NCT03332797

A Study of GDC-9545 Alone or in Combination With Palbociclib and/or Luteinizing Hormone-Releasing Hormone (LHRH) Agonist in Locally Advanced or Metastatic Estrogen Receptor-Positive Breast Cancer

A Phase Ia/Ib, Multicenter, Open-Label, Dose Escalation, Dose Expansion Study Evaluating the Safety, Pharmacokinetics, and Activity of GDC-9545 Alone or in Combination With Palbociclib and/or LHRH Agonist in Patients With Locally Advanced or Metastatic Estrogen Receptor-Positive Breast Cancer

• Status: Active Not Recruiting
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 181 (actual)
• Sponsor: Genentech, Inc. · Industry
• Sex: Female
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This study will evaluate the safety, pharmacokinetic (PK), pharmacodynamic (PD) activity, and preliminary anti-tumor activity of GDC-9545 as a single agent and in combination with palbociclib and/or luteinizing hormone-releasing hormone (LHRH) agonist in participants with advanced or metastatic estrogen receptor (ER)-positive (human epidermal growth factor receptor 2 \[HER2\]-negative) breast cancer.

Conditions

• Breast Cancer

Interventions

Type	Name	Description
DRUG	GDC-9545	GDC-9545 will be administered orally, once daily, on Days 1-28 of each 28-day cycle, until disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
DRUG	Palbociclib	Palbociclib will be administered orally, once daily, at the label-recommended dose of 125 mg on Days 1-21 of each 28-day cycle, until disease progression, unacceptable toxicity, withdrawal of consent, or study termination.
DRUG	LHRH Agonist	The LHRH agonist (leuprolide acetate, goserelin acetate, or triptorelin pamoate) will be administered by injection once every 4 weeks on Day 1 of each 28-day cycle, according to the label. The investigator will choose the appropriate LHRH agonist approved for use in breast cancer.

Timeline

• Start date: 2017-11-24
• Primary completion: 2026-07-31
• Completion: 2026-07-31
• First posted: 2017-11-06
• Last updated: 2026-02-13

Locations

23 sites across 5 countries: United States, Australia, South Korea, Spain, United Kingdom

Regulatory

• FDA-regulated drug study