Phase II Trial of Abiraterone Acetate Plus Prednisone in Black Men With Metastatic Prostate Cancer
Che-Kai Tsao, John Sfakianos, Bobby Liaw, Kiev Gimpel-Tetra, Margaret Kemeny, Linda Bulone, Mohammad Shahin, William Kyu Oh, Matthew David Galsky, Che-Kai Tsao, John Sfakianos, Bobby Liaw, Kiev Gimpel-Tetra, Margaret Kemeny, Linda Bulone, Mohammad Shahin, William Kyu Oh, Matthew David Galsky
Abstract
Lessons learned: The safety and activity findings of abiraterone acetate plus prednisone treatment in black men with mCRPC were similar to results from previously conducted studies with largely white populations.Poor trial accrual continues to be a challenge in black men with mCRPC and further efforts are needed to address such underrepresentation.
Background: Self-identified black men have higher incidence and mortality from prostate cancer in the United States compared with white men but are dramatically underrepresented in clinical trials exploring novel therapies for metastatic castration-resistant prostate cancer (mCRPC).
Methods: Black men with mCRPC were treated with abiraterone acetate (AA), 1,000 mg daily, and prednisone (P), 5 mg twice daily. The primary objective was to determine antitumor activity (defined by a ≥30% decline in prostate-specific antigen [PSA] level) and to correlate germline polymorphisms in androgen metabolism genes with antitumor activity. Secondary objectives included determining safety, post-treatment changes in measurable disease, and time to disease progression.
Results: From April 2013 to March 2016, a total of 11 black men were enrolled and received AA plus P (AA+P); 7 of 10 evaluable patients were docetaxel naive. Post-treatment declines in PSA level of ≥30% were achieved in 90% of patients. The side effect profile was consistent with prior clinical trials exploring AA+P in mCRPC. Due to poor accrual, the study was closed prematurely with insufficient sample size for the planned pharmacogenetic analyses.
Conclusion: In this small prospective study terminated for poor accrual, the safety and activity of AA+P in black men with mCRPC was similar to that reported in prior studies exploring AA in largely white populations. Further efforts are needed to address underrepresentation of black men in mCRPC trials.
Trial registration: ClinicalTrials.gov NCT01735396.
©AlphaMed Press; the data published online to support this summary is the property of the authors.
Figures
References
- de Bono JS, Logothetis CJ, Molina A, et al. Abiraterone and increased survival in metastatic prostate cancer. N Engl J Med. 2011;364:1995–2005.
- Ryan CJ, Smith MR, de Bono JS, et al. Abiraterone in metastatic prostate cancer without previous chemotherapy. N Engl J Med. 2013;368:138–148.
- Ross RW, Oh WK, Xie W, et al. Inherited variation in the androgen pathway is associated with the efficacy of androgen-deprivation therapy in men with prostate cancer. J Clin Oncol. 2008;26:842–847.
- Yang M, Xie W, Mostaghel E, et al. SLCO2B1 and SLCO1B3 may determine time to progression for patients receiving androgen deprivation therapy for prostate cancer. J Clin Oncol. 2011;29:2565–2573.
- Sarma AV, Dunn RL, Lange LA, et al. Genetic polymorphisms in CYP17, CYP3A4, CYP19A1, SRD5A2, IGF-1, and IGFBP-3 and prostate cancer risk in African-American men: The Flint Men’s Health Study. Prostate. 2008;68:296–305.
- Rivers D, August EM, Sehovic I, et al. A systematic review of the factors influencing African Americans’ participation in cancer clinical trials. Contemp Clin Trials. 2013;35:13–32.
- Adams-Campbell LL, Ahaghotu C, Gaskins M, et al. Enrollment of African Americans onto clinical treatment trials: Study design barriers. J Clin Oncol. 2004;22:730–734.
- Spratt DE, Osborne JR. Disparities in castration-resistant prostate cancer trials. J Clin Oncol. 2015;33:1101–1103.
Source: PubMed