When is the best time and grade to start ruxolitinib in corticosteroid‐refractory acute graft‐versus‐host‐disease: A multi‐center research

Abstract Objective Ruxolitinib was recently approved to treat corticosteroid‐resistant acute graft‐versus‐host disease (GvHD). However, it is unknown as to whether starting ruxolitinib at a lower versus higher acute GvHD grade or earlier versus later affected outcomes. This study identified the impact of starting acute GvHD grade and start time after declaring corticosteroid resistance and the effect on complete and overall response rates to ruxolitinib therapy. Methods Retrospective, observational multi‐center study. We divided cohorts into starting ruxolitinib ≤ 7 days ( N = 45) versus at > 7 days after declaring corticosteroid resistance ( N = 24). Results In ≤ 7 days cohort complete response (CR) rates at day 28 were 69% (54, 81%) versus 25% (11, 47%; p = .001 ) in > 7 days cohort, and overall response (OR) rates were 91% (78, 96%) versus 80% (48, 92%; p = .25). Conclusions Our data suggest that starting ruxolitinib in ≤ 7 days of declaring corticosteroid failure regardless of G vHD grade improves complete response rate but not OR rates. Starting ruxolitinib at grade I and within 7 days may get a more significant response.