There was little difference in outcomes between Black and non-Black prostate cancer patients treated with the androgen receptor inhibitor darolutamide, according to data presented at the 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved (Abstract PR-07).
The ARAMIS Phase III clinical trial was designed to evaluate the efficacy and safety of darolutamide compared with placebo in combination with androgen deprivation therapy in patients with high-risk nonmetastatic castration-resistant prostate cancer.
Unlike other androgen receptor inhibitors, darolutamide exhibits low penetration of the blood-brain barrier and, therefore, may be associated with less risk of adverse events of the central nervous system, explained Neal Shore, MD, Medical Director of the Carolina Urologic Research Center, in Myrtle Beach, SC.
Higher incidence and mortality rates of prostate cancer have been observed in Black and African-American men (B/AAs) compared with other racial and ethnic groups. B/AAs with prostate cancer are more likely to be diagnosed at a younger age with more extensive disease and exhibit differential gene expression associated with more aggressive disease, but they are less likely to receive therapy compared with White men.
"Compared with other racial and ethnic groups, Black/African-American individuals have disproportionately higher rates of prostate cancer incidence and mortality," he told a press briefing. "Despite this disparity, many clinical trials of prostate cancer therapies fail to publish demographic information on race and ethnicity."
In addition to lower penetration of the blood-brain barrier, he noted that darolutamide has low potential to interact with other common medications.
Shore and his colleagues have previously reported that darolutamide significantly improved metastasis-free survival and overall survival, and exhibited a favorable safety profile, in patients enrolled in the ARAMIS trial. The latest data comes from an analysis evaluating the safety and efficacy of darolutamide specifically among Black/African-American patients enrolled in the trial.
Among the 52 Black/African-American patients included in the analysis, 28 were treated with darolutamide, and 24 received placebo. Patients treated with darolutamide had longer metastasis-free survival (median not reached in the darolutamide arm vs. 12.4 months) and a higher 3-year overall survival rate (100% vs. 71%) compared with those who received placebo.
Treatment with darolutamide also resulted in longer time to first cytotoxic chemotherapy and longer time to disease progression. In addition, the safety profile among Black/African-American patients was consistent with the results from the overall study population. The incidence of adverse events (82% vs. 92%) and treatment discontinuation due to adverse events (4% vs. 17%) was lower for darolutamide-treated patients compared with placebo-treated patients.
"Darolutamide showed similar benefits for Black/African-American patients as observed in the overall ARAMIS population," said Shore. "Our study provides important findings that help to address the lack of data in Black/African-American patients who are disproportionally affected by prostate cancer. Additional research is warranted to better understand the disparity in outcomes in these patients and help guide treatment choices tailored to their individualized health care needs."
A limitation of the study was the small sample size of Black/African-American patients enrolled in the ARAMIS trial. "In future clinical trials, we need to improve participation of underrepresented populations through such efforts as building trust in the health care system, utilizing patient advocates, and increasing awareness and educational opportunities," he noted.
Kurt Samson is a contributing writer.