LEXICON PHARMACEUTICALS REPORTS FOURTH QUARTER 2023 FINANCIAL RESULTS AND PROVIDES BUSINESS UPDATE Commercial launch of INPEFA (sotagliflozin) continues to progress. with increasing dem

LEXICON PHARMACEUTICALS REPORTS FOURTH QUARTER 2023

FINANCIAL RESULTS AND PROVIDES BUSINESS UPDATE

Commercial launch of INPEFA (sotagliflozin) continues to progress. with

increasing demand across the cardiology community and improving payer access

Patient enrollment underway in PROGRESS, a

Phase 2b study of LX9211 in Diabetic Peripheral Neuropathic Pain; topline data anticipated Q2 2025

Preparations underway for

Phase 3 study of sotagliflozin in Hypertrophic Cardiomyopathy and resubmission of NDA for sotagliflozin in Type 1 Diabetes

Recent Successful Capital Raise Supports Company Initiatives for Growth and Expansion

Company to Present at the Leerink Partners Global Biopharma Conference Tuesday, March 12th at 3:40 p.m. ET

The Woodlands, Texas, March 11, 2023 - Lexicon Pharmaceuticals, Inc. (Nasdaq: LXRX), today reported financial results for the three months ended

December 31, 2023 and provided an update on key corporate milestones.

2023 was a pivotal year for Lexicon, said Lonnel Coats,

Lexicon s chief executive officer. We launched INPEFA within weeks of receiving U.S. FDA approval with a broad label for heart failure, while in parallel continuing the advancement of our innovative research and development

In the fourth quarter, we saw continued progress on the launch of INPEFA and began to see increased prescriber demand and important

formulary wins, which we expect to accelerate in the first half of 2024. We advanced LX9211 into late-stage development for diabetic peripheral neuropathic pain (DPNP), with the potential to become the first new,

non-opioid drug approved for neuropathic pain in over two decades.

We are preparing for Phase 3

development of sotagliflozin in hypertrophic cardiomyopathy (HCM), an area of high unmet need with very few treatments in development. And following recent feedback from FDA, we are preparing to resubmit our New Drug Application (NDA) for

sotagliflozin as an adjunct to insulin therapy in patients with type 1 diabetes and chronic kidney disease. Our research and development engine also continues to produce, and we are conducting preclinical development on an oral small molecule

compound for obesity and weight management. With these opportunities and the support from shareholders in our recent successful financing, Lexicon is well positioned for growth and expansion in 2024 and beyond.

Fourth Quarter Highlights

INPEFA (sotagliflozin)

Publications and Data

Additional Pipeline Opportunities

Fourth Quarter 2023 Financial Highlights

Unless otherwise stated, all comparisons are for the fourth quarter and full year of 2023 compared to the fourth quarter and full year of 2022.

Revenues: Revenues for the fourth quarter and full year of 2023 were $0.7 million and $1.2 million, respectively, primarily from the

commercialization of INPEFA.

Research and Development (R&D) Expenses: Research and development expenses for the fourth quarter of 2023

increased to $14.8 million from $14.0 million for the corresponding period in 2022. Full-year research and development expenses increased to $58.9 million in 2023 from $52.8 million for the corresponding period in 2022, primarily

due to higher manufacturing costs, partially offset by lower professional and consulting fees related to the prior year NDA resubmission for heart failure.

Selling, General and Administrative (SG&A) Expenses: Selling, general and administrative expenses for the fourth quarter of 2023 increased to

$32.6 million from $16.3 million in 2022 and for the full-year 2023 increased to $114.0 million from $48.1 million in 2022. The increase in 2023 is primarily due to the significant investment in the commercial launch of INPEFA,

including higher salaries and benefits of the new sales force and other increased headcount, higher travel, and higher marketing costs.

Net loss for the fourth quarter of 2023 was $48.2 million, or $0.20 per share, as compared to a net loss of $30.5 million, or $0.16 per share, in the corresponding period in 2022. For the fourth quarters of 2023 and 2022, net loss included

non-cash, stock-based compensation expense of $3.2 million and $3.3 million, respectively. Net loss for the full year was $175.6 million, or $0.79 per share, in 2023 as compared to a net loss of

$101.9 million, or $0.62 per share, in the corresponding period in 2022. For the full years of 2023 and 2022, net loss included non-cash, stock-based compensation expense of $14.3 million and

$11.5 million, respectively.

Cash and Investments: As of December 31, 2023, Lexicon had $170.0 million in cash and investments, as

compared to $138.4 million as of December 31, 2022.

Lexicon 2024 Investor Day April 22, 2024

In lieu of a year-end earnings conference call, Lexicon plans to hold an Investor Day on April 22, 2024. The event will be webcast live on Lexicon s

website at www.lexpharma.com/events. The agenda will include a business and regulatory update, with participation from multiple physician experts in the areas of cardiometabolic disorders, HCM, type 1 diabetes and diabetic peripheral neuropathic

For Lexicon s latest investor presentation, please visit https://www.lexpharma.com/investors.

Planned Participation in Upcoming Investor Conferences:

These events will be webcast live on Lexicon s website at www.lexpharma.com/events

About INPEFA (sotagliflozin)

Discovered using Lexicon s unique approach to gene science, INPEFA (sotagliflozin) is an oral

inhibitor of two proteins responsible for glucose regulation known as sodium-glucose cotransporter types 2 and 1 (SGLT2 and SGLT1). SGLT2 is responsible for glucose and sodium reabsorption by the kidney and SGLT1 is responsible for glucose and

sodium absorption in the gastrointestinal tract. Sotagliflozin has been studied in multiple patient populations encompassing heart failure, diabetes, and chronic kidney disease in clinical studies involving approximately 20,000 patients.

INPEFA is indicated to reduce the risk of

cardiovascular death, hospitalization for heart failure, and urgent heart failure visit in adults with:

IMPORTANT SAFETY INFORMATION

Dosing: Assess renal

function and volume status and, if necessary, correct volume depletion prior to initiation of INPEFA. INPEFA dosing for patients with decompensated heart failure may begin when patients are hemodynamically stable, including when hospitalized or

immediately upon discharge.

Contraindications: INPEFA is contraindicated in patients with hypersensitivity to INPEFA or any of its components.

Ketoacidosis: INPEFA increases the risk of ketoacidosis in patients with type 1 diabetes mellitus (T1DM). Type 2 diabetes Mellitus (T2DM) and

pancreatic disorders are also risk factors. The risk of ketoacidosis may be greater with higher doses. There have been postmarketing reports of fatal events of ketoacidosis in patients with type 2 diabetes using sodium glucose transporter 2 (SGLT2)

inhibitors. Before initiating INPEFA, assess risk factors for ketoacidosis. Consider ketone monitoring in patients with T1DM and consider ketone monitoring in others at risk for ketoacidosis and educate patients on the signs/symptoms of

ketoacidosis. Patients receiving INPEFA may require monitoring and temporary discontinuation of therapy in clinical situations known to predispose to ketoacidosis. INPEFA is not indicated for glycemic control. Assess patients who present with signs

and symptoms of metabolic acidosis or ketoacidosis, regardless of blood glucose level. If suspected, discontinue INPEFA, evaluate, and treat promptly. Monitor patients for resolution of ketoacidosis before restarting INPEFA.

Volume Depletion: INPEFA can cause intravascular volume depletion which may sometimes manifest as symptomatic hypotension or acute transient changes in

creatinine. There have been post-marketing reports of acute kidney injury, some requiring hospitalization and dialysis, in patients with type 2 diabetes mellitus receiving SGLT2 inhibitors. Patients with impaired renal function (eGFR < 60

mL/min/1.73 m2), elderly patients, or patients on loop diuretics may be at increased risk for volume depletion or hypotension. Before initiating INPEFA in patients with one or more of these characteristics, assess volume status and renal function,

and monitor for signs and symptoms of hypotension during therapy.

Urosepsis and Pyelonephritis: Treatment with SGLT2 inhibitors, including INPEFA,

increases the risk for urinary tract infections. Serious urinary tract infections including urosepsis and pyelonephritis requiring hospitalization have been reported. Evaluate patients for signs and symptoms of urinary tract infections and treat

Hypoglycemia with Concomitant Use with Insulin and Insulin Secretagogues: Insulin and insulin

secretagogues are known to cause hypoglycemia. INPEFA may increase the risk of hypoglycemia when combined with insulin or an insulin secretagogue. Therefore, a lower dose of insulin or insulin secretagogue may be required to minimize the risk of

hypoglycemia when used with INPEFA.

Necrotizing Fasciitis of the Perineum (Fournier s Gangrene): Reports of Fournier s Gangrene, a rare

but serious and life-threatening necrotizing infection requiring urgent surgical intervention, have been identified in post-marketing surveillance in patients with diabetes mellitus receiving SGLT2 inhibitors. Assess patients who present with pain,

tenderness, erythema, or swelling in the genital or perineal area, along with fever or malaise. If suspected, start treatment immediately with broad-spectrum antibiotics and, if necessary, surgical debridement. Discontinue INPEFA, closely monitor

patient signs and symptoms, and provide appropriate alternative therapy for heart failure.

Genital Mycotic Infections: INPEFA increases the risk

of genital mycotic infections. Monitor and treat as appropriate.

Urinary Glucose Test and 1,5-anhydroglucitol (1,5-AG) Assay: these are not reliable for patients taking SGLT2 inhibitors. Use alternative testing methods to monitor glucose levels.

Common Adverse Reactions: the most commonly reported adverse reactions (incidence 5%) were urinary tract infection, volume depletion, diarrhea,

Click here for full Prescribing Information.

About Lexicon Pharmaceuticals

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 safely and effectively treat disease. Lexicon has advanced multiple medicines to market and has a pipeline of promising drug candidates in discovery and clinical and preclinical development in heart failure, neuropathic pain, diabetes

and metabolism and other indications. For additional information, please visit www.lexpharma.com.

Safe Harbor Statement

This press release contains forward-looking statements, including statements relating to Lexicon s financial position and long-term outlook

on its business, including the commercialization of its approved products and the clinical development of, regulatory filings for, and potential therapeutic and commercial potential of its other drug candidates. In addition, this press release also

contains forward looking statements relating to Lexicon s growth and future operating results, discovery, development and commercialization 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 its approved products, successfully conduct preclinical and clinical development and obtain necessary regulatory approvals of 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 approved

products and other 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, as 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.

Lexicon Pharmaceuticals, Inc.

Selected Financial Data