This clinical trial is focused on studying a type of breast cancer known as advanced breast cancer that has specific characteristics: it is hormone receptor (HR)-positive, HER2-negative, and has a PIK3CA mutation. The study is investigating the effectiveness and safety of combining the medication alpelisib with either fulvestrant or letrozole. These medications are used to treat patients whose cancer has progressed after previous treatments. Alpelisib is taken as a film-coated tablet, while fulvestrant is given as an injection, and letrozole is taken as a tablet.
The purpose of the study is to see how well patients do without their disease getting worse over a period of six months. The study is divided into three groups, or cohorts. Two of these groups will receive alpelisib combined with fulvestrant, and the third group will receive alpelisib combined with letrozole. The study will monitor patients to see how they respond to the treatment and whether the cancer stops growing or spreading. The study will also look at how long patients live and any side effects they might experience.
Participants in the study will receive treatment for up to 93 days. The study will track the progress of the disease and any changes in the patients’ health. The goal is to gather information that could help improve treatment options for people with this type of breast cancer in the future. The study will also include a group of patients who will receive a placebo to compare the effects of the actual medications with no active treatment. This research is important for understanding how these medications can help manage advanced breast cancer with specific genetic mutations.



Denmark
Italy