Incyte Corporation announced that the first patient has been treated in GRAVITAS-309, a pivotal Phase 3 trial for the first-line treatment of patients with chronic graft-versus-host disease (GVHD). The trial will evaluate the efficacy and safety of itacitinib, Incyte’s novel and selective JAK1 inhibitor, in combination with corticosteroids compared to corticosteroids alone as a first-line treatment for moderate or severe chronic GVHD. GVHD is a condition that can occur after an allogeneic stem cell transplant (the transfer of stem cells from a donor), where the donated cells initiate an immune response and attack the transplant recipients organs, leading to significant morbidity and mortality. There are two forms of GVHD, acute and chronic, which can affect multiple organ systems including the skin, gastrointestinal (digestive) tract and liver. It is estimated that there are approximately 15,000 new cases of GVHD diagnosed each year in the U.S., Europe and Japan, where approximately 12,000 new cases are acute GVHD and 3,000 de novo cases are chronic GVHD. The prevalence of chronic GVHD in the U.S., Europe and Japan is estimated to be approximately 25,000 patients. A Phase 3 study (GRAVITAS-301) of itacitinib for the treatment of patients with acute GVHD is already underway, with results expected in 2019. GRAVITAS-309: GRAVITAS-309 (NCT03584516) is a randomized, double-blind, placebo-controlled pivotal Phase 3 study evaluating itacitinib or placebo in combination with corticosteroids as a first-line treatment for patients with chronic graft-versus-host disease (cGVHD). The study will enroll approximately 266 patients 18 years or older who have undergone one allogeneic stem cell transplant from any donor and any donor source for a hematologic malignancy or disorder. The primary endpoint of the GRAVITAS-309 study is overall response rate (ORR) at Month 6, defined as the proportion of subjects demonstrating a complete response (CR) or partial response (PR) per National Institutes of Health consensus guideline. Key secondary endpoints include the maximum (Cmax) and minimum (Cmin) observed serum concentration of itacitinib when administered in combination with corticosteroids at Day 28.