The effect of prior androgen synthesis inhibition on outcomes of subsequent therapy with docetaxel in patients with metastatic castrate-resistant prostate cancer: results from a retrospective analysis of a randomized phase 3 clinical trial (CALGB 90401) (Alliance)

Cancer. 2013 Oct 15;119(20):3636-43. doi: 10.1002/cncr.28285. Epub 2013 Jul 31.

Abstract

Background: Preliminary data suggest a potential decreased benefit of docetaxel in patients with metastatic, castration-resistant prostate cancer (mCRPC) who previously received abiraterone acetate, a novel androgen synthesis inhibitor (ASI). Cancer and Leukemia Group B (CALGB) trial 90401 (Alliance), a phase 3 trial in patients with mCRPC who received docetaxel-based chemotherapy, offered the opportunity to evaluate effect of prior ketoconazole, an earlier generation ASI, on clinical outcomes after docetaxel.

Methods: In CALGB trial 90401, 1050 men with chemotherapy-naive mCRPC were randomized to receive treatment with docetaxel and prednisone that included either bevacizumab or placebo. In total, 1005 men (96%) had data available regarding prior ketoconazole therapy. The observed effects of prior ketoconazole on overall survival (OS), progression-free survival (PFS), prostate-specific antigen (PSA) decline, and the objective response rate (ORR) were assessed using proportional hazards and Poisson regression methods adjusted for validated prognostic factors and treatment arm.

Results: Baseline characteristics between patients who did (N=277) and did not (N=728) receive prior ketoconazole therapy were similar. There were no statistically significant differences between patients who did and those who did not receive prior ketoconazole therapy with respect to OS (median OS, 21.1 months vs 22.3 months, respectively; stratified log-rank P=.635), PFS (median PFS, 8.1 months vs 8.6 months, respectively; stratified log-rank P=.342), the proportion achieving a decline ≥ 50% in PSA (61% vs 66%, respectively; relative risk, 1.09; adjusted P=.129), or ORR (39% vs 43%, respectively; relative risk, 1.11; adjusted P=.366).

Conclusions: As measured by OS, PFS, PSA, and the ORR, there was no evidence that prior treatment with ketoconazole had an impact on the clinical outcomes of patients with mCRPC who received subsequent docetaxel-based therapy. The current results highlight the need for prospective studies to assess for potential cross-resistance with novel ASIs and to define the optimal sequence of therapy in mCRPC.

Keywords: androgen antagonists; chemotherapy; ketoconazole; prostatic neoplasms; steroid 17-alpha-hydroxylase.

Publication types

  • Clinical Trial, Phase III
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Androgen Antagonists / pharmacology*
  • Antibodies, Monoclonal, Humanized / administration & dosage
  • Antifungal Agents / pharmacology
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Bevacizumab
  • Bone Neoplasms / drug therapy*
  • Bone Neoplasms / mortality
  • Bone Neoplasms / secondary
  • Chemotherapy, Adjuvant
  • Disease Progression
  • Docetaxel
  • Drug Therapy, Combination
  • Follow-Up Studies
  • Humans
  • International Agencies
  • Ketoconazole / pharmacology
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / mortality
  • Liver Neoplasms / secondary
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / mortality
  • Lung Neoplasms / secondary
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Orchiectomy
  • Prednisone / pharmacology
  • Prognosis
  • Prostatic Neoplasms / drug therapy*
  • Prostatic Neoplasms / mortality
  • Prostatic Neoplasms / pathology
  • Retrospective Studies
  • Survival Rate
  • Taxoids / administration & dosage

Substances

  • Androgen Antagonists
  • Antibodies, Monoclonal, Humanized
  • Antifungal Agents
  • Taxoids
  • Docetaxel
  • Bevacizumab
  • Ketoconazole
  • Prednisone

Grant support