aromatase inhibitor + pembrolizumab

Aromatase inhibitor + pembrolizumab is an investigational combination therapy consisting of a standard aromatase inhibitor (AI) and the immune checkpoint inhibitor pembrolizumab. Aromatase inhibitors are small molecule drugs that block the enzyme aromatase, thereby reducing estrogen production, which is critical for hormone receptor–positive breast cancer growth. Pembrolizumab is a monoclonal antibody that targets programmed cell death protein 1 (PD-1), blocking its interaction with PD-L1 and PD-L2 to enhance T-cell mediated antitumor immunity. This combination has been studied in patients with hormone receptor–positive, HER2-negative metastatic breast cancer to evaluate safety and efficacy. Clinical trials have shown the regimen to be generally well tolerated but with modest clinical activity comparable to AI monotherapy[1][2][3].