Disparities in the enrollment of racial and ethnic minorities in clinical trials of poly ADP ribose polymerase inhibitors for women's cancers

Objectives: Disparities persist in the enrollment of diverse racial and ethnic groups in clinical trials for ovarian and breast cancers. We sought to analyze the enrollment of participants by race/ethnicity in phase II and III clinical trials involving poly ADP ribose polymerase (PARP) inhibitors for ovarian and breast cancers and compare these to the racial/ethnic prevalence of ovarian and breast cancer in the United States. Methods: This study was designed as a retrospective review of clinical trials registered with Clinicaltrials.gov. Studies included evaluated PARP inhibitors for the treatment of ovarian, fallopian tube, primary peritoneal, and breast cancers. Enrollment rates for clinical trials were stratified by race/ethnicity and type of cancer. Enrollment fractions (EF) were calculated using prevalence data from the Surveillance, Epidemiology, and End Results (SEER) Database. Odds ratios (OR) and 95% Confidence Intervals (CI) were calculated to compare minority enrollment rates to Non-Hispanic (NH) White enrollment rates. Results: A 48 trials were identified, 17 of which met inclusion criteria (12 ovarian, 2 breast and 3 breast and ovarian). For ovarian cancer trials, enrollment fractions were NH-White 1.5%, NH-Black 0.3%, Hispanic 0.5%, and Asian/Pacific Islander the largest at 2.4%. For breast cancer trials, the EF for NH-White participants was 0.005%, for NH-Black patients was 0.008%, for Hispanic patients was 0.003%, and for Asian/Pacific Islander patients, still the highest at 0.009%. Patients identified as NH-Black and Hispanic were significantly underrepresented compared to those identified as NH-White in clinical trials for ovarian cancer (OR 0.23, 95% CI [0.18-0.29] and OR 0.3, 95% CI [0.25-0.38] respectively, p-value of Download : Download high-res image (215KB) Download : Download full-size image Conclusions: NH-Black and Hispanic participants are significantly underrepresented in clinical trials evaluating PARP inhibitors for ovarian cancer compared to NH-White cohorts. Phase II and III trials assessing PARP inhibitors for ovarian and breast cancer 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.