Disparities in Participation in Interventional Clinical Trials for Myelodysplastic Syndromes

Background: Only a minority of patients diagnosed with myelodysplastic syndromes (MDS) enroll in interventional clinical trials, which impedes development of novel therapies. Factors contributing to low trial accrual are incompletely understood but have been hypothesized to include the older age and frail nature of many patients with MDS, narrow trial eligibility criteria, lack of "precision medicine" agents, perception of MDS as an indolent or lower-risk disease, and difficulty or expense of traveling to trial centers (Steensma D et al Cancer 2018).

Methods: We analyzed a pooled patient database from institutions of the US MDS Clinical Research Consortium (MDS CRC) to compare characteristics of participants in interventional trials with those patients who never enrolled in a trial during their disease course. Demographics, ZIP code of patient residence (a surrogate measure for income), distance from home to the referral center, presenting blood counts, World Health Organization (WHO) 2008 MDS classification, and Revised International Prognostic Scoring System (IPSS-R) score were compared between trial participants and non-participants.

Results: Clinical trial enrollment data were available on 2,138 patients with MDS who had been evaluated at sites in the MDS CRC, of whom 515 (24.1%) participated in an interventional clinical trial. The median age of patients was 67.0 years and 63.4% were male. Patients who participated in trials were on average 1.2 years younger than non-participants (66.1 vs 67.3 years, p=0.037) while men were more likely to participate in a trial (70% of trial participants were male compared to 30% female, compare to non-participants of whom 61% were male and 39% female; p<0.01.) Clinical trial participants tended to live a little closer to the trial center (median distance 134.5 miles for participants vs. 154.8 miles for non-participants, p=0.15). Race was not associated with likelihood of trial enrollment, but Hispanic ethnicity was associated with trial non-participation (p=0.045) and patients in more affluent ZIP codes had a higher participation rate (p<0.01). Patients with RAEB-2, RCMD and RARS were over-represented in trials compared to disease subtype prevalence, while del(5q) was underrepresented (p=0.06). IPSS-R did not influence participation.

Conclusion: Even at large referral centers, only a minority of patients with MDS enroll in interventional trials. Younger, male, affluent non-Hispanic patients were more likely to enroll in studies. Understanding barriers to trial accrual may help investigators and study sponsors design trials that will accrue more rapidly and augment treatment options for patients with MDS.