Zytiga approved for use before chemotherapy

on the 1 March 2013

The licence for Zytiga (abiraterone) has been extended to include patients with metastatic castration-resistant prostate cancer who are asymptomatic or mildly symptomatic for whom chemotherapy is not yet indicated.

Abiraterone inhibits the synthesis of androgens in testicular, adrenal and prostatic tumour tissues | SCIENCE PHOTO LIBRARY

Zytiga is used in the same licensed dosage regimen as in patients whose cancer has progressed following or during chemotherapy: 1g (four tablets) once daily at least one hour before or two hours after food, in combination with prednisolone.

The safety and efficacy of abiraterone in chemotherapy-naïve patients (n=1,088) was established in a randomised, placebo-controlled phase III study (COU-AA-302) using the co-primary endpoints of radiographic progression-free survival (PFS) and overall survival. Patients were either using an LHRH analogue or had previously undergone orchidectomy.

Progression-free survival doubled

The study was unblinded when 43% of the expected deaths had occurred following a preplanned interim analysis. The median radiographic PFS was doubled in patients receiving abiraterone compared with placebo: 16.5 months vs 8.3 months (HR 0.53, 95% CI 0.45–0.62, p<0.001). Abiraterone also improved overall survival but did not cross the efficacy boundary.

Serious mineralocorticoid-related adverse events and liver-function abnormalities were more common in the abiraterone arm.

View Zytiga drug record

Further information: Janssen-Cilag Ltd

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