BG-68501 + fulvestrant

BG-68501 + fulvestrant is a combination therapy under clinical investigation for advanced, nonresectable, or metastatic solid tumors, with a primary focus on hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) breast cancer. BG-68501 (also known as ETX-197) is a highly selective, oral cyclin-dependent kinase 2 (CDK2) inhibitor (~100x selective vs other CDKs) designed to target tumors with resistance to CDK4/6 inhibitors and/or high cyclin E1 activity. Fulvestrant is a selective estrogen receptor degrader (SERD) acting as a pure estrogen receptor antagonist, commonly used in the treatment of HR+ breast cancer. The combination is being tested for enhanced antitumor activity in cancers that have progressed after endocrine therapy, especially following CDK4/6 inhibitor resistance. Early clinical data support manageable safety, with observed responses in heavily pretreated patients[1][2][5][6][7].