PB1855 UPFRONT HAPLOIDENTICAL TRANSPLANT IN YOUNG SEVERE APLASTIC ANEMIA PATIENTS ‐ RESULTS OF A PILOT STUDY FROM SOUTH INDIA

Abstract

Background:Haploidentical bone marrow transplant is one of the second line treatment option in severe aplastic anemia patients failing immunosuppressive therapy. In younger patients, allogeneic bone marrow transplant from a matched sibling donor gives more than 80% long‐term remission rates. But unfortunately, only 30% patients will have a matched sibling donor. In a middle‐income country like India, the availability and affordability of patients to an unrelated donor is limited. Most of our patients have got a single chance for treatment and many relapsed patients go into palliative care.Aims:Aim of the present study is to evaluate the efficacy and safety of upfront Haploidentical bone marrow transplant in less than 40 years old severe aplastic anemia patients not having a 10/10 matched donor.Methods:This is a prospective non‐randomized single center study conducted during the period from January 2017 to June 2018. Eleven patients less than 40 years old underwent upfront Haploidentical bone marrow transplantation for severe aplastic anemia during the above period. Peripheral blood stem cell was used in all patients.FLU‐ATG‐PTcy was the conditioning regimen used in all patients with Cyclosporine + MMF based GVHD prophylaxis. This study got clearance from institutional review board and the transplant was sponsored by government.Results:In six patient's donors were parents (Mother in four and father in two) and rest of the donors were siblings. Two were Fanconi positive and none had a PNH clone. Seven were 5/10 matched, three were 6/10 and one was 7/10 matched. All patients had engraftment at a median of 11 days (range 8 to 13 days). One patient had fatal grade IV acute GVHD and succumbed to GVHD on day +36. Seven patients (64%) had grade I/II GVHD and three patients (27%) had grade III GVHD. 64% patients had grade I/II chronic GVHD at date cut off of January 2019. 10 patients (89%) attained complete remission and were alive till January 2019.The overall survival rate at one year post transplant was around 89% which is better than immuno‐supressive therapy in this age group. No differnces were observed in engraftment dates or survival outcomes based on type of donor and degree of mismatch. The study patients are very small to get statistically significant rates.Summary/Conclusion:With nearly 90% overall remission and survival rate at one year, upfront haploidentical transplant seems to be a safe and effective option in young patients with severe aplastic anemia. This will help to reduce the cost of Matched unrelated donor stem cells significantly in resource poor countries and increase the number of patients opting for a curative treatment.