BACKGROUND: The open-label, single-arm enzalutamide expanded access program (EAP) in the United States and Canada evaluated the safety of enzalutamide in patients with metastatic castration-resistant prostate cancer (mCRPC) who had previously received docetaxel.
METHODS: Patients (n = 507) received enzalutamide 160 mg/day until disease progression, intolerable adverse events (AEs), or commercial availability occurred. AEs and other safety variables were assessed on day 1, weeks 4 and 12, and every 12 weeks thereafter. Data following transition to commercial drug were not collected.
RESULTS: Median age was 71 years (range 43-97); 426 patients (83.9%) had a baseline ECOG score of ≤ 1. In addition to docetaxel, the majority of patients had received prior prostate cancer treatments such as abiraterone (76.1%) or cabazitaxel (28.6%). Median study treatment duration was 2.6 months (range 0.03-9.07). The most frequently reported reasons for discontinuation were commercial availability of enzalutamide (46.7%) and progressive disease (33.7%). A total of 88.2% of patients experienced AEs; 45.4% experienced AEs with a maximum grade of 1 or 2. Fatigue (39.1%), nausea (22.7%), and anorexia (14.8%) were the most commonly reported AEs. Seizure was reported in four patients (0.8%). The most commonly reported event leading to death was progression of metastatic prostate cancer (7.7%).
CONCLUSION: In this heavily pretreated EAP population with progressive mCRPC, enzalutamide was well tolerated and the safety profile was consistent with that of the AFFIRM trial.
Written by:
Joshua AM, Shore ND, Saad F, Chi KN, Olsson CA, Emmenegger U, Scholz M, Berry W, Mukherjee SD, Winquist E, Haas NB, Foley MA, Dmuchowski C, Perabo F, Hirmand M, Hasabou N, Rathkopf D. Are you the author?
University Health Network/Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
Reference: Prostate. 2015 Feb 14. Epub ahead of print.
doi: 10.1002/pros.22965
PubMed Abstract
PMID: 25683285