A prospective trial of apalutamide and abiraterone acetate plus prednisone in Black and White men with metastatic castrate-resistant prostate cancer.

Abstract

5015 Background: Abi Race was the first prospective parallel cohort study of abiraterone acetate plus prednisone (AAP) in Black and White men with metastatic castrate-resistant prostate cancer (mCRPC) and demonstrated greater prostate-specific antigen (PSA) response, time to PSA progression (TTP) and toxicity rates among Black patients (pts). We designed the PANTHER trial to estimate clinical outcomes among Black and White pts with mCRPC treated with apalutamide, abiraterone, plus prednisone. Methods: This parallel cohort multicenter study treated androgen receptor pathway inhibitor naïve mCRPC pts with oral apalutamide (240 mg/d), abiraterone (1000 mg/d) and prednisone (10 mg/d) (AAAP) continuously until disease progression, unacceptable toxicity or 2 years. The primary endpoint was radiographic progression free survival (rPFS); secondary endpoints were to estimate TTP, overall survival (OS) and best PSA response, among Black and White pts, separately. Exploratory endpoints included safety and correlative biomarkers of outcome by race and ancestry. Results: Between July 2017 and January 2021, we enrolled 43 Black and 50 White pts from 8 sites. Baseline prognostic characteristics were largely similar with some differences. We report an interim analysis as the pts are still followed for OS. At the time of the abstract submission, there were 18 and 36 rPFS events and 15 and 30 deaths in Black and White pts, respectively. We present the time to event endpoint rates at 12 and 24 mos and PSA declines for Black and White pts. Conclusions: We hypothesize that treatment with the combination of AAAP may result in clinical efficacy in Black men with mCRPC. Black pts were underrepresented in the phase III ACIS trial which compared AAP to AAAP and demonstrated longer rPFS but not OS. Further studies of AAAP combination therapy among Black men with advanced prostate cancer are needed to determine potential clinical benefits in this understudied population. Clinical trial information: NCT03098836 . [Table: see text]

The potential role of precision medicine to alleviate racial disparities in prostate, bladder and renal urological cancer care

“… 48 More recently, early results from the PANTHER trial, suggest Black men with mCRPCa also have a better response to combined abiraterone and apalutamide [an AR receptor inhibitor] with prednisolone than White men. 49 The efficacy of these treatments in other racial groups requires further study.…”

Advancing Equity in Cancer Research: Opportunities for Sponsors, Institutions, and Investigators

“…Despite the large sample size, and the racial disparities in prostate cancer where Black men carry the greatest burden in both incidence and mortality, no analyses were conducted by race due to inadequate representation. Recent studies have underscored the significance of having diverse representation in the studies, noting racial differences that would not be observed without adding a racial equity lens to their research questions and recruitment strategies that allow for race and ethnic analyses [13][14][15][16]. For example, a recent study explored the effects of a novel combination of hormonal therapies, Apalutamide and Abiraterone plus prednisone in patients with castrate-resistant prostate cancer and hypothesized that Black men may benefit more than White men [13].…”