Real-world Efficacy and Safety of Low-Dose Abiraterone With Food and Standard-Dose Abiraterone in De Novo Metastatic Hormone-Sensitive Prostate Cancer: A Retrospective Analysis.

Background: The standard treatment for de novo metastatic hormone-sensitive prostate cancer (mHSPC) involves androgen deprivation therapy (ADT) combined with next-generation hormonal agents and/or docetaxel. While the standard dose (STD) of abiraterone is 1,000 mg administered while fasting, recent evidence suggests that a low dose (LOW) of 250 mg taken with a low-fat meal may achieve comparable pharmacokinetic outcomes.

Objectives: This study aimed to evaluate the failure-free survival (FFS) and safety of LOW and STD in de novo high-risk mHSPC patients.

Materials And Methods: We conducted a retrospective analysis of males with de novo high-risk mHSPC treated with ADT plus abiraterone (250 mg with a low-fat meal or 1000 mg fasting) at the Vietnam National Cancer Hospital from January 2019 to May 2024. The primary endpoint was FFS, assessed using Kaplan-Meier and multivariate Cox regression analyses.

Results: The study included 183 patients, with 91 in the LOW group and 92 in the STD group. The rates of patients who achieved undetectable PSA (PSA < 0.2 ng/ml) were 52.7% in the LOW group and 47.8% in the STD group. The median time to undetectable PSA was 6.9 months in the LOW group and 6.4 months in the STD group. The median overall FFS was 28.1 months (95% CI: 21.1 to 35.0) in the LOW group and 25.4 months (95% CI: 15.5 to 35.3) in the STD group (P = .286). Multivariate analysis indicated that visceral metastases and detectable PSA (PSA ≥ 0.2 ng/ml) were significant negative predictors of FFS in both groups. The incidence of grade 3 and grade 4 adverse events was similar between the LOW group and the STD group.

Conclusions: The LOW group and STD group showed effectiveness and safety in de novo high-risk mHSPC. The use of low-dose abiraterone in de novo mHSPC can significantly reduce treatment costs.