Reduced-Intensity Allogeneic Transplantation Provides High Event-Free and Overall Survival in Patients with Advanced Indolent B Cell Malignancies: CALGB 109901

CALGB conducted a Phase II study to evaluate the safety and efficacy of a reduced-intensity conditioning regimen with allogeneic transplantation to treat patients with recurrent low grade B cell malignancies. Patients over age 18 with a diagnosis of relapsed, chemotherapy-sensitive disease underwent transplantation with a matched sibling donor and conditioning with cyclophosphamide (1 g/m2/d × 3) and fludarabine phosphate (25 mg/m2/d × 5). GVH prophylaxis included cyclosporine or tacrolimus plus low-dose methotrexate. Forty-four evaluable patients with a median age of 53 and median of two prior regimens were accrued. Sixteen patients had follicular NHL and 28 had histologies including 7 indolent B cell lymphomas, 4 mantle cell, 15 chronic lymphocytic leukemia, and 2 prolymphocytic leukemia pts. The six-month treatment-related mortality (TRM) was 2.4% and three-year TRM was 9%. Three-year event-free and overall survival were.75 and .81 for the follicular patients, .59 and .71 for the CLL/PLL patients, and .55 and .64 for the other histologies. The incidence of grade 2–4 acute graft vs host disease (GVHD) was 29% and extensive chronic GVHD was 18%. This report demonstrates that allogeneic sibling transplantation with a reduced intensity conditioning regimen is safe and efficacious for patients with advanced indolent B cell malignancies enrolled on a Cooperative Group study