Impact of Rituximab and Host/Donor Fc Receptor Polymorphisms after Allogeneic Hematopoietic Cell Transplantation for CD20+ B-cell Malignancies. Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Granot, N., Rezvani, A. R., Pender, B. S., Storer, B. E., Sandmaier, B. M., Storb, R., Maloney, D. G. 2020

Abstract

We previously reported a 24% 1-year relapse rate in 93 older or medically unfit patients with CD20+ B-cell malignancies after low-intensity conditioning and allogeneic hematopoietic cell transplantation. The current prospective study tested the hypothesis that disease relapse could be reduced, and overall survival improved, by peri-transplant rituximab. Sixty-three patients received rituximab (375 mg/m2/day) on days -3, +10, +24 and +38 in addition to 2-3 Gy total body irradiation ± fludarabine (30 mg/m2?*?3 days). Median rituximab levels of >25 mug/mL were achieved through day +84 after transplant, but levels were not correlated with relapse or graft-vs.-host disease incidence. Recipients with F/F and V/F FCgammaRIIIa polymorphisms showed a trend toward higher relapse rates compared to recipients with V/V polymorphism (p=0.15). No difference in outcome was found with V/V donor pairing. Five-year relapse rates were similar among rituximab-treated patients and historical controls (32% vs, 28%; P=0.94). Rituximab-treated patients experienced higher 5-year overall survival and progression-free survival (47% vs. 38%; P=0.13, 41% vs. 32%; P=0.12, respectively) compared to historical controls transplanted without rituximab, although not statistically significant. Incidences of acute graft-vs.-host disease were similar (Grade II-IV, 57% vs. 56%; Grade III-IV, 13% vs. 17%); and 5-year chronic graft-vs.-host disease incidence was higher among rituximab-treated patients (62% vs. 47%). In patients with relapsed or refractory non-Hodgkin lymphoma, peri-transplant rituximab neither reduced relapse nor improved graft-vs.-host disease. The role of donor-recipient pairing by FCgammaRIIIa polymorphisms in outcome remains to be determined.

View details for DOI 10.1016/j.bbmt.2020.07.014

View details for PubMedID 32693210