Pharmacoeconomic Implications of Low-Dose Abiraterone in Castration-Resistant Prostate Cancer
Posted: Wednesday, August 15, 2018
A team of investigators from the University of Chicago sought to determine whether low-dose abiraterone would have comparable activity to standard abiraterone in patients with metastatic castration-resistant prostate cancer. What they discovered was that low-dose abiraterone (250 mg with a low-fat meal) was noninferior to standard dosing (1,000 mg fasting) with respect to prostate-specific antigen (PSA) metrics. In addition, Russell Z. Szmulewitz, MD, of the University of Chicago School of Medicine, and colleagues concluded that the pharmacoeconomic implications of this study’s findings were compelling, and their data “warrant consideration by prescribers, payers, and patients.”
In the analysis of this prospective international randomized phase II study, published in the Journal of Clinical Oncology, the authors noted that abiraterone has an approximate retail cost of $10,000 per month. With a median time receiving treatment of 16.5 months in metastatic castration-resistant prostate cancer, the per-patient cost savings with the low dosing of abiraterone would exceed $100,000. In addition, the authors commented, abiraterone was recently shown to improve survival in the metastatic castration-sensitive prostate cancer setting, with median progression-free survival estimates of 33 to 44 months, potentially resulting in per-patient cost savings of more than $300,000.
Of 72 total patients, 36 patients each were accrued to the low-dose and standard-dose cohorts. At 12 weeks, there was a greater effect on PSA level in the low-dose arm (mean log change, –1.59) than in the standard-dose arm (mean log change, –1.19). The PSA response rate was 58% in the low-dose cohort and 50% in the standard-dose cohort; the median progression-free survival was approximately 9 months in both groups.
“Given the prevalent paradigm of developing drugs with large food effects under fasting conditions, there are multiple other opportunities to lower drug costs by administration with food,” Dr. Szmulewitz and colleagues stated.