This clinical trial is focused on studying a type of breast cancer known as ER-positive/HER2-negative early breast cancer. This type of cancer is characterized by the presence of estrogen receptors (ER) and the absence of human epidermal growth factor receptor 2 (HER2) in the cancer cells. The study involves two treatments: Giredestrant, also known by its code name GDC-9545, and Tamoxifen. Giredestrant is a new type of medication that works by degrading estrogen receptors, while Tamoxifen is a well-known treatment that blocks estrogen receptors.
The purpose of the study is to observe changes in the growth of cancer cells by measuring a protein called Ki67, which is associated with cell proliferation. Participants in the study will receive either Giredestrant or Tamoxifen. The study will involve taking a sample of the tumor before and after the treatment to assess the effect of the medication on the cancer cells. This will help researchers understand how these treatments affect the growth of cancer cells in patients with this specific type of breast cancer.
Participants will be monitored throughout the study to track any changes in their condition and to identify any side effects of the treatments. The study aims to provide valuable information on the effectiveness of Giredestrant compared to Tamoxifen in treating ER-positive/HER2-negative early breast cancer. This research could potentially lead to improved treatment options for patients with this type of breast cancer.



France
Spain