Another Trial Supports Low-Dose Abiraterone Acetate in mCRPC

This study, published in JCO Global Oncologyand focused on abiraterone acetate (AA), a drug used to treat metastatic castration-resistant prostate cancer, suggests that a smaller dose of AA is as effective as the standard dose (we already talked about another study pointing in the same direction in Singapore, but this sample is bigger). The study was carried out in Brazil.

Typically, patients take 1,000 milligrams of the drug on an empty stomach, a regimen that’s effective but expensive, especially in Brazil, where 80% of patients rely on a public healthcare system that doesn’t cover it.
Researchers tested a 250-milligram dose taken with a low-fat meal, slashing the amount of drug needed by 75%. The trick lies in the food, which boosts the drug’s absorption, allowing a smaller dose to pack the same punch.
Over two years, the team tracked 96 patients, most with incomes below Brazil’s average, who received the low-dose treatment alongside a small dose of prednisone. The results were striking: 60.2% of patients saw their prostate-specific antigen (PSA) levels drop by at least half after 12 weeks. For those in earlier stages of treatment, the response rate hit 68.3%. Patients went an average of 7.9 months before their disease progressed, and overall survival reached 20.6 months. Those who responded well to the drug lived nearly 29 months, compared to just over 12 months for those who didn’t.

These numbers stack up well against major international trials of the standard 1,000-milligram dose, which reported PSA response rates from 29.5% to 62% and survival times from 14.8 to 34.7 months. The low-dose approach also proved gentler, with no severe side effects reported. Common issues like high blood pressure (22.2%), fatigue (19.4%), and low potassium (13.9%) were manageable, and only one patient stopped treatment due to a side effect. Led by Dr. Julia Belone Lopes, the study builds on earlier research showing that food can enhance abiraterone’s effectiveness, allowing lower doses to achieve similar results.

The reduced dose cuts costs dramatically, making it feasible for public hospitals to offer the drug. Taking it with a simple meal like rice and beans also simplifies the process, helping patients stick to the regimen compared to the fasting required for the standard dose.The study isn’t without flaws. Conducted at a single hospital, it needs broader testing to confirm results across diverse settings. Researchers also didn’t measure drug levels in the blood, relying instead on prior studies to support the food effect. Larger trials are already in the works, and if they confirm these results, low-dose abiraterone could soon become a standard option worldwide.

Source.