Belumosudil Versus Ruxolitinib for Steroid-Refractory or Breakthrough Hepatic cGVHD

This prospective, randomized, open-label, multicenter trial aims to compare second-line treatment strategies for hepatic cGVHD after allo-HSCT. Ruxolitinib and belumosudil are both effective for cGVHD, but no head-to-head comparison specifically in hepatic cGVHD has been reported. Two cohorts are enrolled: Cohort 1 comprises patients with steroid-refractory hepatic cGVHD without prior ruxolitinib or belumosudil exposure, randomized to receive either agent. Cohort 2 includes patients who develop new-onset hepatic cGVHD after ≥4 weeks of therapy with ruxolitinib or belumosudil for other-organ cGVHD (stable for ≥2 weeks), or patients with non-response/progression on either agent for hepatic cGVHD; these patients will be switched to the opposite drug. Key questions include: • In steroid-refractory hepatic cGVHD, does 24-week hepatic overall response rate differ between belumosudil and ruxolitinib? • What is the hepatic response rate after drug switching in Cohort 2? • How do the two agents compare in safety and tolerability for hepatic cGVHD? • What are their impacts on corticosteroid tapering, failure-free survival, and long-term outcomes? Participants will: • Receive assigned treatment per cohort and randomization • Undergo regular efficacy/safety monitoring, including hepatic cGVHD scoring, liver function tests, and adverse event recording • Provide peripheral blood samples at baseline and multiple on-treatment time points for exploratory biomarker analysis • Complete 24-week primary efficacy assessment with follow-up until progression or discontinuation Primary endpoint is 24-week hepatic overall response rate (CR+PR, per 2014 NIH cGVHD criteria). Secondary endpoints include duration of response, failure-free survival, corticosteroid tapering rate, safety (AE/SAE incidence), liver function improvement, and patient-reported outcomes. This head-to-head comparison will provide high-level evidence for selecting second-line and beyond therapies for hepatic cGVHD.