Racial and ethnic enrollment disparities in clinical trials of poly(ADP-ribose) polymerase inhibitors for gynecologic cancers.

Objectives: Disparities persist in the enrollment of racial/ethnic groups in clinical trials for ovarian cancers. We sought to analyze the enrollment rates of patients by race/ethnicity in phase II/III clinical trials involving poly(ADP-ribose) polymerase (PARP) inhibitors for ovarian cancers and compare these to the racial/ethnic prevalence of ovarian cancers in the United States.

Methods: This study was a retrospective review of clinical trials registered with ClinicalTrials.gov. Studies included evaluated PARP inhibitors for the treatment of ovarian, fallopian tube, and primary peritoneal cancers. Enrollment rates for clinical trials were stratified by race/ethnicity and type of cancer. Enrollment fractions (EFs) were calculated using prevalence data from the Surveillance, Epidemiology, and End Results Program. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to compare racial/ethnic group enrollment rates to Non-Hispanic (NH) White enrollment rates.

Results: Forty-eight trials were identified, 15 of which met inclusion criteria. The EFs for included trials, were 1.5% for NH-White, 0.47% for NH-Black, 0.33% for Hispanic, and 2.38% for Asian/Pacific Islander. Patients who identified as NH-Black and Hispanic were significantly underrepresented compared to those who identified as NH-White (OR 0.23, 95% CI [0.18-0.29] and OR 0.3, 95% CI [0.25-0.38] respectively, p < 0.001).

Conclusions: NH-Black and Hispanic patients are significantly underrepresented in clinical trials evaluating PARP inhibitors for ovarian cancers compared to NH-White cohorts. Phase II/III trials assessing PARP inhibitors for ovarian cancers do not accurately represent the populations diagnosed with these malignancies. Enrollment strategies are needed to increase diversity in PARP inhibitor clinical trials for women's cancers.