COLUMBUS - Sermonix Pharmaceuticals Inc., a privately held biopharmaceutical company developing innovative therapeutics to specifically treat metastatic breast cancers harboring ESR1 mutations, and Shanghai Henlius Biotech, Inc. (2696.HK), today announced a strategic collaboration agreement in which Henlius will receive exclusive rights to develop, manufacture and commercialize Sermonix's lead investigational drug, lasofoxifene, in China.
Under the terms of the agreement, Henlius will receive exclusive rights and sublicenses to lasofoxifene for at least two estrogen receptor-positive (ER+)/HER2- breast cancer indications in the territory, with Sermonix retaining all other global rights. Sermonix received an upfront payment and is further eligible to receive up to $58 million in certain predetermined milestones, in addition to royalties upon Henlius commercialization in China.
'In Phase 2 clinical trials, investigational lasofoxifene demonstrated its potential for the treatment of ER+/HER2- breast cancer harboring ESR1 mutation,' said Ping Cao, senior vice president and chief business development officer of Henlius. 'Lasofoxifene will play a critical role in complementing Henlius' pipeline of its HER2+ breast cancer product. In collaboration with Sermonix, we look forward to accelerating the access of more effective, personalized, precise and well-tolerated treatment solutions for Chinese patients.'
'With a strong platform of R&D resources and commercialization capabilities, Henlius is an ideal partner to bring lasofoxifene into the therapeutic landscape in China,' said Dr. David Portman, Sermonix founder and chief executive officer. 'Previous studies demonstrated lasofoxifene's best-in-class potential and we will work with Henlius to accelerate the clinical development of the Phase 3 ELAINE-3 multi-regional clinical trial in China, making lasofoxifene available to Chinese patients as soon as possible.'
Breast cancer is the cancer with the highest incidence rate in the world, according to GLOBOCAN 2020. There were 2.26 million new cases of breast cancer in 2020 globally, including more than 410,000 in China [1]. ER+ breast cancer comprises 60-70% of all breast cancers [2]. Endocrine therapy remains the mainstay treatment for ER+ breast cancer and the most widely used class of aromatase inhibitor (AI) has been recommended by the National Comprehensive Cancer Network (NCCN) and Chinese Society of Clinical Oncology (CSCO) guidelines to be the adjuvant and first-line standard of care for patients with ER+/HER2- breast cancer [3-4]. However, almost all patients treated with AIs develop primary or acquired resistance [5], with acquired mutations in the estrogen receptor gene (ESR1) being the most prevalent (up to 40%). This is a significant mechanism of resistance to endocrine therapy[6]. Currently, there are limited treatment options for ER+/HER2- breast cancer with ESR1 mutations, and thus a large clinical need exists.
The Phase 3 ELAINE-3 multi-regional clinical trial (NCT05696626) is the third of Sermonix's Evaluation of Lasofoxifene in ESR1 Mutations (ELAINE) studies. With the Phase 2 ELAINE-1 and ELAINE-2 studies both completed and having shown compelling anti-tumor activity against tumors with increasingly prevalent ESR1 mutations [7-8], Sermonix in December 2023 activated and began enrollment for ELAINE-3 in the U.S.
ELAINE-3 will assess the efficacy of lasofoxifene and Eli Lilly and Company's (NYSE:lly) CDK4/6 inhibitor abemaciclib (Verzenio) compared to fulvestrant and abemaciclib in 400 pre- and post-menopausal subjects with locally advanced or metastatic ER+/HER2- breast cancer with an ESR1 mutation.
Henlius will fund the clinical development and patient enrollment of the ELAINE-3 study in China, and be responsible for regulatory approval and post-marketing manufacturing and commercialization in the region.
About Lasofoxifene
Lasofoxifene is an investigational novel endocrine therapy in clinical development which has demonstrated robust target engagement as an ESR1 antagonist in the breast, particularly in the presence of ESR1 mutations. Lasofoxifene has demonstrated anti-tumor activity as monotherapy and in combination with a CDK4/6 inhibitor in Phase 2 studies and has unique tissue selectivity distinguishing it from other current and investigational endocrine therapies, with beneficial effects seen on vagina and bone in previous clinical studies. Lasofoxifene, which Sermonix licensed globally from Ligand Pharmaceuticals Inc. (NASDAQ:LGND), has been studied in previous comprehensive Phase 1-3 non-oncology clinical trials in more than 15,000 postmenopausal women worldwide. 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's novel activity in ESR1 mutations was discovered at Duke University and Sermonix has exclusive rights to develop and commercialize the product in this area. Lasofoxifene, a novel targeted and tissue selective oral endocrine therapy could, if approved, play a critical role in the precision medicine treatment of advanced ER+ breast cancer.
About Sermonix
Sermonix Pharmaceuticals Inc. is a privately held biopharmaceutical company focused on the development of female-specific oncology products and is currently undertaking a Phase 3 clinical studies of lasofoxifene, its lead investigational drug. The Sermonix management team, led by founder Dr. David Portman, has significant experience in all stages of the drug development, regulatory and commercialization processes in the breast cancer drug development arena.
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