Reyad Dada1,2, Binyam Usman1
1King Faisal Specialist Hospital and Research Center, Jeddah, Kingdom of Saudi Arabia,2College of Medicine, Al-Faisal University, Riyadh, Kingdom of Saudi Arabia
Background: Checkpoint inhibitors are revolutionizing the management of relapsed/refractory Hodgkin lymphoma. Despite approvals of nivolumab and pembrolizumab after autologous stem cell transplantation, a.e. to bridge patients to allogeneic stem cell transplantation, there are some concerns around an increased toxicity of allogeneic stem cell transplantation after pretreatment with checkpoint inhibitors.
Methods: We reviewed the published data of patients undergoing allogeneic stem cell transplantation after treatment with checkpoint inhibitors. Data in PubMed, EMBASE, Google Scholar and the Cochrane Library using the key words “Nivolumab”, “Pembrolizumab”, “Hodgkin lymphoma” and “allogeneic transplantation” was collected. Abstracts of recent conferences (2015–2017) of American Society for Clinical Oncology (ASCO), American Society of Hematology (ASH) and European Group for Blood and Marrow Transplantation (EBMT) were also included in the analysis. The results were compared with safety of recent studies with allogeneic stem cell transplantation in cHL (2015–2018). Two reviewers studied the publications independently and matched extracted data.
Results: Total of 259 records with 1100 patients were screened. In the investigational cohort (cohort 1) we processed data of 6 publications with a total of 122 patients. In the comparator arm (cohort 2), we found another 6 publications with 978 patients reporting on GVHD and/or NRM.
Acute grade 3–4 GVHD in cohort 1 was found in 28% in comparison with 8% in cohort 2. Chronic GVHD was observed in 26% versus 29% respectively. NRM was 15% which remained relatively stable after 6 months of allogeneic stem cell transplantation versus 19% in cohort 2. There was no association found between number of cycles of checkpoint inhibitor prior to allogeneic stem cell transplantation or days from last administration of checkpoint inhibitor to allogeneic stem cell transplantation and grade 3–4 acute GVHD.
Conclusion: This is the largest pooled analysis of its kind published so far. Based on our results, allogeneic stem cell transplantation after checkpoint inhibitors seems to be feasible and not associated with higher mortality. However, careful consideration should be given for prevention, early detection and effective treatment of GVHD in these cases.