Lower incidence of chronic graft-versus-host disease after ruxolitinib plus extracorporeal photopheresis versus ruxolitinib alone in steroid-refractory acute graft-versus-host disease following allogeneic stem cell transplantation.

We compared long-term outcomes in 78 patients with steroid-refractory acute graft-versus-host disease (SR-aGvHD) treated at the University Medical Center Hamburg, Germany, between December 2015 and August 2022 who received either ruxolitinib alone (Ruxo, N=29) or Ruxo plus extracorporeal photopheresis (Ruxo-ECP, N=49). Patients were well balanced between both arms except for SR-aGvHD grade IV which was higher in the Ruxo-ECP group (45% vs. 14%, P<0.001). In both cohorts, steroids were tapered rapidly, and median steroid treatment was 39 days in Ruxo and 35 days in Ruxo-ECP. The overall response rate including complete remissions (CR) of aGvHD at day 28 was 90% and 31% for Ruxo versus 86% and 0% (P<0.001, respectively) for Ruxo-ECP. At six months, partial remission (PR) and CR status of evaluable patients was 11% and 50% in Ruxo-ECP versus 10% and 40% after Ruxo alone, respectively (P=0.018). At 12 months, PR and CR status was 6% and 17% in the Ruxo group, but 82% and 64% (P<0.001) in the Ruxo-ECP cohort, and the cumulative incidence of chronic GvHD was significantly higher after Ruxo versus Ruxo-ECP at 49% (95% CI: 33-69%) versus 24% (95% CI: 15-38%) (P=0.01). Reconstitution of B cells occurred significantly earlier at one and three months in the Ruxo arm. No difference in 1-year non-relapse mortality, relapse, and 2-year overall survival was observed. Despite the limitations of this retrospective single- center study, the data suggest a better long-term control of aGvHD and less chronic GvHD at one year combining ruxolitinib with ECP compared to ruxolitinib alone in SR-aGvHD.