Patient‐Reported Symptom Burden and Objective Responses After Belumosudil in Heavily Pretreated Chronic GvHD

BACKGROUND: Belumosudil has demonstrated clinical activity in chronic graft-versus-host disease (cGvHD), but its impact on patient-reported symptom burden in routine practice remains incompletely characterized. OBJECTIVE: To evaluate longitudinal changes in cGvHD-related symptom burden during belumosudil-containing therapy, using the modified Lee symptom score (mLSS). METHODS: This retrospective, multicenter study included 87 heavily pretreated patients with cGvHD from four Canadian centers. We scored the mLSS at baseline and 3, 6, and 12 months after belumosudil initiation. Clinically meaningful improvement (CMI) was a ≥ 6-point reduction in the overall mLSS. We analyzed longitudinal changes using a linear mixed-effects model. RESULTS: Item-level data were available for 48 patients (55%). Mean ± standard error mLSS decreased from 25.4 ± 1.8 at baseline to 16.5 ± 2.3 (n = 25), 14.6 ± 3.0 (n = 14), and 15.6 ± 4.5 (n = 8) at 3, 6, and 12 months (p < 0.001). CMI occurred in 52%, 64%, and 50% of evaluable patients, but in 15%, 10%, and 5% of all 87 treated patients. Best CMI was 65% (n = 17/26) of evaluable patients and 20% of all treated patients, and best overall response rate was 41% (n = 32/78). CONCLUSIONS: Belumosudil-containing therapy was associated with reduced symptom burden among patients with evaluable item-level data. Declining data capture limits conclusions about durability and generalizability; prospective studies with systematic symptom burden capture are needed.