SUMMARY

• PANTHER (NCT03098836), a phase 2, prospective, open-label, multicenter, parallel-cohort study, evaluated the efficacy and safety of ERLEADA plus abiraterone acetate with prednisone (AAP) in patients with metastatic castration-resistant prostate cancer (mCRPC) stratified by race (Black, n=43; White, n=50). The primary endpoint was radiographic progression-free survival (rPFS), and secondary endpoints included time to prostate-specific antigen (PSA) progression, overall survival (OS), and PSA response.^1,2
  • In the long-term efficacy analysis, after a median follow-up of 56 months vs 62 months in Black vs White patients, the 24-month rPFS rate was 61% (95% CI, 49-78) vs 38% (95% CI, 27-54), and the 36-month OS rate was 68% (95% CI, 55-83) vs 50% (95% CI, 37-66; Table: Efficacy Outcomes in Black and White Patients in the PANTHER Study).
  • In an analysis evaluating the association of baseline serum steroid hormone levels with treatment outcomes by race in patients from the PANTHER (n=86) and Abi Race (n=75) studies, the baseline dehydroepiandrosterone sulfate (DHEAS) levels below the median were associated with a trend towards shorter rPFS (HR 1.54; 95% CI, 0.87-2.73) and OS (HR 1.14; 95% CI, 0.67-1.95) in the PANTHER study (Table: Baseline DHEAS Levels and Clinical Outcomes in Black and White Patients in the PANTHER Study).³ 
  • In an analysis evaluating the association of expression of distinct ceramide species with outcomes by race (Black, n=28; White, n=37), ceramide (d18:1/20:0) levels were associated with prolonged rPFS (HR 4.02; 95% CI, 1.06-15.2; P=0.041) and OS (HR 4.82; 95% CI, 1.51-15.4; P=0.008) among Black patients.⁴ 
• Additionally identified in the literature was an analysis of serum androgen level suppression in enrolled patients of the PANTHER study, by measuring abiraterone acetate, its metabolites, and androgens (n=86).⁵ 

CLINICAL DATA

George et al (2024)¹ and (2023)² reported results of the PANTHER study evaluating the efficacy and safety of ERLEADA and AAP in patients with mCRPC stratified by race (Black, n=43; White, n=50).

Study Design/Methods

• Phase 2, prospective, open-label, multicenter, parallel-cohort study (Figure: PANTHER Study Design)

Results

Patient Characteristics

• Key baseline characteristics for each cohort are summarized in Table: Select Baseline Patient Characteristics.

Efficacy

• Efficacy outcomes for both cohorts are summarized in Table: Efficacy Outcomes in Black and White Patients in the PANTHER Study. In the long term efficacy analysis, the median follow-up was 56 months and 62 months for the Black and White cohorts, respectively.

Safety

• Safety results were not reported.

George et al (2025)³ reported the association of baseline serum steroid hormone levels with treatment outcomes by race in patients from the PANTHER and Abi Race studies.

Study Design/Methods

• Serum levels of 12 steroid hormones were measured using LC/MS-MS in samples collected at baseline and week 4 from 161 patients (PANTHER, n=86; Abi Race, n=75).
• Median levels for each hormone were calculated combining both study populations and used as a cut point.

Results

• The median baseline DHEAS level was 49 mg/dL. The median baseline DHEAS levels in Black vs White patients were 52 mg/dL (range 7-248) vs 42 mg/dL (range 4-220).
• The baseline DHEAS levels below the median were associated with a trend towards shorter rPFS (HR 1.54; 95% CI, 0.87-2.73) and OS (HR 1.14; 95% CI, 0.67-1.95) in the PANTHER study.
• The association between baseline DHEAS levels and clinical outcomes in Black and White patients in the PANTHER study is summarized in Table: Baseline DHEAS Levels and Clinical Outcomes in Black and White Patients in the PANTHER Study.

Literature Search

A literature search of MEDLINE^®, Embase^®, BIOSIS Previews^®, and Derwent Drug File (and/or other resources, including internal/external databases) was conducted on 12 May 2025.