Belumosudil in pediatric patients with chronic graft-versus-host disease after failed multi-line therapy: a case series.

Belumosudil is a selective small molecule inhibitor of Rho-associated coiled-coil kinase 2 (ROCK2) indicated for patients with glucocorticoid-refractory chronic graft-versus-host disease (cGVHD). Despite its approval for ages 12-18, there is limited pediatric data available. This case series presents three 12-year-old patients with severe cGVHD who had failed multiple lines of therapy. Case #1 received treatment for 210 days with belumosudil, prednisone, cyclosporine A, mycophenolate mofetil, and ruxolitinib. Initial assessments showed skin and joint fascia involvement (National Institutes of Health score 3), along with oral cavity, ocular, and pulmonary involvement (score 2). Following treatment, all affected organs demonstrated at least a partial response (PR), with an overall assessment of PR. Case #2 was treated for 205 days with belumosudil, tacrolimus, and ruxolitinib. Baseline assessments indicated involvement of the skin and joint fascia (score 3), and the oral cavity and eyes (score 2). Most organs achieved PR or complete response (CR), resulting in an overall PR. Case #3 underwent 121 days of therapy with belumosudil, prednisone, and tacrolimus, showing similar baseline organ involvement as Case #2. The treatment resulted in an overall PR, with improvement noted in the skin, oral cavity, eyes, and joint fascia. The Lee cGVHD symptom scale scores improved meaningfully for all patients over time. There was no recurrence of the primary disease or any fatalities. Adverse events were limited to grade 1-2 severity. This case series indicates that belumosudil may be effective in 12-year-old pediatric patients with severe, multi-organ cGVHD refractory to multiple treatments. The findings suggest that belumosudil-based regimens can be feasible and well-tolerated in this population, providing preliminary evidence for its potential therapeutic effects in clinical management.