Allogeneic hematopoietic cell transplant (allo-HCT) remains a treatment option for relapsed/refractory (R/R) lymphoma patients who are ineligible for or relapse after autologous HCT. A retrospective study by Narendranath Epperla et al assessed the outcomes of lymphoma patients from a multi-institutional database who had relapsed after allo-HCT in order to determine whether the use of salvage therapies can improve survival outcomes. This study was accepted to be published in Biology of Blood and Marrow Transplantation in January 2018.
One hundred and twenty-six patients from three US medical centers who had received allo-HCT between 2000-2015 were alive one month after allo-HCT and were included in the study analysis. Patients had a diagnosis of either aggressive non-Hodgkin lymphoma (NHL) (52%), Hodgkin lymphoma (HL) (36%) or indolent NHL (12%). The primary endpoint was post-relapse overall survival (PR-OS) with a secondary endpoint to identify risk factors affecting PR-OS.
The median patient age was 45 years and the median time to relapse was 114 days post allo-HCT. 117 patients received salvage therapy with 80 patients receiving targeted therapy, 37 receiving non-targeted therapy and 9 patients had no intervention. Targeted therapy interventions included a wide range of treatments including; monoclonal antibodies, antibody drug conjugates, immunomodulators, proteasome inhibitors, histone deacetylase inhibitors and B-cell receptor pathway inhibitors. Non-targeted therapies included immunosuppression taper alone, cytotoxic chemotherapy and radiation therapy.
The median PR-OS was 47.9 months for HL, 11.3 months for indolent lymphoma and 10.1 months for aggressive non-NHL. The univariate analysis showed that HL patients had significantly longer PR-OS compared with the lymphomas (P = 0.04). Patients achieving partial response (PR) or complete response (CR) after the first salvage therapy also had prolonged PR-OS compared to non-responders (46.8 vs 11.3 months, P = 0.02). Patients who received targeted therapy had longer PR-OS (38.7 months) compared with patients receiving non-targeted (22.8 months) and no treatment (1.4 months).
The multivariate analysis identified that later relapse after allo-HCT (≥130 days) had significantly better PR-OS than early relapse (48.8 vs 6.5 months, P < 0.001). Additionally, treatment with salvage therapies and Eastern Cooperative Oncology Group (ECOG) performance status 0-1 was also associated with improved post-relapse survival outcomes. The main cause of death was documented as disease progression (n = 45).
The authors observed from their study results that the use of salvage therapies could improve survival outcomes in lymphoma patients after allo-HCT and recommend that this patient population are also considered for clinical trials researching targeted therapies.