Real-world clinical outcomes of apalutamide versus abiraterone with androgen deprivation therapy for metastatic hormone-sensitive prostate cancer

TL;DR

This study compares apalutamide and abiraterone in treating prostate cancer, finding apalutamide delays disease progression more effectively, though with more side effects.

Contribution

The study provides a direct comparison of apalutamide and abiraterone in mHSPC, focusing on PSA kinetics and survival outcomes.

Findings

Apalutamide showed significantly better PSA progression-free survival compared to abiraterone.

Apalutamide achieved lower median nadir PSA and faster time to reach it.

Adverse events were more common with apalutamide, but both treatments were generally well tolerated.

Abstract

Metastatic hormone-sensitive prostate cancer (mHSPC) is an aggressive disease with a poor prognosis. Current treatment guidelines recommend combining androgen receptor axis-targeted therapies (ARATs) with androgen deprivation therapy (ADT) for mHSPC. While individual ARATs have shown success, few studies directly compare their effects.

To compare the safety and clinical outcomes of abiraterone acetate (abiraterone) and apalutamide in chemotherapy-naïve mHSPC patients, focusing on prostate-specific antigen (PSA) kinetics, safety, and survival outcomes.

A retrospective, single-centre study included 107 chemotherapy-naïve mHSPC patients treated with abiraterone or apalutamide plus ADT. PSA levels were measured at baseline and during treatment. Primary outcomes were PSA progression-free survival (PSA-PFS) and overall survival (OS). Adverse events were recorded. Inverse probability treatment weighting adjusted baseline differences.

Median PSA-PFS significantly favoured apalutamide (log-rank p = 0.015). Achieving PSA ≤ 0.02 ng/mL was strongly associated with delayed progression (HR 0.07, 95% CI 0.02–0.28; p < 0.001). OS did not differ significantly between groups (p = 0.504). Apalutamide achieved lower median nadir PSA (0.02 ng/mL vs. 0.23 ng/mL, p < 0.001) and shorter mean time to nadir (4.5 vs. 7.2 months, p = 0.001), with more patients reaching ultralow PSA levels (≤ 0.02 ng/mL) during follow-up. Adverse events occurred more frequently with apalutamide (71.2% vs. 46.5%, p = 0.015), with fatigue and rash being the most common.

Apalutamide demonstrated deeper and more sustained PSA reductions, translating into delayed disease progression compared to abiraterone. Both treatments were generally well tolerated, though adverse events were more prevalent with apalutamide.

The online version contains supplementary material available at 10.1007/s11096-025-01920-4.

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