Sex, racial, and ethnic disparities in motor neuron disease: clinical trial enrolment.

Objective: Motor neuron disease (MND) is a group of neurological diseases, the majority being amyotrophic lateral sclerosis (ALS), with varying clinical presentations across demographics. Clinical trial enrollment reflecting global disease burden improves understanding of diverse presentations and aids personalized therapy development. We assessed the sex, racial, and ethnic composition of MND/ALS clinical trial participants relative to global disease burdens.

Methods: We searched 'motor neuron disease OR amyotrophic lateral sclerosis' on ClinicalTrials.gov from 02/2000-04/2024. We extracted trial (start year, study site, sponsor location, phase, masking, intervention) and demographic data (sex, race, ethnicity) from randomized interventional studies. We obtained sex-based MND/ALS disease burden estimates from the Global Burden of Disease database. For females, we calculated pooled participation-to-prevalence ratio (PPR) with 95% confidence intervals (CIs), with PPR of 0.8-1.2 indicating adequate enrollment. We used Kruskal-Wallis tests to compare demographic groups across trial characteristics.

Results: Of 85 trials, females comprised 37.47% (n = 5011) of 13,372 participants; the pooled female PPR was 0.97 (95% CI: 0.77-1.16). Of 41 trials (9340 participants) reporting race, 121 (1.30%) participants were Black or African American, 16 (0.17%) American Indian or Alaskan Native, and 6 (0.06%) Native Hawaiian or Other Pacific Islander. 24 trials (595 participants) reported ethnicity, with a minority of Hispanic participants (n = 153; 2.57%).

Conclusions: MND/ALS clinical trials had adequate female enrollment relative to global disease burdens. Race and ethnicity data were underreported. However, there were enrollment disparities of racial and ethnic groups. Increased trial leadership diversity, equitable enrollment policies, and addressing barriers to participation could improve enrollment diversity.