Apalutamide may offer a survival advantage over abiraterone in patients with metastatic castration-sensitive prostate cancer (mCSPC), according to real-world data from the Flatiron Metastatic Prostate Cancer Core Registry. The retrospective ROMA study, presented at the 2024 Genitourinary Cancers Symposium, revealed that a higher proportion of androgen receptor signaling inhibitor (ARSI)-naive patients survived 24 months after initiating treatment with apalutamide compared to those treated with abiraterone acetate.
The study, which analyzed data from January 1, 2013, to May 31, 2023, included patients with chart-confirmed metastasis who started apalutamide or abiraterone treatment on or after September 17, 2019. Patients were followed for up to 24 months post-treatment initiation. The results indicated that 85.7% of patients in the apalutamide cohort were alive at 24 months, compared to 75.9% in the abiraterone acetate cohort, yielding an unadjusted hazard ratio of 0.60 (95% CI, 0.38-0.96; P = .033).
Key Findings from the ROMA Study
According to Neal Shore, MD, FACS, United States chief medical officer of surgery and oncology, GenesisCare USA, and director of the Carolina Urologic Research Center, the study corroborates earlier findings suggesting potential efficacy differences between pathway inhibitors and androgen biosynthesis ligand binding inhibitors. "Essentially, we observed that more treatment-naive patients with mCSPC survived by using apalutamide compared with abiraterone," Dr. Shore noted.
The median time on treatment was 11.4 months for the apalutamide cohort and 10.8 months for the abiraterone acetate cohort. Demographically, the age was balanced at around 73 years, and the proportion of White vs Black patients was also balanced, approximately 57% to 60% vs 14% to 17%.
Considerations and Future Research
While the ROMA study provides valuable real-world evidence, researchers caution that the comparisons are unadjusted, and further causal analyses are needed to account for comorbidities and other crossover therapies that could act as confounding factors. Nuances in medication administration, such as fed vs. non-fed state, prednisone use, and differing adverse event profiles, also warrant consideration.
"It always seems that the real gold standard would be a prospective, double-blind controlled trial as a direct comparator study for the different androgen receptor pathway drugs or AR-targeted agents," Dr. Shore commented. He highlighted the need for large, fully blinded studies to prospectively evaluate the performance of drugs like abiraterone, apalutamide, enzalutamide, and darolutamide.
Implications for Clinical Practice
The findings from the ROMA study offer clinicians additional evidence to consider during shared decision-making with their patients. The study suggests that apalutamide may lead to better survival rates than abiraterone in patients with mCSPC, although further research is necessary to confirm these findings and explore potential confounding variables.
