Antitumour activity of abiraterone acetate against metastatic castration-resistant prostate cancer progressing after docetaxel and enzalutamide (MDV3100).

Androgen receptor (AR) signalling remains critically important in metastatic castration-resistant prostate cancer (mCRPC) as confirmed by recent phase III trials, showing a survival advantage for abiraterone acetate and enzalutamide (MDV3100). The antitumour activity of abiraterone and prednisolone in patients pre-treated with enzalutamide is as yet unknown.

We investigated the antitumour activity of abiraterone and prednisolone in patients with mCRPC who had progressed following treatment with docetaxel (Taxotere) and enzalutamide. Clinical data were retrospectively analysed for prostate-specific antigen (PSA) and RECIST responses, clinical benefit and survival.

Thirty-eight patients were included in the analysis. The median age was 71 years (range 52-84); metastatic sites included bone disease in 37 patients (97%), lymph nodes in 15 patients (39%) and visceral disease in 10 patients (26%). Abiraterone was well tolerated. Three patients (8%) attained a PSA response, defined as ≥50% decline in PSA confirmed after ≥4 weeks, while seven patients (18%) had a ≥30% PSA decline. The median progression-free survival (PFS) was 2.7 months (95% CI 2.3-4.1). Of the 12 patients assessable radiologically, only 1 (8%) attained a confirmed partial response.

Abiraterone and prednisolone have modest antitumour activities in patients with mCRPC pretreated with docetaxel and enzalutamide.

Annals of oncology : official journal of the European Society for Medical Oncology. 2019 Dec 04 [Epub]

Y Loriot, D Bianchini, E Ileana, S Sandhu, A Patrikidou, C Pezaro, L Albiges, G Attard, K Fizazi, J S De Bono, C Massard

Department of Cancer Medicine, Institut Gustave Roussy, University of Paris-Sud, INSERM 981, Villejuif, France. Electronic address: ., Section of Medicine, The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Sutton, UK., Department of Cancer Medicine, Institut Gustave Roussy, University of Paris-Sud, INSERM 981, Villejuif, France.