Pharmacokinetic Aspects of the Two Novel Oral Drugs Used for Metastatic Castration-Resistant Prostate Cancer: Abiraterone Acetate and Enzalutamide

Clin Pharmacokinet. 2016 Nov;55(11):1369-1380. doi: 10.1007/s40262-016-0403-6.

Abstract

Two novel oral drugs that target androgen signaling have recently become available for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Abiraterone acetate inhibits the synthesis of the natural ligands of the androgen receptor, whereas enzalutamide directly inhibits the androgen receptor by several mechanisms. Abiraterone acetate and enzalutamide appear to be equally effective for patients with mCRPC pre- and postchemotherapy. Rational decision making for either one of these drugs is therefore potentially driven by individual patient characteristics. In this review, an overview of the pharmacokinetic characteristics is given for both drugs and potential and proven drug-drug interactions are presented. Additionally, the effect of patient-related factors on drug disposition are summarized and the limited data on the exposure-response relationships are described. The most important pharmacological feature of enzalutamide that needs to be recognized is its capacity to induce several key enzymes in drug metabolism. The potency to cause drug-drug interactions needs to be addressed in patients who are treated with multiple drugs simultaneously. Abiraterone has a much smaller drug-drug interaction potential; however, it is poorly absorbed, which is affected by food intake, and a large interpatient variability in drug exposure is observed. Dose reductions of abiraterone or, alternatively, the selection of enzalutamide, should be considered in patients with hepatic dysfunction. Understanding the pharmacological characteristics and challenges of both drugs could facilitate decision making for either one of the drugs.

Publication types

  • Review

MeSH terms

  • Abiraterone Acetate / pharmacokinetics*
  • Abiraterone Acetate / therapeutic use
  • Antineoplastic Agents / pharmacokinetics*
  • Antineoplastic Agents / therapeutic use
  • Area Under Curve
  • Cytochrome P-450 Enzyme System / drug effects
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Enzyme Induction / drug effects
  • Fasting
  • Half-Life
  • Humans
  • Liver Failure / metabolism
  • Male
  • Metabolic Clearance Rate
  • Phenylthiohydantoin / analogs & derivatives*
  • Phenylthiohydantoin / pharmacokinetics
  • Phenylthiohydantoin / therapeutic use
  • Prostatic Neoplasms, Castration-Resistant / drug therapy*
  • Receptors, Androgen / drug effects

Substances

  • Antineoplastic Agents
  • MDV 3100
  • Receptors, Androgen
  • Phenylthiohydantoin
  • Cytochrome P-450 Enzyme System
  • Abiraterone Acetate