Role of ROCK2 inhibitors in the treatment of chronic graft-versus-host disease

INTRODUCTION: Chronic graft-versus-host disease (cGVHD) is the most common cause of late non-relapse mortality after allogeneic hematopoietic cell transplantation (allo-HCT). Rho-associated coiled-coiled kinases (ROCK) inhibitors have been shown to balance the pro-inflammatory and regulatory T-cell subsets in addition to reducing fibrosis in cGVHD, resulting in the development of multiple ROCK2 inhibitors including belumosudil. AREAS COVERED: We describe the pathophysiology of cGVHD and the role of ROCK2 in cGVHD. This includes a review of the current and ongoing clinical data with belumosudil, and an overview of current ROCK2 inhibitors in development for cGVHD, including rovadicitinib, zelasudil, and GV-101. EXPERT OPINION: Many of the recent novel agents with unique mechanisms such as ROCK2 inhibitors (i.e. belumosudil) provide high response rates but rarely yield complete responses in cGVHD. The future of management of cGVHD will rely on investigating combination therapy upfront that may achieve deeper complete responses, developing newer preventative therapies, and advancements in biomarker detection/risk stratification for cGVHD.