Sermonix announces case report during ELAINE-1 study of Lasofoxifene

Sermonix Pharmaceuticals announced that a case report detailing a durable complete remission during its Phase 2 ELAINE-1 study was published in JCO Precision Oncology. The case marks the first-ever known finding of a complete clinical remission in a metastatic estrogen receptor-positive/HER2- breast cancer patient with an ESR1 mutation after prior CDK4/6 inhibitor treatment upon participation in any single-agent hormonally based therapy trial. The open-access case report, “Lasofoxifene Monotherapy Induces Durable Complete Remission in a Patient with ER+, HER2- Metastatic Breast Cancer with an ESR1 Mutation,” details a patient result that was reported during Sermonix’s Evaluation of Lasofoxifene in ESR1 Mutations study. Sermonix licensed Lasofoxifene globally from Ligand Pharmaceuticals. The case was previously presented as a poster and brief talk at the annual Metastatic Breast Cancer Research Conference in September 2022. Topline results from the ELAINE-1 trial, including this patient, were reported at the European Society for Medical Oncology, ESMO, Congress 2022. “To witness a study participant with advanced breast cancer achieve a durable complete remission for more than two years while taking lasofoxifene is a reminder to everyone at Sermonix why we do what we do; it drives our daily and long-term vision for this drug,” said Dr. David Portman, Sermonix founder and chief executive officer. “We are excited the details of this complete responder – the only one to our knowledge achieved in the post-CDK4/6i-ESR1 mutation setting with single-agent endocrine therapy – will be shared with a broader audience through JCO Precision Oncology and we look forward to lasofoxifene’s continued clinical development during our current Phase 3 ELAINE-3 registrational study.”