Pharmacokinetic Effects and Safety of Olaparib Administered with Endocrine Therapy: A Phase I Study in Patients with Advanced Solid Tumours

Ruth Plummer, Henk M Verheul, Filip Y F L De Vos, Karin Leunen, L Rhoda Molife, Christian Rolfo, Peter Grundtvig-Sørensen, Jacques De Grève, Sylvie Rottey, Guy Jerusalem, Antoine Italiano, James Spicer, Luc Dirix, Carsten Goessl, Joseph Birkett, Stuart Spencer, Maria Learoyd, Christopher Bailey, Emma Dean

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

INTRODUCTION: The PARP inhibitor olaparib is efficacious as monotherapy and has potential application in combination with endocrine therapy for the treatment of breast cancer. This phase I study assessed the safety and pharmacokinetic (PK) profiles of olaparib combined with tamoxifen, anastrozole or letrozole in patients with advanced solid tumours.

METHODS: During part A, PK profiles were assessed in three consecutive treatment periods: (1) olaparib (tablet) 300 mg bid, days 1-5 followed by a 4-day washout; (2) cohort 1, tamoxifen 60 mg loading dose qd days 10-13, 20 mg qd days 14-26; cohort 2, anastrozole 1 mg qd days 10-19; cohort 3, letrozole 2.5 mg qd days 10-38; (3) as for period 2, with concomitant olaparib 300 mg bid for 5 days. Patients could then enter part B and receive olaparib monotherapy (300 mg bid continuously). Safety was assessed in parts A and B until 12 months after the last patient entered part B.

RESULTS: Seventy-nine patients (20.3% with breast cancer) received treatment in part A; 72 completed part A and 69 entered part B. Anastrozole and letrozole had no effect on the PK profile of olaparib and vice versa. Co-administration with tamoxifen produced a modest decrease in exposure to olaparib [geometric least-squares mean (GLSmean) Cmax,ss and AUC0-τ decreased by 20% (90% CI 0.71-0.90) and 27% (0.63-0.84), respectively]. Exposure to tamoxifen was slightly increased when combined with olaparib [GLSmean Cmax,ss and AUC0-τ increased by 13% (1.06-1.22) and 16% (1.11-1.21), respectively]; however, the 90% CI fell within the 0.7-1.43 boundary and there were no changes in exposure to tamoxifen metabolites. The safety profile for olaparib alone and in combination with the antihormonal therapies was acceptable.

CONCLUSIONS: The combination of olaparib and either anastrozole, letrozole or tamoxifen was generally well tolerated, with no clinically relevant PK interactions identified.

FUNDING: AstraZeneca.

CLINICAL TRIAL REGISTRATION: NCT02093351.

Original languageEnglish
Pages (from-to)1945-1964
Number of pages20
JournalAdvances in Therapy
Volume35
Issue number11
Early online date2018
DOIs
Publication statusPublished - Nov 2018

Keywords

  • Journal Article
  • Anastrozole
  • PARP inhibitor
  • Endocrine therapy
  • Olaparib
  • Safety
  • Pharmacokinetics
  • Tamoxifen
  • Antihormonal therapy
  • Letrozole
  • Lynparza
  • Antineoplastic Agents, Hormonal/administration & dosage
  • Letrozole/administration & dosage
  • Humans
  • Middle Aged
  • Male
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Adult
  • Female
  • Breast Neoplasms/drug therapy
  • Piperazines/administration & dosage
  • Phthalazines/administration & dosage
  • Drug Therapy, Combination/adverse effects
  • Treatment Outcome
  • Tamoxifen/administration & dosage
  • Anastrozole/administration & dosage
  • Poly(ADP-ribose) Polymerase Inhibitors/administration & dosage
  • Drug Monitoring/methods
  • Neoplasms/classification
  • Aged
  • Neoplasm Staging

Fingerprint

Dive into the research topics of 'Pharmacokinetic Effects and Safety of Olaparib Administered with Endocrine Therapy: A Phase I Study in Patients with Advanced Solid Tumours'. Together they form a unique fingerprint.

Cite this