Safety and Efficacy of Vedolizumab for the Patients With Gastrointestinal Acute Graft‐Versus‐Host Disease Refractory to Steroid Treatment After Allogeneic Hematopoietic Stem Cell Transplantation: A Real‐World, Retrospective Multicenter Study (VAST Study)

Steroid-refractory (SR) gastrointestinal (GI) acute graft-versus-host disease (aGVHD) is the major cause of early mortality after allogeneic hematopoietic stem cell transplantation. Vedolizumab could be used as the second- or third-line treatment of GI-aGVHD. Our real-world, retrospective multicenter study, in which 100 SR-GI-aGVHD patients who received vedolizumab were enrolled, confirmed its effectiveness. Note that 411 SR-GI-aGVHD patients who received the best available treatments (BATs) during the same period were enrolled as controls. Inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) were conducted as sensitivity analyses. The overall response rates (ORRs) for SR-GI-aGVHD on day 28 and at any time point were 68.0% and 81.0%, respectively, and the 2-year probabilities of overall survival and nonrelapse mortality were 58.3% and 31.9%, respectively, after vedolizumab treatment. Multivariate analysis revealed that initiating vedolizumab treatment within 7 days after SR-aGVHD onset could help improve the ORR. In the sensitivity analysis, compared with the BATs, vedolizumab improved the ORR and complete response rate, particularly in the stage 3-4 SR-GI-aGVHD subgroup, and it reduced the infection rate after IPTW and PSM adjustment. These findings confirmed the efficacy of vedolizumab in a real-world setting, which can help to control SR-GI-aGVHD more effectively and safely.