A Pilot Study: Identification and Reduction of Barriers for Unrelated Allogeneic Hematopoietic Stem Cell Transplantation in Patients with High-Risk Hematologic Malignancies

Abstract

The timeliness to Hematopoietic Stem Cell Transplant (HSCT) as a potential curative treatment for patients with high-risk hematologic malignancies such as acute leukemias, refractory disease, progressive disease, or other poor prognostic disease specific indications has been well established [3]. Timing is crucial from date of diagnosis, initiation of induction therapy, donor identification and transplantation. Any delay can provoke unfavorable patient outcomes and reinforces the critical need to reduce barriers for timeline to transplant [1]. Unrelated allogeneic HSCT pose greater risks due to the complexity of donor barriers versus match/mismatched related donor transplants [1]. Key factors resulting in delayed unrelated donor transplantation include; poor donor match probabilities – lack of ethnic minority populations or patients with rare allelic haplotype associations, low resolution Human Leukocyte Antigen (HLA) typing in donor registry, limited donor availability, lack of donor health history information, unknown infectious disease markers results, etc. [4]. Other potential areas for significant delay include time requirements for allele level HLA resolution, final donor selection and donor workup process. Given the high-risk patient population, identified existing donor barriers and finite window of opportunity for favorable HSCT outcomes; our center proposed a pilot study in conjunction with the National Marrow Donor Program (NMDP) to reduce barriers for rapid donor identification, selection and workup. The main objective of the proposed study was to identify and select a workup ready unrelated donor within 14 days of search initiation. Selected high-risk patients were enrolled in the pilot program from September 2016 through March 2018 (N = 25). Throughout the pilot study our center was able to identify areas of process improvement within our collective transplant program. Process improvements were also established in collaboration with the NMDP and their respective donor centers and collection centers. Following the completion of the study, we retrospectively analyzed our center's transplant data from 2017 and compared the time to transplant for pilot study patients (n = 15) versus all primary unrelated donor transplants (n = 100) performed, with the exclusion of cord blood unit transplants. We were able to obtain donor confirmatory typing appointments with a median of 7 days from formal search initiation. We were also able to reduce the median days for formal search to workup for the pilot study donors to 28 days versus 56 days, and the median days for formal search to donor collection to 35 days versus 97 days. Although we did not meet our proposed primary objective of 14 days, our center was able to successfully reduce the time needed to identify, select, and collect an unrelated donor for transplantation using the expedited process.