A study to investigate the efficacy and safety of belumosudil compared with best available therapy in participants aged 12 years or older with chronic graft-versus-host disease.

INTERVENTION: Product Name: , Product Code:SCP183235, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP31316403, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP159589, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP10367371, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP872361, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP101121559, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP1705870, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP1034223, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP109528812, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: , Product Code:SCP15688202, Pharmaceutical Form: , Other descriptive name: , Strength: , Product Name: REZUROCK 200 mg film‐coated tablets, Product Code:PRD13811034, Pharmaceutical Form: FILM‐COATED TABLET, Other descriptive name: , Strength: , Product Name: , Product Code:SCP139856, Pharmaceutical Form: , Other descriptive name: , Strength: CONDITION: Immune system diseases ; MedDRA version: 27.0Level: PTClassification code: 10066261Term: Chronic graft versus host disease Class: 100000004870 Therapeutic area: Diseases [C] ‐ Immune System Diseases [C20] PRIMARY OUTCOME: Main Objective: To demonstrate the superiority of belumosudil versus BAT in ORR at 24 weeks in participants with cGVHD. Primary end point(s): Overall response rate Secondary Objective: To demonstrate the superiority of belumosudil versus BAT in FFS., To assess clinically relevant symptom improvement measured by the modified Lee cGVHD Symptom Scale score at 24 weeks., To assess the ORR by 24 weeks., To assess the best ORR., To assess the DOR., To assess the TTR., To assess the TTNT., To assess the response by organ system., To assess the OS., To assess the change in CS doses., To assess the change in CNI doses., To assess the safety and tolerability of study treatment in participants with cGVHD., To assess the incidence of relapse or recurrence of the underlying disease., To evaluate PK of belumosudil., To assess the impact of study treatment on quality‐of‐life. SECONDARY OUTCOME: Secondary end point(s):Belumosudil plasma concentrations. Secondary end point(s):Change from baseline in SF‐36v2 domain scores and composite Physical Component Summary (PCS) and Mental Component Summary (MCS) scores. Secondary end point(s):Incidence of TEAEs, SAEs, and AESIs. Secondary end point(s):Proportion of participants achieving at least 6‐point reduction from baseline in the modified Lee cGVHD Symptom Scale score at Week 24. Secondary end point(s):Proportion of participants who achieve an overall response (CR or PR) based on NIH consensus response criteria (2014) at any time until start of new systemic therapy for cGVHD. Secondary end point(s):Proportion of participants who achieve an overall response (CR or PR) within up to 24 weeks and without the requirement of new systemic therapy as per NIH consensus response criteria (2014). Secondary end point(s):Proportion of participants who achieve CR or PR based on NIH consensus criteria (2014) at any time point in each involved organ and before the start of new systemic therapy for cGVHD. Secondary end point(s):Proportion of participants with >50% reduction from baseline in daily CNI dose at Week 24. Secondary end point(s):Proportion of participants with >50% reduction from baseline in daily CS dose at Week 24. Secondary end point(s):Proportion of participants with discontinuation of CNI at Week 24. Secondary end point(s):Proportion of participants with discontinuation of CS at Week 24. Secondary end point(s):The cumulative incidence of relapse or recurrence of the underlying disease at any time during the study. Secondary end point(s):The time from first response of PR or CR until documented progression, new systemic treatment for cGVHD, or death, whichever occurs first. Secondary end point(s):The time from the date of randomization to the date of death from any cause. Secondary end point(s):Time from randomization to the first response (either CR or PR) per NIH consensus response criteria (2014) for cGVHD. Secondary end point(s):Time from the date of randomization to the date of start of new systemic treatment for cGVHD, relapse or recurrence of underlying disease, or death, whichever occurs first. Secondary end point(s):Time from the date of randomization to the date of starting a new systemic therapy for cGVHD. INCLUSION CRITERIA: Participant must be at least 12 years of age at the time of signing the informed consent., Contraceptive use by men and women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies., Participants who have undergone allo‐HCT., Participants with active moderate to severe cGVHD at the time of enrollment, defined using the NIH Consensus diagnosis and staging criteria for which the physician believes a new line of systemic therapy is required., Participant receiving systemic CNI and/or CS must be on a stable dose/regimen (prednisone equivalent <1 mg/kg/day for CS) for at least 2 weeks prior to randomization., cGVHD is refractory to, or has recurred following, at least 2 prior lines of systemic treatment. Participants must have received a minimum of 2 and a maximum of 5 prior systemic therapies for cGVHD., Participant must have received ruxolitinib for the treatment of cGVHD unless the Investigator be