BGB-21447 + fulvestrant

BGB-21447 + fulvestrant is an investigational combination therapy comprising **BGB-21447**, a next-generation, orally bioavailable small molecule inhibitor of the anti-apoptotic protein B-cell leukemia/lymphoma 2 (BCL2), and **fulvestrant**, a selective estrogen receptor degrader (SERD). This combination is in Phase 1 clinical trials for adults with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer who have received at least two prior lines of therapy, including endocrine therapy and a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor. BGB-21447 directly targets BCL2, which promotes tumor cell survival, while fulvestrant reduces estrogen signaling by targeting and degrading the estrogen receptor[1][3][4][5].