First late-stage study will be a Phase 2b dose optimization study, with extension to run in parallel with next-stage Phase 3 studies Feedback obtained from U.S. Food and Drug Administration (FDA) Conference Call and Webcast on Monday, June 26, 2023, at 8:00 am Eastern Time THE WOODLANDS, Texas, June 23, 2023 (GLOBE NEWSWIRE) — Lexicon Pharmaceuticals, Inc. (Nasdaq: LXRX) today announced plans to advance its investigational drug LX9211 into late-stage development in a clinical program directed towards an application for regulatory approval in diabetic peripheral neuropathic pain, or DPNP. The first late-stage study will be a Phase 2b dose optimization study, with start-up scheduled in the third quarter of 2023 and the initiation of dosing expected in the fourth quarter. The Phase 2b study includes an extension to run in parallel with planned next-stage Phase 3 studies. Details of the clinical program, which has been designed to optimize opportunities for success, time, and efficiency in satisfying regulatory requirements for approval, will be shared in a Conference Call and Webcast on Monday, June 26, 2023, at 8:00 am ET. “We are energized by our interactions with the FDA and value the feedback we have received, which has helped to inform the design of our clinical program for LX9211,” said Craig Granowitz, M.D., Ph.D., Lexicon’s senior vice president and chief medical officer. “We look forward to advancing LX9211 towards regulatory approval for diabetic peripheral neuropathic pain.” LX9211 has received Fast Track designation from the U.S. Food and Drug Administration for development in DPNP. Conference Call and Webcast Information Lexicon management will hold a live conference call and webcast Monday, June 26, 2023, at 8:00 am ET / 7:00 am CT. The dial-in number for the conference call is 888-317-6003 and the conference ID for all callers is 7186279. The live webcast and replay may be accessed by visiting Lexicon’s website at www.lexpharma.com/events. An archived version of the webcast will be available on the website for 14 days. About Lexicon Pharmaceuticals Lexicon is a biopharmaceutical company with a mission of pioneering medicines that transform patients’ lives. Through its Genome5000™ program, Lexicon scientists studied the role and function of nearly 5,000 genes and identified more than 100 protein targets with significant therapeutic potential in a range of diseases. Through the precise targeting of these proteins, Lexicon is pioneering the discovery and development of innovative medicines to treat diseases safely and effectively. Lexicon is commercially launching one of these medicines, INPEFA™ (sotagliflozin), in the United States and has a pipeline of other promising drug candidates in discovery and preclinical and clinical development in neuropathic pain, diabetes and metabolism and other indications. For additional information, please visit www.lexpharma.com. About LX9211 Discovered using Lexicon’s unique approach to gene science, LX9211 is a potent, orally delivered, selective, investigational small molecule inhibitor of adaptor-associated kinase 1 (AAK1). Lexicon identified AAK1 in its target discovery efforts as a promising approach for the treatment of neuropathic pain and identified LX9211 and another development candidate in a neuroscience drug discovery alliance with Bristol-Myers Squibb from which Lexicon holds exclusive development and commercialization rights. Preclinical studies of LX9211 demonstrated central nervous system penetration and reduction in pain behavior in models of neuropathic pain without affecting opiate pathways. LX9211 has received Fast Track designation from the U.S. Food and Drug Administration for development in diabetic peripheral neuropathic pain. Safe Harbor Statement This press release contains “forward-looking statements,” including statements relating to the therapeutic and commercial potential, research and clinical development and regulatory status of LX9211. In addition, this press release also contains forward looking statements relating to Lexicon’s financial position and long-term outlook on its business, growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. All forward-looking statements are based on management’s current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including Lexicon’s ability to meet its capital requirements, successfully commercialize INPEFA™ (sotagliflozin) on the timeline and/or at the prices currently contemplated or at all, conduct preclinical and clinical development and obtain necessary regulatory approvals of INPEFA (in unapproved indications), LX9211 and its other drug candidates on its anticipated timelines, achieve its operational objectives, obtain patent protection for its discoveries and establish strategic alliances, as well as additional factors relating to manufacturing, intellectual property rights, and the therapeutic or commercial value of its drug candidates. Any of these risks, uncertainties and other factors may cause Lexicon’s actual results to be materially different from any future results expressed or implied by such forward-looking statements. Information identifying such important factors is contained under “Risk Factors” in Lexicon’s annual report on Form 10-K for the year ended December 31, 2022 and other subsequent disclosure documents filed with the Securities and Exchange Commission. Lexicon undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise. For Investor Inquiries:Carrie SiragusaLexicon Pharmaceuticals, Inc.csiragusa@lexpharma.com For Media Inquiries:Alina CocuzzaLexicon Pharmaceuticals, Inc.acocuzza@lexpharma.com