Urbano-Ispizúa, Álvaro

Abstract Abstract 3094 The HLA class II DRB1 antigen DR15 is an important immunobiologic marker in immune mediated marrow failure states. DR15 has also been reported in small studies to be associated with favorable outcomes (reduction in acute GVHD and reduced relapse resulting in improved overall survival) after allogeneic hematopoietic cell transplant. To elucidate the impact of DR15 on major transplant outcomes, we conducted a retrospective study of 2, 891 recipients of first marrow or mobilized peripheral blood stem cell transplantation for the treatment of acute myeloid leukemia (n=1038), acute lymphoblastic leukemia (n=700), chronic myeloid leukemia (n=948), or myelodysplastic syndrome (n=205) between 1990–2008 and reported to the CIBMTR registry. Selection was confined to HLA-identical sibling transplantation to avoid HLA-disparity as a driving force for observed differences. All patients received conventional myeloablative conditioning, T-replete grafts and cyclosporine plus methotrexate- based GVHD prophylaxis. DNA-based HLA typing allowed categorization of 732 (25.3%) patients as positive and 2159 (74.7%) patients as negative for DRB1*15 :01 or *15 :02 (DR15). There were no significant differences in baseline characteristics between the HLA DR15-positive and -negative groups. In univariate analysis, HLA-DR15 status had no impact on neutrophil engraftment, acute graft-versus-host disease (GvHD) II-IV or III-IV, chronic GVHD, treatment related mortality, relapse, disease-free survival or overall survival. Confining the univariate analysis to myeloid malignancies did not alter these findings. Multivariate analysis models were constructed with DR15 status forced into the models in all steps of model building and the final model regardless of its statistical significance. Other variables tested included: donor/recipient age, CMV status, disease, disease stage, graft source, Karnofsky score, race and year of transplant. Variables that attained a p-value ≤0.05 were held in the final multivariate models. In multivariate analysis, DR15 status showed no significant difference in the primary outcomes of acute GVHD II-IV or III-IV, chronic GVHD, overall survival, or relapse. In conclusion, DR15 status had no impact on major HLA-matched sibling donor hematopoietic cell transplantation outcomes in this large and homogenous cohort of leukemia and MDS patients. Disclosures: No relevant conflicts of interest to declare.

Key Points Compared with parous female sibling donors, male URDs confer more aGVHD in all patients and more cGVHD in females. There was no difference in survival, relapse, or transplant mortality between recipients of parous female sibling or male URD grafts.

BACKGROUNDEarly treatment failure (ETF) in follicular lymphoma (FL), defined as relapse or progression within 2 years of frontline chemoimmunotherapy, is a newly recognized marker of poor survival and identifies a high‐risk group of patients with an expected 5‐year overall survival (OS) rate of approximately 50%. Transplantation is an established option for relapsed FL, but its efficacy in this specific ETF FL population has not been previously evaluated.METHODSThis study compared autologous hematopoietic stem cell transplantation (auto‐HCT) with either matched sibling donor (MSD) or matched unrelated donor (MUD) allogeneic hematopoietic cell transplantation (allo‐HCT) as the first transplantation approach for patients with ETF FL (age ≥ 18 years) undergoing auto‐HCT or allo‐HCT between 2002 and 2014. The primary endpoint was OS. The secondary endpoints were progression‐free survival, relapse, and nonrelapse mortality (NRM).RESULTSFour hundred forty FL patients had ETF (auto‐HCT, 240; MSD hematopoietic stem cell transplantation [HCT], 105; and MUD HCT, 95). With a median follow‐up of 69 to 73 months, the adjusted probability of 5‐year OS was significantly higher after auto‐HCT (70%) or MSD HCT (73%) versus MUD HCT (49%; P = .0008). The 5‐year adjusted probability of NRM was significantly lower for auto‐HCT (5%) versus MSD (17%) or MUD HCT (33%; P < .0001). The 5‐year adjusted probability of disease relapse was lower with MSD (31%) or MUD HCT (23%) versus auto‐HCT (58%; P < .0001).CONCLUSIONSPatients with high‐risk FL, as defined by ETF, undergoing auto‐HCT for FL have low NRM and a promising 5‐year OS rate (70%). MSD HCT has lower relapse rates than auto‐HCT but similar OS. Cancer 2018;124:2541‐51. © 2018 American Cancer Society.

Abstract Risk factors for acute GVHD (AGVHD), overall survival, and transplant-related mortality were evaluated in adults receiving allogeneic hematopoietic cell transplants (1999-2005) from HLA-identical sibling donors (SDs; n = 3191) or unrelated donors (URDs; n = 2370) and reported to the Center for International Blood and Marrow Transplant Research, Minneapolis, MN. To understand the impact of transplant regimen on AGVHD risk, 6 treatment categories were evaluated: (1) myeloablative conditioning (MA) with total body irradiation (TBI) + PBSCs, (2) MA + TBI + BM, (3) MA + nonTBI + PBSCs, (4) MA + nonTBI + BM, (5) reduced intensity conditioning (RIC) + PBSCs, and (6) RIC + BM. The cumulative incidences of grades B-D AGVHD were 39% (95% confidence interval [CI], 37%-41%) in the SD cohort and 59% (95% CI, 57%-61%) in the URD cohort. Patients receiving SD transplants with MA + nonTBI + BM and RIC + PBSCs had significantly lower risks of grades B-D AGVHD than patients in other treatment categories. Those receiving URD transplants with MA + TBI + BM, MA + nonTBI + BM, RIC + BM, or RIC + PBSCs had lower risks of grades B-D AGVHD than those in other treatment categories. The 5-year probabilities of survival were 46% (95% CI, 44%-49%) with SD transplants and 33% (95% CI, 31%-35%) with URD transplants. Conditioning intensity, TBI and graft source have a combined effect on risk of AGVHD that must be considered in deciding on a treatment strategy for individual patients.