CI

At a glance

ClinicalIndex Comparison Record
Phase 2Completed· 92 enrolled
Drug / intervention
Giredestrant +1 moredrug
Likely dose
Not stated in record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT05659563
NCT05659563Phase 2Completed

Preoperative Window of Opportunity Study With Giredestrant (GDC-9545) or Tamoxifen in Premenopausal Women With Estrogen Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative & Ki67≥10% Early Breast Cancer

MedSIR·interventional·Posted Dec 21, 2022·Updated Mar 19, 2026

In Brief

A Phase 2 clinical trial evaluating Giredestrant and Tamoxifen for Breast Cancer and Breast Cancer, Early-Onset. Completed, enrolled 92 participants across 18 sites in 2 countries.

Detailed Summary

This study is a window of opportunity clinical trial to evaluate the efficacy of giredestrant (GDC-9545) or tamoxifen in estrogen receptor-positive (ER\[+\])/human epidermal growth factor receptor 2-negative (HER2\[-\]) primary invasive adenocarcinoma of the breast with Ki67 level ≥ 10%. A total of 92 patients will be enrolled in this trial and randomized 1:1 in the arm A with giredestrant (GDC-9545) and the arm B with tamoxifen, with a total duration of treatment of 15 days. This study will analyze the efficacy of giredestrant (GDC-9545) as determined by Ki67 expression between baseline tumor biopsy samples and post-treatment biopsy samples.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesFrance, Spain
Collaborators--

Timeline

Phase 2CompletedFinished
2023202420252026
First PostedDec 21, 2022
Enrollment StartJul 20, 2023
Primary CompletionJan 30, 2025
TodayJul 2, 2026
Enrollment to primary: 1.5 yearsPosted 3.5 years ago

Interventions

Giredestrantdrug

Giredestrant is a highly potent, non-steroidal, oral selective ER antagonist and degrader (SERD)

Tamoxifendrug

Tamoxifen is a selective estrogen receptor (ER) modulator