On May 21, positive topline results of the pivotal trial evaluating belumosudil in patients with chronic graft-versus-disease (cGvHD) were announced.1 Belumosudil (KD025) is a selective inhibitor of Rho-associated coiled-coil kinase 2 (ROCK2), involved in modulating inflammatory response. The ongoing open-label, phase II ROCKstar study (KD025-213, NCT03640481) is being conducted in adults and adolescents with cGvHD who received ≥ 2 prior lines of systemic therapy.
Previously at the interim analysis, the study had met the primary endpoint of overall response rates (ORR). Now, the topline results confirmed the finding reporting ORR of 73% (95% CI, 60–83%; p < 0. 0001) and 74% (95% CI, 62 –84%; p < 0.001) with 200 mg once and twice-daily doses of belumosudil, respectively. The complete responses were observed across all affected organ systems. At the time of the primary analysis, after a median treatment duration of 29 weeks, the median duration of response has not been reached. Almost half of the patients (49%) maintained their response for ≥ 20 weeks. However, the data is still maturing. The toxicity of belumosudil has been manageable, with no reports of cytomegalovirus infections/reactivations or serious treatment-related cytopenias.
New Drug Application submission to the U.S. Food and Drug Administration (FDA) for belumosudil (KD025) is planned for the last quarter of this year. Previously, the drug has been granted FDA Breakthrough Therapy Designation for the treatment of patients with cGVHD and an Orphan Drug Designation.
Belumosudil is also being investigated in a phase II clinical trial in adults with diffuse cutaneous systemic sclerosis (KD025-209).