumab and INCB24360 50 mg twice-daily experienced a complete response. Immune-related adverse events observed in these cohorts were generally mild-to-moderate (Grade 1 or Grade 2). Grade 3 or 4 immune related adverse events were qualitatively similar to ipilimumab monotherapy and were generally manageable and reversible. “In addition to seeing disease control among the 12 immunotherapy-naïve patients, many of these patients also experienced substantial reduction in tumor burden,” said Geoffrey T. Gibney, M.D., Moffitt Cancer Center, who presented the study findings. “These preliminary data suggest INCB24360 may improve patient outcomes with manageable toxicity when combined with ipilimumab.” “Immune-targeted combination therapy represents one of the most promising approaches in oncology and our preclinical data suggested that combination of an IDO1 inhibitor with checkpoint inhibitors could have significant anti-tumor synergy,” said Hervé Hoppenot, President and Chief Executive Officer, Incyte. “The synergistic activity observed between INCB24360 and ipilimumab increases our confidence in the value of investigating other immunotherapy combinations with INCB24360 in multiple tumor types.” The poster for this presentation can be accessed at 2014 ASCO - INCB24360 poster. About the Study The ASCO presentation described results from the open-label, dose escalation portion of the ongoing Phase I/II study evaluating the combination of a standard regimen of ipilimumab with oral INCB24360. Study endpoints included safety and tolerability, objective response rate (assessed using irRC and RECIST 1.1 criteria every nine weeks), duration of response, overall and progression-free survival, and IDO1 inhibition.