A Study Evaluating the Efficacy and Safety of GDC-9545 Combined With Palbociclib Compared With Letrozole Combined With Palbociclib in Participants With Estrogen Receptor-Positive, HER2-Negative Locally Advanced or Metastatic Breast Cancer

Official Title

A Phase III Randomized, Double-Blind, Placebo-Controlled, Multicentre Study Evaluating the Efficacy and Safety of GDC-9545 Combined With Palbociclib Compared With Letrozole Combined With Palbociclib in Patients With Estrogen Receptor-Positive, HER2-Negative Locally Advanced or Metastatic Breast Cancer

Summary:

This Phase III, randomized, double-blind, placebo-controlled, multicentre study will evaluate the efficacy and safety of GDC-9545 combined with palbociclib compared with letrozole combined with palbociclib in patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor-2 (HER2)-negative locally advanced (recurrent or progressed) or metastatic breast cancer.

Trial Description

Primary Outcome:

  • Progression-Free Survival (PFS), as Determined by the Investigator According to RECIST v1.1
Secondary Outcome:
  • Overall Survival
  • Objective Response Rate, as Determined by the Investigator According to RECIST v1.1
  • Duration of Response, as Determined by the Investigator According to RECIST v1.1
  • Clinical Benefit Rate, as Determined by the Investigator According to RECIST v1.1
  • Time to Deterioration in Pain Level, Defined as the Time to First Documented ≥2-Point Increase from Baseline in the 'Worst Pain' Item from the Brief Pain Inventory-Short Form (BPI-SF) Questionnaire
  • Time to Deterioration in Pain Presence and Interference, Defined as the Time to First Documented ≥10-Point Increase from Baseline in the EORTC QLQ-C30 Linearly Transformed Pain Scale Score
  • Time to Deterioration in Physical Functioning, Defined as the Time to First Documented ≥10-Point Decrease from Baseline in the EORTC QLQ-C30 Linearly Transformed Physical Functioning Scale Score
  • Time to Deterioration in Role Functioning, Defined as the Time to First Documented ≥10-Point Decrease from Baseline in the EORTC QLQ-C30 Linearly Transformed Role Functioning Scale Score
  • Time to Deterioration in Global Health Status and Quality of Life (GHS/QoL), Defined as the Time to First Documented ≥10-Point Decrease from Baseline in the EORTC QLQ-C30 Linearly Transformed GHS/QoL Scale Score
  • Number of Participants with Adverse Events, Severity Determined According to National Cancer Institute Common Terminology Criteria for Adverse Events, Version 5.0 (NCI-CTCAE v5.0)
  • Number of Participants with Vital Sign Abnormalities Over the Course of the Study
  • Plasma Concentration of GDC-9545 at Specified Timepoints
  • Plasma Concentration of Palbociclib at Specified Timepoints

View this trial on ClinicalTrials.gov

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Resources

Canadian Cancer Society

These resources are provided in partnership with the Canadian Cancer Society