It may be possible to take one-fourth of a dose of abiraterone acetate (ZYTIGA), with a low fat meal and get the same benefits as taking the standard dose as recommended on an empty stomach. New data from a small multicenter, randomized, phase II clinical trial presented at the 2017 Genitourinary Cancers Symposium in Orlando, Florida, demonstrated that the 36 patients who took 250 milligrams of the drug with a low-fat breakfast had outcomes that were virtually identical to the 36 patients who took the standard dose (1000 milligrams) on an empty stomach.1
The finding has significant financial implications. The drug now retails for more than $9,000 per month. Patients taking abiraterone acetate typically stay on the medication for 12 to 18 months.
The study was conducted in the United States and Singapore and included 72 patients aged 52 to 89 years (median 74) with advanced prostate cancer whose disease had progressed despite standard initial hormonal therapy. The men were randomly assigned to take the standard dose on an empty stomach or the low dose with breakfast.
The primary objective of the study was to compare the change in blood levels of prostate specific antigen (PSA). Despite a 75% difference in dose, there was no difference in abiraterone activity as measured by variation in PSA levels between the 2 groups of patients. The time to disease progression also was nearly identical for both arms of the study (about 14 months). Patients who took the drug with food appeared to have an additional benefit. They were less likely to complain about stomach discomfort than those who took the drug as recommended.
1. Szmulewitz RZ, Ibraheem AF, Peer CJ, et al. A prospective international randomized phase II study evaluating the food effect on the pharmacokinetics (PK) and pharmacodynamics (PD) of abiraterone acetate (AA) in men with castration-resistant prostate cancer (CRPC). J Clin Oncol. 2017, 35 (suppl 6S; abstract 176).