Post-Transplantation High Dose Cyclophosphamide As Gvhd Prophylaxis in 9/10 HLA-Matched Unrelated Donors Hematopoietic Stem Cell Transplantation

• Published in: Blood 2015-12, Vol.126 (23), p.3135-3135
• Main Authors: Mehta, Rohtesh S., Saliba, Rima M, Chen, Julianne, Rondon, Gabriela, Hammerstrom, Aimee E, Alousi, Amin M., Qazilbash, Muzaffar H., Bashir, Qaiser, Ahmed, Sairah, Popat, Uday R., Hosing, Chitra M., Khouri, Issa F., Shpall, Elizabeth J., Champlin, Richard E., Ciurea, Stefan O.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V126.23.3135.3135

Background: Post-transplantation cyclophosphamide (PTCy) is an effective strategy to prevent GVHD after haploidentical or HLA-matched related or unrelated donor hematopoietic stem cell transplantation (HSCT). Our study aim was to determine its efficacy in HLA-mismatched unrelated donor (MMUD) HSCT. Methods: We included 113 consecutive adult patients with high risk hematological malignancies who underwent one-antigen MMUD (9/10-matched) bone marrow (BM) or peripheral blood (PB) HSCT after myeloablative or reduced-intensity conditioning at our institution from 2009-2013. Outcomes were compared between (a) conventional GVHD group (n=71) that received in-vivo T-cell depletion with ATG, tacrolimus and methotrexate and (b) PTCy group (n=41) that received PTCy (50 mg/kg/day IV on days 3 and 4) with tacrolimus and MMF. After exclusion of 29 patients with isolated HLA-DQ mismatches, a separate analysis was performed in 84 patients with 7/8 HLA-MUD HSCT; 38 patients received PTCy while 46 patients received conventional prophylaxis. Results: Patients in the conventional group were marginally older (median 54 years; range 19-74) than those in the PTCy group (median 50 years; range 20-64). PB was used more frequently as a graft source in the conventional group (38% vs 17%, p=0.02). PTCy group included more patients with HLA class-I mismatches (87.8%) compared to conventional group (56.9%). There were no other differences between the groups. Incidence of grade II-IV (37% vs 36%, p=0.8) or grade III-IV (17% vs 12%, p=0.5) acute GVHD at day 100 post-transplant was not different between the groups. [Figure 1] Incidence of grade II-IV acute GVHD at day 30 was significantly lower after PTCy compared with conventional prophylaxis (0% vs 15%, p