Phase 3 GRAVITAS-301 Study Fails to Improve Overall Responses in GVHD

The pivotal phase 3 GRAVITAS-301 study — designed to evaluate itacitinib in combination with corticosteroids in patients with treatment-naïve acute graft-versus-host disease (GVHD) – failed to meet its primary endpoint of improving overall response rates, compared with placebo.

Overall response rates with itacitinib was 74%, compared with 66.4% with placebo; however, this difference was not statistically significant. Moreover, there was no difference observed in non-relapse mortality at month six between arms.

“The result of this study is disappointing. However, we remain committed to building on the success of the REACH program for [Jakafi (ruxolitinib)], which showed positive results in steroid refractory acute GVHD. Additionally, we will continue to study the role of JAK inhibition in chronic GVHD and in the prophylactic setting, as we seek to develop treatments for patients with this debilitating and often fatal disease,” Dr. Steven Stein, chief medical officer at Incyte, said in a press release.

Incyte Corporation noted that data from the study will be submitted for presentation at an upcoming scientific meeting. “Incyte will inform investigators of the results and work with them to appropriately conclude the study in a manner consistent with the best interest of each patient,” according to the release.

In the randomized, double-blind, placebo-controlled pivotal phase three study, the researchers evaluated itacitinib or placebo, in combination with corticosteroids, as a first-line treatment for patients with acute GVHD.

The primary endpoint was defined as the proportion of patients who demonstrated a complete response, a very good partial response, or a partial response to treatment with itacitinib. The secondary endpoint was defined as the proportion of patients who died due to causes other than malignancy relapse. Other secondary endpoints include duration of response.