LGND Ligand Pharmaceuticals Incorporated

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 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 α 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 LasofoxifeneLasofoxifene 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 SermonixSermonix Pharmaceuticals Inc. is a privately held biopharmaceutical company focused on the development of female-specific oncology products and is currently undertaking two Phase 2 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. Paul Plourde, M.D., vice president of oncology clinical development, has many decades of experience at AstraZeneca in the breast cancer drug development arena. Barry Komm, Ph.D., chief scientific officer, is recognized for his expertise in nuclear receptor biology. Miriam Portman, M.D., is co-founder and chief operating officer, with expertise in clinical trial conduct and patient recruitment. Elizabeth Attias, M.M.Sc., Sc.D., chief strategy and development officer, has extensive experience in pharmaceutical drug development, strategic partnerships and commercialization. Simon Jenkins, Ph.D., vice president of operations, has over 30 years of experience in global drug development leadership. Sermonix non-executive chairman of the board is Anthony Wild, Ph.D., former president of both Parke-Davis Pharmaceuticals and Warner-Lambert’s Pharmaceutical Division. Learn more at SermonixPharma.com.

About HenliusHenlius (2696.HK) is a global biopharmaceutical company with the vision to offer high-quality, affordable, and innovative biologic medicines for patients worldwide with a focus on oncology, autoimmune diseases, and ophthalmic diseases. Up to date, 5 products have been launched in China, 2 has been approved for marketing in overseas markets, 19 indications are approved worldwide, and 3 marketing applications have been accepted for review in China, the U.S., and the EU, respectively. Since its inception in 2010, Henlius has built an integrated biopharmaceutical platform with core capabilities of high-efficiency and innovation embedded throughout the whole product life cycle including R&D, manufacturing and commercialization. It has established global innovation centers and Shanghai-based manufacturing facilities in line with global Good Manufacturing Practice (GMP), including Xuhui Facility and Songjiang First Plant, both certificated by China and the EU GMP.

Henlius has pro-actively built a diversified and high-quality product pipeline covering over 20 innovative monoclonal antibodies (mAbs) and has continued to explore immuno-oncology combination therapies with proprietary HANSIZHUANG (anti-PD-1 mAb) as backbone. Apart from the launched products HANLIKANG (rituximab), the first China-developed biosimilar, HANQUYOU (trastuzumab for injection, trade name in Europe: Zercepac®; trade names in Australia: Tuzucip® and Trastucip®), the first China-developed mAb biosimilar approved both in China and Europe, HANDAYUAN (adalimumab) and HANBEITAI (bevacizumab), the innovative product HANSIZHUANG has been approved by the NMPA for the treatment of MSI-H solid tumors, squamous non-small cell lung cancer (sqNSCLC) and extensive-stage small cell lung cancer (ES-SCLC), and esophageal squamous cell carcinoma (ESCC), making it the world's first anti-PD-1 mAb for the first-line treatment of SCLC. What's more, Henlius has conducted over 30 clinical studies for 16 products, expanding its presence in major markets as well as emerging markets.

References:[1] Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, Bray F. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and MortalityWorldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021 May;71(3):209-249.[2] Ignatiadis M, Sotiriou C. Luminal breast cancer: from biology to treatment[J]. Nat Rev Clin Oncol, 2013, 10(9): 494-506. doi: 10.1038/nrclinonc.2013.124.[3] Chinese Society of Clinical Oncology (CSCO) Breast Cancer Guidelines 2023[4] NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Breast Cancer V.5.2023[5] Rozeboom B, Dey N, De P. ER+ metastatic breast cancer: past, present, and a prescription for an apoptosis-targeted future. Am J Cancer Res. 2019;9(12):2821-2831. Published 2019 Dec 1.[6] Spoerke JM, Gendreau S, Walter K, et al. Heterogeneity and clinical significance of ESR1 mutations in ER-positive metastatic breast cancer patients receiving fulvestrant. Nat Commun. 2016;7:11579. Published 2016 May 13. doi:10.1038/ncomms11579[7] Goetz MP, Bagegni NA, Batist G, et al. Lasofoxifene versus fulvestrant for ER+/HER2- metastatic breast cancer with an ESR1 mutation: results from the randomized, phase II ELAINE 1 trial. Ann Oncol. 2023;34(12):1141-1151. doi:10.1016/j.annonc.2023.09.3104[8] S. Damodaran, C.C. O’Sullivan, A. Elkhanany, I.C. Anderson, M. Barve, S. Blau, M.A. Cherian, J.A. Peguero, M.P. Goetz, P.V. Plourde, D.J. Portman, H.C.F. Moore, Open-label, phase II, multicenter study of lasofoxifene plus abemaciclib for treating women with metastatic ER+/HER2− breast cancer and an ESR1 mutation after disease progression on prior therapies: ELAINE 2. Ann Oncol. 2023;34(12):1131-1140. doi:10.1016/j.annonc.2023.09.3103.

Sermonix Contact:Elizabeth Attias, Sc.D.Chief Strategy and Development OfficerEAttias@sermonixpharma.com(973) 723-7832

Henlius Contact:Bella Zhou/Janice HanPR@henlius.com