Abi Race: A prospective, multicenter study of black (B) and white (W) patients (pts) with metastatic castrate resistant prostate cancer (mCRPC) treated with abiraterone acetate and prednisone (AAP).

Abstract

LBA5009 Background: Pivotal trials of AAP for patients with mCRPC enrolled few B pts, a population with a higher mortality from prostate cancer. Retrospective data suggests B pts may have higher PSA response rates than W pts treated with AAP for mCRPC. Therefore, we prospectively investigated AAP in B vs. W pts with mCRPC. Methods: Abi Race (NCT01940276) is a prospective, multicenter, parallel group study of AP in 100 men (50 B, 50 W) with mCRPC, self-identified by race. All pts received AA 1000 mg/D and P 10 mg/D (AAP) until disease progression or unacceptable adverse events (AE). The primary objective was radiographic progression-free survival (rPFS); key secondary endpoints include PSA kinetics and safety. Exploratory analyses include SNP, metabolomics and hormonal differences by race. Results: Baseline characteristics among pts were similar. The median rPFS for B and W pts was 16.8 months (mo) in each. However, PSA PFS varied by race; median PSA PFS for B and W pts were 16.6 and 11.5 mo [Table]. B pts also had numerically higher rates of ≥30%, ≥50% and ≥90% PSA decline [Table]. AEs were similar in frequency and severity by race including hypertension (42 vs 40%); however, fatigue was higher in W pts (40 vs 26%), and hypokalemia was higher in B pts (36 vs 18%). SNP profiling revealed differences in key genes involved in androgen metabolism and transport. Conclusions: This is the first prospective multicenter study by race of secondary hormonal therapy in mCRPC. B pts may have greater and more durable PSA response to AAP than W pts. SNP patterns vary by race and will be evaluated for prognostic significance. Further prospective studies in B pts are possible and needed to understand the impact of racial determinants on outcome of new hormonal regimens. Clinical trial information: NCT01940276. [Table: see text]

Lack of Racial Survival Differences in Metastatic Prostate Cancer in National Cancer Data Base (NCDB): A Different Finding Compared to Non-metastatic Disease

“…Even though African American men had higher numbers of comorbidities, they still had better OS compared to white men (HR = 0.826; 95%CI [0.732-0.933]) (35). "Abi Race" (NCT01940276) is a prospective, multicenter study of African American and white patients with mCRPC treated with abiraterone acetate and prednisone, evaluating racial disparities in the outcomes (44). When George et al reported the initial results of this prospective study, they found the primary endpoint radiographic progression-free survival (rPFS) was equal among the races (16.8 months) (44).…”

“…“Abi Race” (NCT01940276) is a prospective, multicenter study of African American and white patients with mCRPC treated with abiraterone acetate and prednisone, evaluating racial disparities in the outcomes ( 44 ). When George et al reported the initial results of this prospective study, they found the primary endpoint radiographic progression-free survival (rPFS) was equal among the races (16.8 months) ( 44 ). Interestingly, African American men had more significant and more durable PSA progression-free survival, which was their secondary endpoint ( 28 ).…”

Geographic Distribution of Racial Differences in Prostate Cancer Mortality

“…3 Data from several clinical trials point in the same direction. George et al 16 reported that black men had better a progression-free survival rate compared with white men (16.6 months vs 11.5 months) when treated with abiraterone and prednisone. Moreover, a pooled analysis by Halabi et al 17 of 9 randomized clinical trials for advanced prostate cancer found that overall survival was the same for black and white men.…”

Association Between New Unconfirmed Bone Lesions and Outcomes in Men With Metastatic Castration-Resistant Prostate Cancer Treated With Enzalutamide

“…There was no pretreatment factor associated with the development of new unconfirmed lesions among men with mCRPC responding to enzalutamide in either setting. Although we originally hypothesized that men with more androgen-receptor-dependent prostate cancer, such as those with low Gleason scores, younger age, or African ancestry, [12][13][14] and those with fewer prior hormonal therapies would have a greater probability of pseudoprogression, baseline characteristics were similar in men with or without such new unconfirmed lesions detected on follow-up bone scans. Therefore, men who are likely to have pseudoprogression cannot presently be identified prospectively, and data suggest that all men be carefully observed over time for this phenomenon.…”