Factors Associated With Clinical Trial Participation in Adult Hematopoietic Stem Cell Transplantation Recipients: A Center for International Blood and Marrow Transplant Research (CIBMTR) Analysis.

BACKGROUND

Only 3%-5% of patients with cancer nationwide enroll in clinical trials. Although participation among patients with solid tumors has been well studied, data in the hematopoietic stem cell transplantation (HSCT) setting remain limited. We sought to (1) describe clinical trial participation rates by HSCT type; (2) examine associations between patient, disease, and transplant characteristics and trial participation; and (3) explore the association between trial participation and overall survival (OS).

METHODS

We conducted a retrospective study using Center for International Blood and Marrow Transplant Research (CIBMTR) data from US adults aged 18-75 years who underwent autologous or allogeneic HSCT between 2013 and 2019 (N=84,151; autologous: n=51,133; allogeneic: n=33,018). Logistic regression models assessed predictors of participation, while Cox models evaluated associations with OS.

RESULTS

Trial participation was 2.0% among patients undergoing autologous HSCT and 11.1% among those undergoing allogeneic HSCT. Among autologous recipients, greater comorbidity burden was associated with lower odds of participation. Patients with multiple myeloma had higher odds than those with non-Hodgkin lymphoma (odds ratio [OR], 1.25; P=.01). Among allogeneic recipients, older adults had higher odds of participation (eg, OR, 2.19 for age ≥70 vs 18-19 years; P<.0001), as did non-Hispanic Black patients compared with non-Hispanic White patients (OR, 1.35; P=.0002). Participation was higher with cord blood grafts, mismatched unrelated donors, and certain diagnoses (eg, sickle cell disease). Lower participation was observed for severe aplastic anemia and haploidentical or peripheral blood grafts. Trial participation was not associated with OS in either group.

CONCLUSIONS

Clinical trial participation remains low, particularly among autologous HSCT recipients, younger adults, and patients with specific diagnoses. Findings highlight the need to broaden trial eligibility, enhance outreach, and ensure equity in trial access to promote generalizable, patient-centered evidence in HSCT.