Single center experience with total body irradiation and melphalan (TBI-MEL) myeloablative conditioning regimen for allogeneic stem cell transplantation (SCT) in patients with refractory hematologic malignancies
Bhatnagar, B., Rapoport, A.P., Fang, H. et al. Ann Hematol (2014) 93: 653. doi:10.1007/s00277-013-1908-9
We retrospectively evaluated the tolerability and efficacy of fractionated total body irradiation (TBI) (1,200 cGy) and melphalan (MEL) (100–110 mg/m2) myeloablative conditioning in 48 patients with nonremission AML (n = 14), ALL (n = 10), NHL (n = 18), and other refractory hematologic malignancies (n = 6) who received allogeneic stem cell transplantation (SCT) between 2002 and 2011. Median age was 48 years (22 to 68); 14 out of 26 leukemia patients (54 %) had circulating blasts at transplant, 20 (50 %) evaluable patients had poor-risk cytogenetics, 12 (25 %) had prior SCT, and 10 (21 %) received stem cells from a mismatch donor. All patients received tacrolimus with or without methotrexate for GVHD prophylaxis. At the time of analysis, 13 patients (27 %) were alive and disease free. Engraftment was complete in all patients. The median time to ANC recovery (>500) was 12 days (range, 6–28). The most common grade III and IV toxicities were mucositis and infections. Eighteen patients (43 %) developed grade II–IV acute GVHD, and eight (26 %) had extensive chronic GVHD. Of 44 evaluable patients for response, 28 (64 %) achieved a complete remission (CR), and seven (15 %) had a partial remission after the transplant. With a median follow-up of 30 months (4 to 124 months) for surviving patients, the cumulative incidence of relapse was 45 % at 1 year, and the probability of overall survival (OS) at 5 years was 22.5 %. Multivariate analysis showed that platelet count (<80,000/mL) and lactic dehydrogenase (>500 IU/L) at SCT were associated with relapse. Age less than 53 years and CR after SCT were associated with better OS. Our data suggest that TBI-MEL can result in CR in two thirds, durable remission in one third, and 5-year survival in about one quarter of patients with nonremission hematologic malignancies. Further studies with TBI-MEL in standard risk transplant patients are warranted.