Vedolizumab for Steroid Refractory Lower Gastrointestinal Tract Graft-Versus-Host Disease.

Steroid-refractory (SR) lower gastrointestinal (LGI) acute graft-versus-host disease (aGVHD) has poor prognosis, and novel drugs are needed. We describe outcomes of patients with SR-LGI aGVHD treated with vedolizumab. The primary objective was to determine overall response rate (ORR) at days 14, 28, and 56. Secondary outcomes included overall survival (OS), non-relapse mortality and toxicities. Twenty patients, median age 46 years (range, 23-71), were included. All but 2 patients (90%) had grade 3 to 4 aGVHD (45% stage 4, 40% stage 3 LGI). Median time to vedolizumab was 21 days (range, 5-1031) and 13 days (range, 0-533) after diagnosis of LGI aGVHD and SR-LGI aGVHD, respectively. It was given as ≥3rd line (median 3; range 2-6) in 75% after failure of steroids, and additional treatments including ruxolitinib (n = 12) and others. Median follow-up was 17 months (range, 10-34). The days 14, 28 and 56 ORRs were 45% (9/20; complete response [CR] 25%), 35% (7/20; CR 20%), and 25% (5/20; CR 20%), respectively. Among ruxolitinib failures, it was 50% (6/12; CR 25%), 50% (6/12; CR 25%) and 25% (3/12; CR 16.7%), respectively. Fifteen patients died (14 GVHD, 1 leukemia relapse). The actuarial 6-month OS was 35% (95% confidence interval 16-55). No progressive multifocal leukoencephalopathy or infusion reaction occurred. Forty-four infection events (22 viral, 18 bacterial, and 4 fungal) were noted in 16 patients. Vedolizumab was well tolerated and demonstrated potential efficacy even after ruxolitinib failure for SR-LGI aGVHD. Yet the responses were suboptimal, and its use requires further investigation.