Adams‐Campbell, Lucile L.

LBA12004 Background: Hot flashes are among the most common adverse events impacting quality of life reported by patients receiving androgen deprivation therapy (ADT) for the treatment of prostate cancer. Oxybutynin is an effective therapy for reducing frequency and severity of hot flashes in women. Pilot information supports that this drug may also benefit men with hot flashes related to ADT. Methods: Patients with prostate cancer receiving a stable regimen of ADT with at least 28 hot flashes per week were randomized to receive either oral oxybutynin 2.5 mg twice a day, oxybutynin 5 mg twice a day, or matching placebo doses for 6 weeks. The primary endpoint was the change in patient-reported hot flash scores (determined by multiplying the number of hot flashes by the mean hot flash severity [grade 0: none, 1: mild, 2: moderate, 3: severe, and 4: very severe]) from baseline to 6 weeks, as measured by a daily hot flash diary. A total of 87 patients provided 76% power to reject the null hypothesis of no between-arm mean difference in hot flash score reduction from baseline to 6 weeks, when comparing each oxybutynin arm to the combined placebo arms. This was based on a two-sided contrast estimated from a generalized linear mixed model, α= 0.10, intraclass correlation of 0.50, population standardized mean difference of 0.50, and 10% missing data rate. Results: 88 patients were accrued between 10/28/21 and 12/02/23. Six patients cancelled before starting treatment and one was ineligible, leaving 81 analyzed patients with a median age of 68. Baseline characteristics were balanced between arms with patients reporting an average of 10.15 (SD = 5.55) hot flashes per day and an average daily hot flash score of 18.23 (SD = 13.48) at enrollment. On average, patients on the placebo arm, low dose oxybutynin arm, and high dose oxybutynin arm had reductions of 2.15, 4.77, and 6.89 hot flashes/day, respectively. Compared to placebo arm patients, high dose oxybutynin arm patients had a greater reduction in hot flashes/day (p < 0.001), as did low dose oxybutynin arm patients (p = 0.02). Daily hot flash scores for the same three protocol arms reduced by an average of 4.85, 9.94, and 13.95 points, respectively. Compared to placebo arm patients, high dose oxybutynin arm patients had a greater reduction in daily hot flash scores (p = 0.002), as did low dose oxybutynin arm patients (p = 0.07). No treatment-related grade 3+ adverse events occurred. The most commonly reported oxybutynin-related grade 2 adverse event was dry mouth. Conclusions: Oxybutynin is superior to a placebo for the management of hot flashes in men associated with androgen deprivation therapy and appears to be well tolerated. Support: UG1CA189823; https://acknowledgments.alliancefound.org . Clinical trial information: NCT04600336 .

6509 Background: Accrual of underrepresented populations (URPs-racial and ethnic minorities, women, rural populations, and younger and older populations) to clinical trials has been historically low, hampering progress in cancer treatment, symptom intervention and prevention for all. In 2018, the Alliance for Clinical Trials in Oncology (Alliance), as a part of the NCI's National Clinical Trials Network (NCTN) and a Research Base for the NCI Community Oncology Research Program (NCORP) began a multi-pronged strategy to increase accrual of underrepresented minorities by race and ethnicity (URMs) to both treatment and cancer control trials conducted by the Alliance. Methods: Alliance leadership set a goal of 20% accrual for racial and ethnic minorities to all trials in 2018. The Health Disparities Committee (HDC) implemented several strategies over time including leadership promotion/expectation of goals; funding junior investigators and special projects focusing on URPs; working groups for specific populations in HDC; HDC co-chairs to selected protocols; translation services of patient facing materials; opening studies at NCORP Minority Underserved Sites; real time monitoring of accrual demographics, by Alliance and by site; protocols addressing aims for specific populations; closing protocol enrollment to majority populations; and increasing the study sample size to enroll additional minority participants to allow for analyzing intervention effects by subgroups. Results: Accrual data from 117 NCTN and NCORP trials led by Alliance was included from 2014-2022. Over time, accrual of racial and ethnic minorities increased from 13.6% to 25.3% for treatment and 13% to 21.5% for cancer control trials. This results in overall increase from 13.5 % to 23.6% of URMs for all trials, a 74.8% improvement. Conclusions: Intentional approaches to increase URMs has led to an increase in URM accruals to Alliance trials. Future strategies include implementation of the Alliance Patient Questionnaire to prospectively measure the prevalence of specific social determinants of health among patients enrolled to further expand the understanding and address the needs of unique population accrued to Alliance trials. In addition, accrual of women, rural populations, and younger and older adults (65+ years) are now being monitored over time to increase all URP accruals.