Incyte Corporation announced that the pivotal Phase 3 GRAVITAS-301 study evaluating itacitinib in combination with corticosteroids in patients with treatment-naïve acute graft-versus-host disease did not meet the primary endpoint of improving overall response rate at Day 28 compared to placebo plus corticosteroids (74.0% vs. 66.4%, p=0.08, respectively). Itacitinib added to corticosteroids improved the overall response rate in patients with treatment-naïve acute GVHD; however, the difference versus placebo plus corticosteroids was not statistically significant. In addition, there was no difference observed in non-relapse mortality at Month 6, the study’s key secondary endpoint, between the treatment and placebo arms. The safety profile observed in GRAVITAS-301 was consistent with that observed in previously reported studies of itacitinib in combination with corticosteroids. The most common adverse events were thrombocytopenia (34.9 % for itacitinib and 34.7% for placebo) and anemia (29.8% for itacitinib and 25.0% for placebo).