Safety and efficacy of allogeneic stem cell transplantation after nivolumab therapy for patients with relapsed/refractory classical Hodgkin lymphoma

Abstract

Abstract Background The programmed-death 1 (PD-1) blockade with nivolumab has demonstrated high efficiency in patients with relapsed and refractory Hodgkin lymphoma (rrHL) with an acceptable toxicity profile. However, most patients treated with immune checkpoint inhibitors (CPIs) will eventually progress on these therapies. Allogeneic hematopoietic stem cells transplantation (allo-HSCT) is a potentially curative option for patients with rrHL. There are concerns that CPIs before allo- HSCT may increase the incidence of graft-versus-host disease, immune-related adverse events, and nonrelapse mortality (NRM). At present, there is no consensus regarding the optimal transplant strategy for patients previously treated with immune checkpoint blockade. The aim of this study was to evaluate outcomes in patients with rrHL who received CPIs as a bridge to allo-HSCT. Methods We evaluated the results of allo-HSCT in 20 patients who had been transplanted after prior PD-1 blockade between 2017 and 2019. All patients received reduced-intensity conditioning regimen and post-transplant cyclophosphamide (PTCy)-based GvHD prophylaxis. The best response to PD-1 therapy was a complete response in 9 patients, partial response in 4; 5 patients received transplant during the disease progression and 2 patients were transplanted in indetermined response. Results At the time of analysis, median follow-up was 14 months (range, 1-26 months). The 1-year OS and EFS were 95% and 85% respectively, whereas the 1-year cumulative incidences of relapse and NRM were 10% and 5% respectively. Two patients with relapse after allo-HSCT were treated with donor lymphocyte infusion (DLI) in combination with chemotherapy. At the median follow up of 30 days all patients remain alive. 4/20 patients developed severe grade 3-4 GvHD and only 1 patient responded to steroids. The cumulative incidence of chronic GVHD (cGVHD) was 35%. Conclusion Our study demonstrates that HSCT after PD-1 blockade is feasible and not associated with higher mortality. The rate of severe acute and chronic GvHD was relatively higher than previously reported for PTCy-based prophylaxis, but was manageable in the majority of cases. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.