Prostate cancer is an immunotherapy responsive disease. Sipuleucel-T, an autologous cellular immunotherapy, demonstrated an improvement in overall survival (OS) in the phase 3 IMPACT (Identification of Men with a Genetic Predisposition to Prostate Cancer) trial, leading to US Food and Drug Administration approval in patients with asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC).1 Importantly, several analyses of survival by race suggest black men may see greater benefit from immunotherapy. In the IMPACT study, a greater survival benefit was seen in black men versus the overall population1; and now a retrospective, pooled analysis of 3 sipuleucel-T randomized studies by Quinn et al has demonstrated greater OS that was a statistically significant in black versus white men (hazard ratio, 0.49; 95% CI, 0.26-0.91; P=0.02).2

Also, an additional abstract from Thakur et al presented at the 2017 Genitourinary Cancers Symposium demonstrated that interferon γ enzyme-linked immunospots (ELISPOTs) were 2-fold higher in black men versus white men.3 These results suggest that there may be inherent differences associated with race, clinical response, and benefit of immunotherapies.

 Historically, black men have been underrepresented in phase 3 trials in prostate cancer. It will be important in the future to prioritize accrual of racially diverse populations in immunotherapy trials to understand if there are genetic or cellular differences associated with race and response to immunotherapy. It is possible that specific cellular, humoral, or inflammatory responses vary by race. These early studies support that hypothesis, which should be prospectively tested with control (ie, white)–matched populations.

 For clinicians today, these results reinforce the need to include standard treatment options such as sipuleucel-T in the management of black men with mCRPC. Although some patients may have access, cost, or religious constraints regarding treatments, it appears the clinical effects and benefits of immunotherapy are no worse, and may in fact be greater, for black men.