This study is a randomised, open-label, multicentre phase III clinical study evaluating the efficacy and safety of JS105 combined with Dalpiciclib and Fulvestrant compared with Dalpiciclib and Fulvestrant in patients with PIK3CA-mutated, HR-positive, HER2-negative recurrent or metastatic breast cancer.
At the time of signing the consent form, age must be between 18 and 75 years old, males and females;
Patients with unresectable PIK3CA-mutated HR-positive HER2-negative recurrent or metastatic breast cancer;
Consent to provide tumour tissue or blood samples to determine the PIK3CA mutation status;
ECOG 0 or 1;
Previously treated with fulvestrant or PI3K/AKT/mTOR inhibitors;
Presence of untreated or active central nervous system (CNS) metastases;
Presence of significant clinical symptoms or uncontrolled pleural effusion, ascites, or pericardial effusion that require repeated drainage (once a month or more frequently);
Untreated spinal cord compression, or previously treated spinal cord compression without clinical evidence of disease stability for at least 4 weeks prior to the first study treatment;