Sermonix Pharmaceuticals, founded by David Portman, MD, a leading clinical researcher and expert in women’s health, menopause, and selective estrogen receptor modulators (SERMs), focuses on developing innovative therapeutics to specifically treat ESR1-mutated metastatic breast and gynecological cancers. Our ELAINE-2 study is evaluating investigational lasofoxifene in combination with the CDK4/6 inhibitor abemaciclib for the treatment of metastatic breast cancer with an ESR1 mutation. Lasofoxifene’s bioavailability and activity in mutations of the estrogen receptor could potentially hold promise for patients who have acquired endocrine resistance due to ESR1 mutations, a common finding in the metastatic setting and an area of high unmet medical need. Lasofoxifene, the only SERM currently being developed exclusively to treat breast cancers with ESR1 mutations, could, if approved, play a critical role in the targeted precision medicine treatment of advanced ER+ breast cancer. Lasofoxifene’s novel activity in ESR1 mutations was discovered at Duke University, and Sermonix has exclusive rights to develop and commercialize lasofoxifene in this area.