Registry Efforts to Improve Success of Unrelated Donor Searching for African American Patients

Abstract

s / Biol Blood Marrow Transplant 21 (2015) S266eS321 S292 disease progression [n1⁄463, median time1⁄40.36 yrs, range1⁄40.09-9.01yrs] had a significant impact on OS [p<0.01] and EFS [p<0.01]. Notably, treatment with any chemotherapy prior to receiving a DLI did not significantly impact OS [p1⁄40.22] or EFS [p1⁄40.54]. Our analysis reveals no difference in OS or EFS between the use of fresh or cryopreserved cells for DLI. There is a trend to favor fresh cell DLI in patients who have undergone a nonmyeloablative transplant. Our study confirmed previous observations that a greater interval between original transplant and relapse correlates with greater DLI success.We also highlight that in the setting of relapsed disease, pretreatment with chemotherapy did not impact post-DLI OS or EFS. In conclusion, selected patients can achieve long term survival with DLI for post-transplant relapse though the overall outcomes remain dismal. Figure 1. Time to transplant from preliminary search Figure 2. Cumulative incidence probability of transplant with an adult unrelated donor with CBU transplant as a competing risk 415 Registry Efforts to Improve Success of Unrelated Donor Searching for African American Patients Katie A. Howe , Kevin Tram, Beth Beduhn , Rachel Fonstad , Deidre M. Kiefer , Jason Dehn . National Marrow Donor Program, Minneapolis, MN; 2 Center for International Blood and Marrow Transplant Research, National Marrow Donor Program, Minneapolis, MN African American (AFA) patients are an underserved race group in bone marrow transplant due to their diverse HLA, limited number of potential unrelated donors (URD) and low URD availability rates. Newly entered AFA patients who had Be The Match Registry searches of intermediate difficulty were enrolled in this blind randomized study to determine if proactive URD contact and HLA typing would (1) increase patient transplant rates (2) increase selection of an URD over a cord blood unit (CBU). We examined incoming patients from Feb to Oct of 2013 to identify and enroll a subset of AFA searches who had 10 potential 8/8 URD with HapLogic allele matching prediction of 31% or zero 8/8 with 10 7/8 URD with matching prediction of 76%. Searches were randomized 1:1 into two arms; 182 to intervention and 178 to no intervention. In the intervention arm, HLA specialists reviewed 182 patient searches and selected 2473 URD for contact to confirm availability with 591 available URD HLA typed (up to 20 URD/ patient). Patient searches were excluded from the study if they had “unproductive”URD search results (i.e. no URDwith at least a 2% chance of being 7/8) or had “very productive” URD search results (i.e. 11 URD with 31% prediction of being an 8/8 or zero potential 8/8 URD with 10 URD with 75% prediction of being a 7/8). URD were high-resolution typed at HLA-A, B, C, DRB1 and DQB1, and the transplant center was notified when an available 7/8 or better matched URD was identified for consideration. Patient cases were followed for URD or CBU transplant endpoints up to 1 year post initial search submission. Descriptive statistics for the two randomized arms were similar in patient age, disease (malignant vs non-malignant), and URD search productivity. 217matched and available URD notifications were sent to transplant centers on behalf of 115 patients. Although not achieving statistical significance, intervention patients progressed to transplant 20% of the time vs. 15% in the non-intervention group at 1 year (Figure 1) and transplanted more oftenwith an URD over a CBU, 63% vs. 48%, respectively. At 1 year, the intervention group progressed to URD transplant in 12% of cases compared to 7% in the non-intervention group (Figure 2) and CBU transplant in 7% of intervention cases vs. 8% in the non-intervention group. AFA searches not meeting the inclusion criteria for study randomization were also examined. Very productive potential 8/8 URD searches resulted in transplant 27% of the time (88% chose an URD) and searches containing zero 8/8 URD with many potential 7/8 URD resulted in transplant 19% of the time (44% chose an URD). Patients that had zero potential 7/8 donors with at least 2% likelihood to match only went to transplant 2% of the time. Additional registry URD contact and HLA typing efforts for challenging AFA patient searches may clarify the search options available and assist transplant decision making.