Donor Search and Selection Strategy to Facilitate Comparable Transplant Rates across Donor Search Prognosis Groups: A Report from the BMT CTN 1702 Trial.

In a secondary analysis from the BMT CTN 1702 trial, we report on donor search and selection strategies according to baseline recipient search prognosis (SP). A total of 1751 patients in 3 SP groups-very likely, 958; less likely, 517; very unlikely, 276- were analyzed. The target time to HCT was most often 6 to 12 weeks (SP P = nonsignificant) and was associated with acute myelogenous leukemia remission status (P < .01). The baseline preferred alternative donor (across all SP groups was most commonly a haploidentical (haplo) donor (62.2% overall), whereas the use of mismatched unrelated donors (MMUDs) increased over time during the study period. Those in the less/very unlikely groups prioritized more alternative donor types at baseline and had more priority ranking changes (SP P < .01). While a comparable number of donors were typed (all SP: median, 3 donors; median time, 1.1 months), less/very unlikely SP had greater use of alternative donors (SP P < .01). Reasons for nonselection of typed donors varied by SP group. For less/very unlikely SP, the rates of HLA mismatching and donor-specific antibodies were higher, while for very likely SP, the use of other preferred donors was more common. Of 1751, 65% reached HCT: 94% of the very likely had an 8/8 matched unrelated donor (MUD) and 91% of the very unlikely had an alternative donor (haplo, 61%; MMUD, 22%; umbilical cord blood, 8%). HCT occurred within the initial desired timeline in 38% of all subjects. HCT delays occurred in 29%, mostly for disease or patient health overall, and of these 52% reached HCT after delay. In this prospective, multicenter evaluation of donor search and selection practices, we demonstrate that patients with poor likelihood of 8/8 MUD matching can reach HCT at comparable rates and with similar effort (time spent typing, number of donors typed) using an early alternative donor-centered strategy. Uniformly across SP groups, the target time to HCT is not commonly reached and is disrupted mostly by disease/patient health delays and not by donor unavailability.