||Verzenio (abemaciclib) is a dual CDK4/6 inhibitor, which inhibits Rb1 protein phosphorylation and may induce cell cycle arrest and prevent growth in cancer cells (PMID: 24919854). Verzenio (abemaciclib) is FDA approved as a monotherapy and in combination with Faslodex (fulvestrant) in patients with hormone receptor-positive (ESR, PGR) and ERBB2 (HER2) receptor-negative advanced or metastatic breast cancer (FDA.gov).
Hormone - Anti-estrogens
||Faslodex (fulvestrant) is a competitive inhibitor of estrogen that binds and deforms estrogen receptors, and causes inhibition of growth in cultured estrogen-sensitive breast cancer cells (NCI Drug Dictionary). Faslodex (fulvestrant) is FDA approved for use in patients with hormone receptor-positive breast cancer (FDA.gov).
HER2 (ERBB2) Antibody
||Herceptin (trastuzumab) is a monoclonal antibody, which binds ERBB2 (HER2) to induce tumor cellular cytotoxicity (PMID: 17611206). Herceptin (trastuzumab) is FDA approved for HER2-overexpressing (or amplification) breast cancer, gastric adenocarcinoma, and gastroesophageal junction adenocarcinoma (FDA.gov).