Early results from a phase 2 trial (NCT03019640) have shown promising outcomes for patients with B-cell non-Hodgkin lymphoma (NHL) undergoing treatment with cord blood-derived natural killer (NK) immunotherapy alongside high-dose chemotherapy and autologous stem cell transplant (ASCT). The trial focused on the potential of this novel cellular therapy in inducing early antitumor responses.
Patients aged 15 to 70 with B-cell NHL, excluding primary central nervous system lymphoma, were eligible for the study provided they had adequate end-organ function, an ECOG performance status of 0 or 1, and prior apheresis of ≥2 x 10^6 CD34+ cells/Kg. The treatment regimen included intravenous carmustine, etoposide, cytarabine, melphalan, and oral lenalidomide, with CD20-positive patients also receiving rituximab.
Cord blood-derived expanded allogeneic NK cells were administered intravenously five days prior to ASCT, followed by daily subcutaneous filgrastim starting five days post-ASCT. The study's primary endpoint was 30-day treatment-related mortality, with secondary endpoints including relapse-free survival (RFS), overall survival, and NK cell persistence.
Among the 19 treated patients, the median age was 60 years, with the majority being male and having diffuse large B-cell lymphoma (DLBCL). Response assessments through PET at ASCT showed a complete response in 78.9% of patients, partial response in 15.8%, and progressive disease in 5.3%. The study found that cord blood-derived NK cells were expanded significantly and maintained high viability, with NK cells detectable in the peripheral blood for a mean of 2 weeks.
At a median follow-up of 18 months, the RFS rate was 68%, and the overall survival rate was 84%. The study concluded that expanded and highly purified cord blood-derived NK immunotherapy is safe and shows promise in combination with high-dose chemotherapy and ASCT for treating B-cell NHL.
