Sequencing of Cabazitaxel and Abiraterone Acetate After Docetaxel in Metastatic Castration-Resistant Prostate Cancer: Treatment Patterns and Clinical Outcomes in Multicenter Community-Based US Oncology Practices

Clin Genitourin Cancer. 2015 Aug;13(4):309-318. doi: 10.1016/j.clgc.2014.12.019. Epub 2015 Jan 9.

Abstract

Background: Optimal sequencing of cabazitaxel (C) and abiraterone acetate (A) after docetaxel (D) for metastatic castration-resistant prostate cancer (mCRPC) is unclear. We assessed treatment patterns and outcomes in patients with mCRPC receiving different sequences of A or C, or both, after administration of D.

Methods: Retrospective analysis was conducted of US Oncology Network iKnowMed (iKM) electronic health record (EHR) data to assess patients with mCRPC who received treatment with D and were subsequently treated with C or A, or both, between April 2011 and May 2012. Patients received 2 or 3 drugs: DA, DC, DAC, or DCA. Overall survival (OS) and time to treatment failure (TTF) were analyzed by the Kaplan-Meier method from the start to the end of second-line therapy after administration of D (TTF1) and to the end of combined second- and third-line therapy (TTF2) for 3-drug sequences. Multivariable Cox proportional hazard models evaluated the impact of baseline clinical prognostic factors and treatment sequence on OS and TTF.

Results: Of 350 patients who were treated with D and subsequent therapies, 183 (52.3%) received DA, 54 (15.4%) received DC, 77 (22.0%) received DCA, and 36 (10.3%) received DAC. In a multivariable analysis, adjusted comparisons suggested that 3-drug sequences were associated with improved OS versus 2-drug sequences (hazard ratio [HR], 0.21; 95% confidence interval [CI], 0.092-0.476; P = .0002). There were no statistically significant differences in OS and TTF for DC versus DA, and OS was significantly greater for DCA versus DAC (HR, 0.13; 95% CI, 0.022-0.733; P = .0210). More cycles of C were administered in DCA than in DAC (median 6 vs. 4; t test P < .0001), whereas the duration of A treatment was similar.

Conclusion: Administration of 3 agents in the DCA sequence was more optimal for treating mCRPC in this hypothesis-generating study.

Keywords: Clinical outcomes; Electronic health record; Retrospective; Treatment sequence; mCRPC.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abiraterone Acetate / administration & dosage
  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Bone Neoplasms / drug therapy*
  • Bone Neoplasms / mortality
  • Bone Neoplasms / secondary
  • Disease-Free Survival
  • Docetaxel
  • Drug Administration Schedule
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Prostatic Neoplasms, Castration-Resistant / drug therapy*
  • Prostatic Neoplasms, Castration-Resistant / mortality
  • Prostatic Neoplasms, Castration-Resistant / pathology
  • Retrospective Studies
  • Taxoids / administration & dosage
  • Treatment Outcome

Substances

  • Taxoids
  • Docetaxel
  • cabazitaxel
  • Abiraterone Acetate