Lasofoxifene Tartrate

Acquired License to Phase 3 Lasofoxifene Development Program of Novel Selective Estrogen Receptor Modulator (SERM), a Potential Multi-Billion Dollar Opportunity as Treatment Option for Breast Cancer Patients with ESR1-Mutations Received Gross Proceeds of $90 Million in Private Placement Financing of Common Stock and Warrants with Cash-Exercisable Warrants Potentially Providing up to an Additional $146 Million to Support Development of Lasofoxifene Through Key Clinical and Regulatory Milestones Expect to Complete Enrollment of Phase 3 Clinical Trial of Lasofoxifene in ER-positive (ER+), HER2-negative, ESR1-mutated Metastatic Breast Cancer in 4Q 2026 with Topline Data Anticipated in 2H 2027 On-track to Initiate Phase 2 Proof-of-Concept Study of ATH-1105 in ALS patients in 2H 2026 BOTHELL, Wash., March 26, 2026 (GLOBE NEWSWIRE) -- LeonaBio, Inc. (NASDAQ: LONA), a clinical-stage biopharmaceutical company dedicated to the development of novel therapeutics for diseases with high unmet medical needs, today reported financial results for the year ended December 31, 2025, and provided recent pipeline and business updates. “2025 was a truly transformational year for LeonaBio. With our license for lasofoxifene, we added a late-stage drug candidate that has the potential to become the endocrine therapy of choice in the multi-billion-dollar second line metastatic breast cancer setting” stated Mark Litton, Ph.D., President and Chief Executive Officer of LeonaBio. “Coupled with our successful $90 million fundraise with the potential for $146 million in additional capital available through warrant exercises, we enter 2026 with the financial resources needed to advance both our oncology and neurodegeneration programs with confidence.” “Our transition from Athira Pharma to LeonaBio reflects far more than a name change; it represents our evolution into a more focused, diversified, and opportunity-driven biopharmaceutical company. We now have two clinical-stage programs and an experienced team aligned around focused execution. As we look ahead to meaningful clinical milestones in 2026 — including the anticipated completion of enrollment of the Phase 3 ELAINE-3 clinical trial and initiation of patient dosing in our ATH-1105 ALS program — we are energized by what lies ahead. We are building a company that we believe has the potential to change the treatment landscape for patients who urgently need better options, and I couldn’t be more optimistic about the momentum we carry into 2026 and beyond,” concluded Dr. Litton. Clinical Development & Pipeline Programs Lasofoxifene – A novel, nonsteroidal selective estrogen receptor modulator (SERM) with a unique binding profile, designed to confer potent activity against both wild-type and mutant estrogen receptors, including the clinically significant ESR1 mutations commonly associated with resistance to endocrine therapy in metastatic breast cancer. In December 2025, LeonaBio acquired an exclusive global license (excluding Asia and certain countries in the Middle East) from Sermonix Pharmaceuticals, Inc. for rights to develop and commercialize lasofoxifene. Lasofoxifene is being advanced in a Phase 3 clinical trial ( NCT05696626 ) in combination with abemaciclib, a CDK4/6 inhibitor, as a targeted therapy for estrogen receptor-positive (ER+), HER2-negative, ESR1-mutated metastatic breast cancer, a population with limited treatment options following progression on aromatase inhibitors and CDK4/6 inhibitors. The primary endpoint of the study is statistically significant improvement in progression free survival (PFS) as determined by blinded, independent central review (BICR). The ongoing Phase 3 trial aims to establish a new standard of care for this genetically defined patient group. LeonaBio is amending the ELAINE-3 trial protocol to increase the sample size from 500 participants to up to 600 participants. The primary goal of the amendment is to help ensure that the trial will have the appropriate number of disease progression events. The Company expects to complete enrollment of the Phase 3 ELAINE-3 clinical trial in the fourth quarter of 2026 and to have topline data in the second half of 2027. Lasofoxifene was previously evaluated in two Phase 2 studies in patients with ER+, HER2-negative locally advanced or metastatic breast cancer expressing an ESR1 mutation, ELAINE-1 and ELAINE-2 ELAINE-1, an open-label, randomized trial comparing lasofoxifene to fulvestrant, showed improved outcomes for lasofoxifene as a potential monotherapy. Although the trial was not powered, results included longer median progression-free survival (5.6 vs. 3.7 months), higher objective response rates (13.3% vs. 2.9%) and a durable complete response lasting more than 2.5 years. The treatment was well-tolerated with patients reporting quality-of-life benefits. ELAINE-2, an open-label study evaluating lasofoxifene in combination with abemaciclib, demonstrated clinical benefits in heavily pretreated patients, with a median progression-free survival of approximately 13 months, an objective response rate of 56% and a clinical benefit rate of 65.5%. The combination was generally well-tolerated with most adverse events being low grade. ATH-1105 – A novel, orally available, brain-penetrant, next-generation small molecule drug candidate designed to positively modulate the neurotrophic HGF system for potential treatment of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), Alzheimer’s disease, and Parkinson’s disease. ATH-1105 is currently being developed for the potential treatment of ALS. In August 2025, LeonaBio presented results from the first-in-human Phase 1 clinical trial ( NCT 06432647 ) of ATH-1105 in healthy volunteers at the ALS Nexus 2025 conference. Results from the Phase 1 trial demonstrated a favorable safety and tolerability pro well as dose-proportional pharmacokinetics and CNS penetration. Previously, the Company presented data from the Phase 1 clinical trial of ATH-1105 at the 4 th Annual ALS Drug Development Summit. Key highlights from the presentation included: ATH-1105 showed a favorable safety pro was well tolerated in both single and multiple ascending dose studies in healthy volunteers ATH-1105 showed dose proportional pharmacokinetics and central nervous system (CNS) penetration ATH-1105 demonstrated consistent and robust beneficial effects in preclinical models of ALS LeonaBio conducted the first-in-human Phase 1 double-blind, placebo-controlled clinical trial that enrolled 80 healthy volunteers to evaluate single and multiple oral ascending doses of ATH-1105. The study was completed in November 2024 and evaluated the safety and tolerability of ATH-1105 and included measurements of pharmacokinetic outcomes. ATH-1105’s potential is supported by a body of preclinical evidence demonstrating statistically significant improvements in nerve and motor function, biomarkers of inflammation and neurodegeneration, including neurofilament light chain and survival in various models of ALS. LeonaBio is on track to dose ALS patients in a Phase 2 proof-of-concept clinical trial in the second half of 2026. Corporate Updates In February 2026, Mark F. Kubik was appointed as Chief Business Officer of LeonaBio, with responsibility for licensing, partnership strategy and corporate development initiatives. In January 2026, LeonaBio changed its name from Athira Pharma to align with the Company’s transformative acquisition of rights to develop and commercialize lasofoxifene as a treatment for metastatic breast cancer and better reflect its commitment to continued leadership, resilience and innovation. In December 2026, the Company acquired an exclusive global license (excluding Asia and certain countries in the Middle East) from Sermonix Pharmaceuticals, Inc. for rights to develop and commercialize lasofoxifene, a selective estrogen receptor modulator (SERM) for the potential treatment of metastatic breast cancer. In conjunction with the Sermonix license agreement, LeonaBio announced a $90 million private placement financing of common stock and warrants, with the warrants providing, if exercised, up to an additional $146 million to support development through key clinical and regulatory milestones. Financial Results Cash Position. Cash, cash equivalents and investments were $88.3 million as of December 31, 2025, compared to $51.3 million as of December 31, 2024. Net cash used in operations was $45.7 million for the year ended December 31, 2025, compared to $97.2 million for the year ended December 31, 2024. Research and Development (R&D) Expenses. R&D expenses were $85.6 million for the year ended December 31, 2025, compared to $70.7 million for the year ended December 31, 2024. The increase was driven primarily by acquired in-process research and development costs related to our license of lasofoxifene. General and Administrative (G&A) Expenses. G&A expenses were $16.7 million for the year ended December 31, 2025, compared to $26.1 million for the year ended December 31, 2024. The decrease was driven primarily by a realization of cost efficiencies in 2025 as we pursued our strategic alternatives. Net Loss. Net loss was $105.6 million, or $24.70 per share, for the year ended December 31, 2025, compared to a net loss of $96.9 million, or $25.19 per share, for the year ended December 31, 2024. About LeonaBio LeonaBio, headquartered in the Seattle, Washington area, is a clinical-stage biopharmaceutical company dedicated to the development of novel therapeutics for diseases with high unmet medical needs, including treatment-resistant metastatic breast cancer and amyotrophic lateral sclerosis (ALS), with the goal of improving patients’ lives. Our lead drug candidates, lasofoxifene and ATH-1105, are novel, small molecule therapies with the potential to address devastating diseases where current treatment options are limited or ineffective. With a strong commitment to scientific excellence and patient-centered innovation, we are dedicated to developing meaningful new therapies for those who need them most. For more information, visit . Forward-Looking Statements This communication contains “forward-looking statements” within the meaning of Section 27A of the Securities Act, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995. These forward-looking statements are not based on historical fact and include statements regarding: the beneficial characteristics, safety and efficacy of LeonaBio’s drug candidates; the potential of any subsequent clinical trials to show the beneficial characteristics, safety and efficacy of ATH-1105; the potential of LeonaBio to complete the Phase 3 ELAINE-3 clinical trial for lasofoxifene and to meet the trial endpoints, and any subsequent clinical trials to show the clinical benefits of lasofoxifene; LeonaBio’s drug candidates as potential treatments for metastatic breast cancer, amyotrophic lateral sclerosis and other diseases; LeonaBio’s future development plans and the timing thereof; the potential learnings from preclinical studies and other nonclinical data and their ability to inform and improve future clinical development plans; LeonaBio’s ability to obtain regulatory approval for any of its product candidates and to successfully commercialize any approved products; the rate and degree of market acceptance of LeonaBio’s drug candidates, if approved for commercial use; the size and growth potential of the markets for LeonaBio’s drug candidates, if approved for commercial use, and LeonaBio’s ability to serve those markets; anticipated development milestone timelines, such as the initiation of clinical trials and the timing of data releases, and LeonaBio’s ability to meet such timelines; the potential for lasofoxifene to be a new standard of care in its target genetically defined patient group; LeonaBio’s ability to obtain and maintain regulatory approval of its drug candidates in the United States and other jurisdictions and the timing thereof, and any related restrictions, limitations or warnings in the label of any approved drug candidate; and the sufficiency of LeonaBio’s capital resources to advance both its oncology and neurodegeneration programs. Forward-looking statements generally include statements that are predictive in nature and depend upon or refer to future events or conditions, and include words such as “may,” “will,” “should,” “on track,” “would,” “expect,” “plan,” “believe,” “intend,” “pursue,” “continue,” “suggest,” “potential,” “target” and similar expressions. Any forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to, risks associated with the possible failure to realize certain anticipated benefits of the license relating to lasofoxifene and the recent private placement financing, including with respect to future financial and operating results; the data from preclinical and clinical trials may not support the safety, efficacy and tolerability of LeonaBio’s drug candidates; development of drug candidates may cease or be delayed; regulatory authorities could object to protocols, amendments and other submissions; future potential regulatory milestones for drug candidates, including those related to current and planned clinical studies, may be insufficient to support regulatory submissions or approval; whether LeonaBio’s trials are sufficiently powered to meet the planned endpoints; LeonaBio may not be able to recruit sufficient patients for its clinical trials; the outcome of legal proceedings that may in the future be instituted against LeonaBio, its directors and officers; possible negative interactions of LeonaBio’s drug candidates with other treatments; FDA regulatory delays and uncertainty and new policies, including executive orders, changes in the leadership of federal agencies such as the FDA and SEC, staff layoffs, budget cuts to agency programs and research and changes in drug pricing controls; LeonaBio’s assumptions regarding its financial condition and the sufficiency of its cash, cash equivalents and investments to fund its planned operations may be incorrect; adverse conditions in the general domestic and global economic markets, including as a result of tariffs; the impact of competition; the impact of drug candidate development and clinical activities on operating expenses; the impact of new or changing laws and regulations; as well as the other risks detailed in LeonaBio’s filings with the SEC from time to time. These forward-looking statements speak only as of the date hereof and LeonaBio undertakes no obligation to update forward-looking statements. LeonaBio may not actually achieve the plans, intentions or expectations disclosed in its forward-looking statements, and you should not place undue reliance on the forward-looking statements. Investor & Media Contact: Julie Rathbun LeonaBio Julie.rathbun@leonabio.com 206-769-9219 LeonaBio, Inc. Condensed Consolidated Balance Sheets (Amounts in thousands) December 31, December 31, 2025 2024 (unaudited) Assets Cash and cash equivalents $ 69,276 $ 48,438 Short-term investments 19,055 2,837 Other short-term assets 1,127 3,566 Other long-term assets 2,693 3,938 Total assets $ 92,151 $ 58,779 Liabilities and stockholders' equity Current liabilities $ 10,015 $ 13,135 Sermonix pre-funded warrant 37,488 — Milestone liability 15,116 — Long-term liabilities 1,742 803 Total liabilities 64,361 13,938 Stockholders' equity 27,790 44,841 Total liabilities and stockholders' equity $ 92,151 $ 58,779 LeonaBio, Inc. Condensed Consolidated Statements of Operations and Comprehensive Loss (Amounts in thousands, except share and per share amounts) Year Ended December 31, 2025 2024 Operating expenses: Research and development $ 17,500 $ 70,682 Acquired in-process research and development 68,088 — General and administrative 16,678 26,093 Legal expense — 4,127 Total operating expenses 102,266 100,902 Loss from operations (102,266 ) (100,902 ) Other income, net 1,236 3,962 Sermonix pre-funded warrant change in fair value (4,579 ) — Net loss $ (105,609 ) $ (96,940 ) Unrealized (loss) gain on available-for-sale securities (5 ) 350 Comprehensive loss attributable to common stockholders $ (105,614 ) $ (96,590 ) Net loss per share attributable to common stockholders, basic and diluted $ (24.70 ) $ (25.19 ) Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 4,275,762 3,848,044

点击蓝字，关注我们 张蓝心，高子慧，李宁，韩佳鹏，赵作伟，李曼 大连医科大学附属第二医院 HR阳性HER2阴性乳腺癌是最常见的乳腺癌亚型，内分泌治疗为其核心治疗手段，近年来治疗格局已转向内分泌为基础、靶向联合为增益的综合管理模式。本文结合2025年重要研究进展，围绕10个关键热点问题，系统综述该亚型乳腺癌不同治疗阶段的循证医学证据及临床决策。在早期新辅助治疗中，内分泌治疗与化疗在特定人群中疗效相近，CDK4/6抑制剂联合内分泌治疗展现出生物学抑制效应，新型药物如拉索昔芬、吉瑞司群、抗体缀合药物和免疫治疗等丰富了术前治疗选择，但尚未重塑治疗格局。早期辅助治疗强调基于复发风险分层的个体化策略，SOFT和TEXT研究15年随访结果巩固了卵巢功能抑制联合芳香化酶抑制剂在绝经前中高风险患者中的长期获益；阿贝西利、瑞波西利、达尔西利等CDK4/6抑制剂的长期随访数据确立了其在中高风险患者辅助强化治疗中的核心地位，lidERA研究则证实口服选择性雌激素受体降解剂吉瑞司群优于传统内分泌治疗，成为中高风险患者新的选择。晚期患者一线治疗中，3种CDK4/6抑制剂联合内分泌治疗效果相当，PI3Kα抑制剂联合方案为PIK3CA突变的内分泌耐药人群带来获益；循环肿瘤DNA监测ESR1突变实现早识别、早换药，推动治疗向动态精准管理转变。CDK4/6抑制剂后二线治疗基于分子分层的通路导向策略成为主流，PI3K-AKT-mTOR通路抑制剂联合方案为该通路异常患者提供有效的选择，口服选择性雌激素受体降解剂及其联合策略是ESR1突变患者的关键治疗方向，PI3K和mTOR双靶点抑制剂为PIK3CA野生型患者带来新的希望。综上，过去一年的研究进展逐步推动HR阳性HER2阴性乳腺癌治疗向精准化、动态化转型，未来随着更多靶点的发现与新型药物的研发，个体化治疗体系将不断完善，可望为患者带来更持久的疾病控制效果与长期生存获益。 通信作者：赵作伟，李曼 原文标题：2025年HR+/HER2-乳腺癌内分泌治疗研究热点及展望 原文参见：中国癌症杂志. 2026;36(2):131-140. （来源：SIBCS） 声 明 凡署名原创的文章版权属《肿瘤瞭望》所有，欢迎分享、转载。本文仅供医疗卫生专业人士了解最新医药资讯参考使用，不代表本平台观点。该等信息不能以任何方式取代专业的医疗指导，也不应被视为诊疗建议，如果该信息被用于资讯以外的目的，本站及作者不承担相关责任。