MAINTENANCE OF ABIRATERONE BENEFIT FOR PATIENTS WITH VISCERAL METASTASES

Prostate Cancer Prostatic Dis. 2013 Oct 1. doi: 10.1038/pcan.2013.41. [Epub ahead of print]

Exploratory analysis of the visceral disease subgroup in a phase III study of abiraterone acetate in metastatic castration-resistant prostate cancer.

Goodman OB Jr, Flaig TW, Molina A, Mulders PF, Fizazi K, Suttmann H, Li J, Kheoh T, de Bono JS, Scher HI.

Source

Department of Medical Oncology, Comprehensive Cancer Centers of Nevada, Las Vegas, NV, USA.

Abstract

Background:Visceral disease, non-nodal soft-tissue metastases predominantly involving the lung and liver, is a negative prognostic factor in patients with metastatic castration-resistant prostate cancer (mCRPC). An exploratory analysis of COU-AA-301 assessed whether abiraterone acetate (AA) improved overall survival (OS) in mCRPC patients with visceral disease progressing post docetaxel.Methods:In COU-AA-301, post-docetaxel mCRPC patients were randomized 2:1 to AA 1000 mg (n=797) or placebo (n=398) once daily, each with prednisone 5 mg b.i.d. The primary end point was OS; secondary end points included radiographic progression-free survival (rPFS), PSA response rate and objective response rate (ORR). Treatment effects in visceral disease (n=352) and non-visceral disease (n=843) subsets were examined using final data (775 OS events).Results:AA plus prednisone produced similar absolute improvement in median OS in patients with (4.6 months) and without (4.8 months) visceral disease versus prednisone; hazard ratios (HRs) were 0.79 (95% confidence interval (CI): 0.60-1.05; P=0.102) and 0.69 (95% CI: 0.58-0.83; P<0 .0001="" 0.46-0.78="" 0.58-0.80="" 0.60="" 0.68="" 0="" 11="" 19="" 1="" 2013="" 28="" 30="" 3="" 5="" 7="" aa="" abiraterone.prostate="" advance="" adverse="" and="" arms="" baseline="" benefit="" between="" blockade="" both="" cancer="" ci:="" clinical="" comparably="" cyp17="" disease.="" disease.conclusions:aa="" disease="" does="" doi:10.1038="" each="" end="" endpoint="" events="" for="" from="" grade="" hrs="" improved="" improvements="" in="" incidence="" including="" increased="" mcrpc="" non-visceral="" not="" october="" of="" online="" or="" orrs="" os="" outcomes="" p="" patients="" pcan.2013.41.="" plus="" points="" post-docetaxel="" preclude="" prednisone="" presence="" prostatic="" provides="" psa="" publication="" rates="" related="" respectively.="" response="" rpfs="" secondary="" significant="" significantly="" similar="" subset.="" subsets:="" subsets="" the="" to="" treatment="" versus="" visceral="" was="" were="" with="" without="">