Non T-Depleted Bone Marrow Transplantation From Haploidentical Related Donor in Hematological Malignancies.

Abstract Abstract 2291 Poster Board II-268 Haploidentical bone marrow transplantation (BMT) is an alternative treatment to patients with high-risk hematologic malignancy lacking a HLA-matched donor and those urgently need transplantation. We used a haploidentical-BMT protocol without ex vivo T cell depleted based on the knowledge that marrow grafts have 10 times fewer lymphocytes compared to peripheral blood stem cell grafts and granulocyte colony-stimulating factor (G-CSF) donor priming reduce the incidence of acute GvHD. Materials and Methods: 40 patients (median age of 32, 12-63) with advanced disease or leukemia with poor prognostic features underwent unmanipulated haplo-BMT: 22 with AML, 9 with ALL, 3 with CML, 3 with Hodgkin lymphoma and 3 with plasmacell leukemia. Status at disease: 22 early (first or second comple! te remission), 18 advanced (progressive or refractory disease). All pairs of donors and recipients were identical for one HLA haplotype and incompatible at 2 or 3 loci.The myeloablative conditioning regimens used were different; antithymocyte globuline, cyclosporine, metotrexate, mycophenolate mofetil and basiliximab were used for GvHD prophylaxis. Donors were primed with filgrastim at 4 micrograms/Kg/d for 7 consecutive days. Bone marrow cells were harvest on the 8 day and were infused unmanipulated. Results: the median dose of total nucleated, CD34+ and CD3+cells was 7×10e8/Kg (1.01-28.7), 2.3×10e6/Kg (1.17-6.0) and 23.3×10e6/Kg (9.7-66.6) respectively. 1 patients had a primary graft failure and 5 patients died early prior to engraftment. In the remaining 34 patients, engraftment was seen with median time to granulocyte and platelet recovery of 22 and 27 days respectively; acute GvHD was grade 0 in 17 patients (50%), grade I in 9 (26%), grade II in 7 (20%) and grade IV in 1 (3%). In 29 evaluable patients, chronic GvHD was limited in 3 (10%) and extensive in 1 (3%). Transplant-related mortality at 6 months for early and advantage stage was 22% and 35% respectively. After a median follow up of 18 (3-42) months, 8 patients relapsed; 11 patients (50%) in the early stage and 4 (22%) in advanced phase are now living in haematological remission. The 1-year Kaplan-Meyer probability of disease-free survival is 45% for all patients. Conclusion: the high engraftment rate, low incidence of grade II-IV acute GvHD and an acceptable TRM suggest that G-CSF-primed marrow grafting along with sequential immunosuppression could provide an excellent alternative for patients who lack matched donors. Disclosures: No relevant conflicts of interest to declare.