781P - Analysis of European Patients Enrolled in a Global Early Access Protocol with Abiraterone Acetate for Metastatic Castration-Resistant Prostate Cancer Progressing After Chemotherapy

Abstract

ABSTRACT Aim: Following release of COU-AA-301 pivotal trial data, a global early access protocol (EAP) was opened to enable preapproval access to abiraterone acetate (AA) for metastatic castration-resistant prostate cancer (mCRPC) patients (pts) who had progressed after 1 or 2 chemotherapy regimens, 1 of which contained a taxane, and for whom no approved alternative treatment was available. In COU-AA-301, AA + prednisone (P) significantly prolonged median overall survival by 4.6 months in post-docetaxel mCRPC pts, with a 26% reduction (hazard ratio = 0.74 [95% confidence interval (CI), 0.64-0.86]; p Methods: Globally, 2314 mCRPC pts were enrolled and 98.5% of pts had previously received docetaxel. Of those enrolled, 1171 (51%) were European. Pts received AA (1000 mg/d PO) + P (5 mg bid) and continued on the EAP until disease progression, or until AA became available and reimbursed in the respective country. The primary end point was the number of clinically important adverse events (AEs), including ≥ Grade 3 or serious AEs (NCI-CTCAE v 4.0) occurring during treatment and within 30 days of treatment discontinuation. Time to prostate-specific antigen progression (TTPP) and time to clinical progression (TTCP) were used to guide treatment decisions. Results: The median age of European pts was 71 years. 90% and 39% of pts had bone and soft-tissue metastases, respectively. Median duration of therapy was 6.4 months. Median TTPP (385 events) was 9.3 months (95% CI, 8.5-11) and median TTCP (412 events) was 13 months (95% CI, 12-14.8). Grade 3/4 AEs of special interest were hepatotoxicity (6.7%), hypertension (5.1%), cardiac disorders (1.5%), osteoporosis (1.1%), fluid retention/edema (0.9%), and hypokalemia (0.8%). Study discontinuations due to AEs or death were ≤ 8% each. Conclusions: These final analysis results reveal that AA + P is safe and effective across geographically diverse European investigational sites. This EAP enables an early insight into real-world clinical practice in a clinical trial framework. Disclosure: S. Bracarda: has served as an advisory board member for Jannsen, Astellas, Bayer, and Genentech; O. Capoun: has received travel and congress fee support from Janssen, Ipsen, and Astellas; G. Bodoky: has served as an advisory board member for Pfizer, Novartis, Roche, Amgen, Janssen, Lilly, and GSK. I. Skoneczna: has received speaker fees from Janssen. A. Londhe, P. De Porre, D. Atlan, B. Goon, E. Lee, T. McGowan and A. Molina: is an employee of Janssen and holds stock in Johnson & Johnson; V. Naini: is an employee of Janssen; C.N. Sternberg: has received honoraria from Astellas, Johnson & Johnson, Ipsen, Bayer, and Millennium. All other authors have declared no conflicts of interest.