title: Efficacy and Safety of Abiraterone Acetate in Elderly (75 Years or Older) Chemotherapy Naïve Patients with Metastatic Castration Resistant Prostate Cancer.
abstract: OBJECTIVE
  Metastatic castration resistant prostate cancer primarily affects elderly men. In this post hoc analysis we investigated the safety and efficacy of abiraterone acetate in elderly (age 75 years or greater) and younger (less than 75 years) patient subgroups at the prespecified interim analysis (55% of total overall survival events) for the COU-AA-302 (Abiraterone Acetate in Asymptomatic or Mildly Symptomatic Patients with Metastatic Castration-Resistant Prostate Cancer) trial.
  
  
  METHODS
  Patients were stratified and randomized 1:1 to abiraterone acetate 1,000 mg plus prednisone/prednisolone 5 mg twice daily (abiraterone-prednisone) vs placebo plus prednisone/prednisolone 5 mg twice daily (prednisone alone). Co-primary end points were radiographic progression-free and overall survival. Median time to event and HR were estimated using the Kaplan-Meier method and a Cox model, respectively.
  
  
  RESULTS
  A total of 350 elderly patients treated with abiraterone-prednisone had significant improvements in overall and radiographic progression-free survival vs those with prednisone alone (HR 0.71, 95% CI 0.53-0.96 vs HR 0.63, 95% CI 0.48-0.83), similar to 738 younger patients (HR 0.81, 95% CI 0.63-1.03 vs HR 0.49, 95% CI 0.40-0.59). All secondary end points favored the abiraterone-prednisone arm for both age subgroups. Specific adverse events with abiraterone-prednisone were similar between the age subgroups. Elderly patients in both treatment arms had higher rates of fluid retention and cardiac disorders than younger patients, although rates of dose reduction or treatment interruptions due to adverse events were low in both age subgroups.
  
  
  CONCLUSIONS
  Abiraterone acetate demonstrated clinical benefit and was well tolerated in elderly and younger men with chemotherapy naïve, metastatic castration resistant prostate cancer. Thus, findings support it as a treatment option for elderly patients who may not tolerate other therapies with greater toxicity.
authors.affiliation: Department of Genitourinary Oncology, Massachusetts General Hospital Cancer Center, Boston, Massachusetts. Electronic address: smith.matthew@mgh.harvard.edu.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Smith
authors.affiliation: Department of Oncology and Internal Medicine, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Dana E
authors.initials: DE
authors.lastname: Rathkopf
authors.affiliation: Department of Urology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: Peter F A
authors.initials: PF
authors.lastname: Mulders
authors.affiliation: Department of Oncology, Vall d'Hebron University Hospital, Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Carles
authors.affiliation: Department of Urology, University Hospitals of KU Leuven, Leuven, Belgium.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Van Poppel
authors.affiliation: Department of Biostatistics Oncology, Janssen Research & Development, Raritan, New Jersey.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Biostatistics and Programming, Janssen Research & Development, San Diego, California.
authors.forename: Thian
authors.initials: T
authors.lastname: Kheoh
authors.affiliation: Department of WC Clinical Oncology, Janssen Research & Development, Los Angeles, California.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Griffin
authors.affiliation: Department of Oncology, Janssen Research & Development, Los Angeles, California.
authors.forename: Arturo
authors.initials: A
authors.lastname: Molina
authors.affiliation: Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Ryan
mesh_terms: D000069501:Abiraterone Acetate / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage; D018450:Disease Progression; D018572:Disease-Free Survival; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011241:Prednisone / Q000008:administration & dosage*; D064129:Prostatic Neoplasms, Castration-Resistant / Q000175:diagnosis / Q000188:drug therapy* / Q000556:secondary; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D005938:Glucocorticoids; D000069501:Abiraterone Acetate; D011241:Prednisone
keywords: 17-(3-pyridyl)-5,16-androstadien-3beta-acetate; aged; drug tolerance; prostatic neoplasms; treatment outcome