XZP-3287 + letrozole

XZP-3287 + letrozole is a **combination drug** consisting of XZP-3287 (also known as bireociclib), a small molecule cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, and letrozole, an aromatase inhibitor. This combination is under clinical investigation for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer. Bireociclib (XZP-3287) blocks cell cycle progression by selectively inhibiting CDK4/6, leading to suppression of cancer cell proliferation. Letrozole inhibits the conversion of androgens to estrogens, reducing estrogen-mediated stimulation of breast cancer cells. The combination aims to enhance endocrine therapy efficacy by simultaneously arresting cell cycle progression and limiting hormonal growth signals. Both agents have complementary but distinct mechanisms of action. XZP-3287 was developed by Xuanzhu Biopharmaceutical and has received marketing authorization in China for HR+/HER2- advanced breast cancer when combined with fulvestrant, and is in phase III trial when combined with letrozole[1][3][4][7][9].

Other names

bireociclib + letrozole