Low-Dose Abiraterone Noninferior for Castration-Resistant PCa
Low-dose AA with low-fat breakfast had greater effect on PSA; similar effect to standard dose
(HealthDay News) -- For castration-resistant prostate cancer (CRPC), low-dose abiraterone acetate (AA) with a low-fat breakfast is noninferior to standard dose with fasting in terms of the mean change in prostate-specific antigen (PSA), according to a study published online in the Journal of Clinical Oncology.
Russell Z. Szmulewitz, MD, from the University of Chicago, and colleagues randomized 72 patients with progressive CRPC to low-dose AA (LOW; 250 mg with low-fat meal) with standard AA (STD; 1000 mg fasting). PSA was assessed monthly; every 12 weeks, testosterone/dihydroepiandrosterone sulfate were assessed with radiographic assessments of disease burden.
The researchers observed a greater effect on PSA in the LOW arm vs the STD arm (mean log-change, −1.59 versus −1.19); according to predefined criteria, the noninferiority of LOW was established. The PSA response rate was 58 and 50% in LOW and STD groups, respectively; in both groups, median progression-free survival was about 9 months. In both arms there was a similar decrease in androgen levels. Abiraterone concentrations were higher in the STD group, although there was no difference in PSA response or progression-free survival.
"Low-dose AA (with low-fat breakfast) is noninferior to standard dosing with respect to PSA metrics," the authors write. "Given the pharmacoeconomic implications, these data warrant consideration by prescribers, payors, and patients."
Szmulewitz RZ, Peer CJ, Ibraheem A, et al. Prospective International Randomized Phase II Study of Low-Dose Abiraterone With Food Versus Standard Dose Abiraterone In Castration-Resistant Prostate Cancer. J Clin Oncol.