Dr. Cutler on the Efficacy Results of the ROCKstar Study in cGVHD

Corey S. Cutler, MD, MPH, FRCPC, medical director, Adult Stem Cell Transplantation Program, director of Clinical Research, Stem Cell Transplantation, director, Stem Cell Transplantation Survivorship Program, institute physician, Dana-Farber Cancer Institute, and associate professor of medicine, Harvard Medical School, discusses ​the efficacy results of the ongoing phase 2 ROCKstar trial (NCT03640481) in patients with chronic graft-versus-host disease (cGVHD).

The ROCKstar study randomized patients with cGVHD who received at least 2 prior lines of systemic therapy to receive 200 mg of belumosudil (KD025), a ROCK2 inhibitor, once or twice daily. Findings from the study, which were presented virtually during the 47th Annual Meeting of the EBMT, demonstrated an overall response rate of 73% in the once daily arm and 77% in the twice weekly arm per the 2014 National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in cGVHD.

Additionally, complete responses (CRs) were observed in all affected organ systems, including the joints/fascia, lower and upper gastrointestinal tracts, mouth, esophagus, eyes, skin, liver, and lungs. Some organ systems responded more quickly or more completely compared with others, Cutler explains. For example, the 54% response rate observed in the mouth was comprised of CR and partial response (PR) rates of 43% and 11%, respectively. Conversely, the 67% response rate reported in the joints/fascia was comprised of CR and PR rates of 20% and 47%, respectively. Reversing fibrosis in the joints/fascia takes a long time and is often incomplete, which accounts for the low CR rate in this organ system, concludes Cutler.