Sermonix Pharmaceuticals and Shanghai Henlius Biotech, Inc. have announced the dosing of the first Chinese patient in the Phase 3 ELAINE-3 trial. This global study is designed to evaluate the efficacy of oral lasofoxifene (HLX78 in China) in combination with Eli Lilly and Company’s CDK4/6 inhibitor, abemaciclib (Verzenio®), compared to fulvestrant and abemaciclib in patients with locally advanced or metastatic ER+/HER2- breast cancer harboring an ESR1 mutation.
The ELAINE-3 trial (NCT05696626), formally known as the third Evaluation of Lasofoxifene in ESR1 Mutations (ELAINE) trial, is actively recruiting participants across multiple countries, including China, the U.S., Canada, Israel, and the European Union. The trial aims to enroll 400 pre- and post-menopausal women.
Rationale for Lasofoxifene in ESR1-Mutated Breast Cancer
ESR1 mutations are a common mechanism of acquired endocrine resistance in metastatic ER+ breast cancer. Lasofoxifene is an investigational selective estrogen receptor modulator (SERM) with a unique ability to antagonize the estrogen receptor in the presence of these mutations. Previous Phase 2 studies (ELAINE-1 and ELAINE-2) have demonstrated that lasofoxifene exhibits anti-tumor activity against tumors with ESR1 mutations, both as a monotherapy and in combination with abemaciclib.
Potential Clinical Benefits
Lasofoxifene's bioavailability and activity against estrogen receptor mutations, coupled with its potential to improve sexual and urogenital health with a favorable safety profile, suggest it could offer a significant advantage for patients who have developed endocrine resistance. If approved, lasofoxifene could play a crucial role in the precision medicine treatment of advanced ER+ breast cancer.
Management Perspective
"The dosing of the first Chinese ELAINE-3 patient marks an important moment for Sermonix and Henlius as we work together to fully explore the potential of oral lasofoxifene in a diverse population," said Dr. David Portman, Sermonix founder and chief executive officer. "Our goal is to help as many people as possible to better confront breast cancer while maintaining their quality of life. This is another key step in that process."
