Tonix (NASDAQ: TNXP) shares Phase 1 TNX-4800 Lyme prevention results

Filing Impact

(High)

Filing Sentiment

(Neutral)

Form Type

8-K

Rhea-AI Filing Summary

Tonix Pharmaceuticals reported Phase 1 results for TNX-4800, an investigational long-acting monoclonal antibody designed to prevent Lyme disease. In 44 healthy volunteers, single subcutaneous doses showed a favorable safety profile, mostly mild injection-site reactions, and dose‑proportional pharmacokinetics with a mean half‑life of about 62–69 days. Serum levels were detectable within two days and remained quantifiable for up to 12 months in most participants, with exposure at the highest 10 mg/kg dose under 17% of peak levels seen in rat toxicology. Nonclinical primate data support protective serum thresholds, and modeling underpins a two‑dose regimen. Tonix plans an adaptive Phase 2 field study in 2027, pending FDA agreement, while highlighting approximately $185.5 million in cash and no debt as of March 31, 2026.

8-K Event Classification

3 items: 7.01, 8.01, 9.01

3 items

Item 7.01 Regulation FD Disclosure Disclosure

Material non-public information disclosed under Regulation Fair Disclosure, often investor presentations or guidance.

Item 8.01 Other Events Other

Voluntary disclosure of events the company deems important to shareholders but not covered by other items.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Key Figures

Cash balance: $185.5 M Debt: No debt FDA-approved products: 3 products +5 more

8 metrics

Cash balance $185.5 M Cash as of March 31, 2026

Debt No debt Capital structure as presented

FDA-approved products 3 products Number of approved products in portfolio

Phase 1 enrollment 44 volunteers Total participants in TNX-4800 Phase 1 trial

Treatment-emergent adverse events 61 TEAEs in 21/34 Reported TEAEs and proportion of treated participants

TNX-4800 half-life 62–69 days Mean half-life across Phase 1 dose groups

Protective serum level >21 μg/mL Primate model serum level associated with 95% protection

Planned MEC duration 136–265 days Modeled days above MEC thresholds after two 350 mg doses

Key Terms

Minimum Effective Concentration (MEC), treatment-emergent adverse events (TEAEs), anti-drug antibodies, Good Manufacturing Process (GMP), +2 more

6 terms

Minimum Effective Concentration (MEC) medical

"Analysis of Minimum Effective Concentration (MEC) – Three Methods"

treatment-emergent adverse events (TEAEs) medical

"Total of 61 TEAEs reported by 21/34 (62%) participants"

Adverse events that first appear or worsen after a patient starts a medical treatment; they are the new or intensified negative effects linked in time to taking the drug or therapy. Investors care because the number and severity of these events shape regulators’ decisions, drug labeling, patient uptake and potential legal or cost risks—think of them like customer complaints that can slow sales, trigger recalls, or change a product’s value.

anti-drug antibodies medical

"Transient ADAs were detected in 3/34 (9%) treated subjects"

Anti-drug antibodies are immune system proteins that form in patients in response to a biological therapy, such as a therapeutic protein or antibody, and can bind to the medicine. They matter to investors because they can reduce or eliminate a drug’s effectiveness, create safety problems, force higher dosing or additional testing, and influence regulatory approval and commercial success — like delivery guards accidentally intercepting and stopping a needed package.

Good Manufacturing Process (GMP) technical

"Manufacturing GMP Material for Human Studies Currently on Track for Early 2027"

Type C Meeting regulatory

"Scheduled Type C Meeting with the FDA to Discuss the Planned Ph 2 Study Design"

adaptive Phase 2 field study medical

"Plan to Initiate Adaptive Phase 2 Field Study, Pending FDA Agreement"

A mid-stage clinical trial conducted in real-world settings that tests whether a treatment works and helps identify the best dose while allowing pre-planned changes during the study based on early results. Think of it like adjusting a recipe while guests taste: researchers can fine-tune dosing or enrollment to improve chances of success. Investors care because this flexible approach can speed development and reduce costs, but it also adds regulatory and execution risk.

Understanding 8-K Material Events →

05/15/2026 - 09:25 AM

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of report (date of earliest event reported): May 15, 2026

TONIX PHARMACEUTICALS HOLDING CORP.

(Exact name of registrant as specified in its charter)

Nevada

001-36019

26-1434750

(State or Other Jurisdiction

of Incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

200 Connell Drive, Berkeley Heights, New Jersey, 07922

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (862) 799-8599

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock	TNXP	The NASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 7.01

Regulation FD Disclosure.

On May 15, 2026, Tonix Pharmaceuticals Holding Corp. (the “Company”) presented certain data from the Phase 1 trial for its TNX-4800 product candidate for protection against Lyme disease at the Global Lyme Alliance. A copy of the presentation is attached hereto as Exhibit 99.01.

The information in this Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.01 attached hereto, shall not be deemed “filed” for purposes of Section 18 of the United States Securities Exchange Act of 1934 (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall they be deemed incorporated by reference in any filing under the United States Securities Act of 1933 or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 8.01

Other Events.

On May 15, 2026, the Company presented the following analysis of pharmacokinetic data from the Phase 1 trial for TNX-4800 at the Global Lyme Alliance in connection with the proposed adaptive Phase 2 field study for TNX-4800, planned for the first half of 2027, pending agreement by the U.S. Food and Drug Administration:

•

Simulation of a two-dose regimen (350 mg subcutaneous administration on Day 1 and 56 Days) of TNX-4800 were presented that predict mean serum levels for participants in the field study. Predictions were quantified for the time in days for serum levels to decrease below four serum levels, referred to as Minimum Effective Concentrations (“MECs”), of 10 µg/mL , 15 µg/mL, 20 µg/mL and 5 µg/mL. Days to MEC were: MEC₁ (10 µg/mL): 196 days; MEC₂ (15 µg/mL): 161 days; MEC₃ (20 µg/mL): 136 days; MEC₄ (5 µg/mL): 265 days.

•

The simulations and predictions support the feasibility of a two-dose 350 mg regimen maintaining a minimal mean serum level above MEC 10 µg/mL for six months following the initial dose, the proposed primary endpoint for the field study.

Forward-Looking Statements

This Current Report on Form 8-K contains certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 and Private Securities Litigation Reform Act, as amended, including those relating to the Company’s product development, clinical trials, clinical and regulatory timelines, market opportunity, competitive position, possible or assumed future results of operations, business strategies, potential growth opportunities and other statement that are predictive in nature. These forward-looking statements are based on current expectations, estimates, forecasts and projections about the industry and markets in which we operate and management’s current beliefs and assumptions.

These statements may be identified by the use of forward-looking expressions, including, but not limited to, “expect,” “anticipate,” “intend,” “plan,” “believe,” “estimate,” “potential,” “predict,” “project,” “should,” “would” and similar expressions and the negatives of those terms. These statements relate to future events or our financial performance and involve known and unknown risks, uncertainties, and other factors which may cause actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Such factors include those set forth in the Company’s filings with the SEC. Prospective investors are cautioned not to place undue reliance on such forward-looking statements, which speak only as of the date of this press release. The Company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise.

Item 9.01

Financial Statements and Exhibits.

(d)

Exhibit

No.

Description.

99.01

TNX-4800: A Long-Acting, Bactericidal, Human Monoclonal Antibody to Prevent Lyme Disease in the U.S.

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURE

Pursuant to the requirement of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	TONIX PHARMACEUTICALS HOLDING CORP.

Date: May 15, 2026	By:	/s/ Bradley Saenger
		Bradley Saenger
		Chief Financial Officer

Tonix Pharmaceuticals Holding Corp. 8-K

Exhibit 99.01

© 2026 Tonix Pharmaceuticals Holding Corp. TNX - 4800: A Long - Acting, Bactericidal, Human Monoclonal Antibody to Prevent Lyme Disease in the U.S. Zeil Rosenberg MD, MPH Executive Vice President, Medical Tonix Pharmaceutical s Global Lyme Alliance PO6143 May 15, 2026 1660

2 © 2026 Tonix Pharmaceuticals Holding Corp. Cautionary Note on Forward - Looking Statements Certain statements in this presentation are forward - looking within the meaning of the Private Securities Litigation Reform Act of 1995. These statements may be identified by the use of forward - looking words such as “anticipate,” “believe,” “forecast,” “estimate,” “expect,” and “intend,” among others. These forward - looking statements are based on Tonix's current expectations and actual results could differ materially. There are a number of factors that could cause actual events to differ materially from those indicated by such forward - looking statements. These factors include, but are not limited to, risks related to the failure to successfully launch and commercialize TONMYA ® and any of our approved products; risks related to the failure to obtain FDA clearances or approvals and noncompliance with FDA regulations; risks related to the timing and progress of clinical development of our product candidates; our need for additional financing; uncertainties of patent protection and litigation; uncertainties of government or third party payor reimbursement; limited research and development efforts and dependence upon third parties; and substantial competition. As with any pharmaceutical under development, there are significant risks in the development, regulatory approval and commercialization of new products. Tonix does not undertake an obligation to update or revise any forward - looking statement. Investors should read the risk factors set forth in the Annual Report on Form 10 - K for the year ended December 31, 2025, as filed with the Securities and Exchange Commission (the “SEC”) on March 12, 2026, and periodic reports filed with the SEC on or after the date thereof. All of Tonix's forward - looking statements are expressly qualified by all such risk factors and other cautionary statements. The information set forth herein speaks only as of the date thereof.

© 2026 Tonix Pharmaceuticals Holding Corp. © 2026 Tonix Pharmaceuticals Holding Corp. Fully Integrated Tonix Pharmaceuticals – Transforming Medicine for the Future TNXP Therapeutic Areas of Focus: • CNS • Infectious Disease • Immunology • Rare Disease Partnerships with major Universities and the U.S. Federal Government 3 FDA Approved Products • ~$185.5 M cash as of March 31, 2026 • No debt • Research • Development • Manufacturing • Commercial

4 © 2026 Tonix Pharmaceuticals Holding Corp. First FDA - Approved Treatment for Fibromyalgia in Over 15 Years First - in - class, First - line Medicine Unique, Sublingual, Proprietary Formulation Supports: Efficacy, Absorption, and Tolerability TONMYA Distinct mechanism of action versus current therapies Robust efficacy Generally well - tolerated Current Treatments Limited approved and effective options High rate of patient and HCP dissatisfaction Off - label opioids often used TONMYA (cyclobenzaprine HCl sublingual tablets) is indicated for the treatment of fibromyalgia in adults

5 © 2026 Tonix Pharmaceuticals Holding Corp. Overlap of Fibromyalgia and Chronic Lyme Disease Fibromyalgia Chronic Lyme Disease Long COVID Fibromyalgia is a diagnosable condition in: x Long COVID x Chronic Lyme disease x Other Infection Associated Chronic Illness (IACI)

6 © 2026 Tonix Pharmaceuticals Holding Corp. Addressing the Lyme Disease Spectrum Treatment for Fibromyalgia associated with chronic Lyme Potential to prevent transmission with TNX - 4800 Borrelia Infection Risk Period: Living, working or traveling to Lyme - endemic areas Acute Lyme Disease Chronic Lyme Disease H Dinerman, Steer AC 1992 doi : 10.7326/0003 - 4819 - 117 - 4 - 281

7 © 2026 Tonix Pharmaceuticals Holding Corp. Introducing TNX - 4800 TNX - 4800 1,2 is a human anti - OspA monoclonal antibody ( HuMAb ) with engineered Fc domain for extended half - life, licensed from UMass Chan Medical School in 2025 (Formerly 2217LS) c Two - dose Regimen Two SC doses (day 1 and 56) expected to provide ≥ 6 months protection c Tick Attaches Infected tick feeds on protected individual c Antibody Ingested TNX - 4800 enters tick midgut via blood meal c OspA Binding Antibody binds OspA on Borrelia Expected Mechanism of Action c Transmission Blocked Bacteria killed or trapped in midgut — cannot reach human tissue TNX - 4800 provides passive immunity by directly supplying neutralizing antibodies, bypassing the need for a patient’s immune system to generate its own antibodies 1. TNX - 4800 is an investigational biologic and is not approved for any indication. 2. TNX - 4800 is protected by Issued US Patent US 10,457,721 , which is licensed from UMass Chan with expiry in January 2036 (with PTA), excluding any possible patent term extension.

8 © 2026 Tonix Pharmaceuticals Holding Corp. Clinical and Market Acceptance o f Monoclonal Antibody Preventive Treatments Monoclonal antibody prophylaxis has been approved for respiratory syncytial virus (RSV) and COVID - 19, including ENFLONSIA ( clesrovimab ), 1 BEYFORTUS ®) ,( n irsevimab ) 2 PEMGARDA ( pemivibart ) 3 1. Enflonsia . Prescribing information. Merck Sharp & Dohme LLC; 2025. 2. Beyfortus . Prescribing information. Sanofi; 2024. 3. Pemgarda . Prescribing information. Invivyd , Inc.; 2025.

9 © 2026 Tonix Pharmaceuticals Holding Corp. TNX - 4800 Long - acting anti - OspA Monoclonal Antibody Design E ngineered Fc domain (LS) binding to FcRn for an extended half - life that targets OspA of Borrelia burgdorferi 1 ,2 1. Schiller ZA, et al. J Clin Invest. 2021;131(11):e144843. 2. Wang Y, et al. J Infect Dis. 2016;214(2):205 - 211.

10 © 2026 Tonix Pharmaceuticals Holding Corp. TNX - 4800 is Not a Vaccine Limitations of OspA vaccines • Protection depends on titer of OspA at the moment the deer tick sucks blood • High - titer vaccine responses require onerous immunization schedule • Little or no “memory” response on Borrelia exposure • OspA - expressing Borrelia is sequestered in the tick midgut • Protection depends on patient’s immune status • Results in heterogeneous polyclonal antibody response to vaccine • “Titer” of polyclonal response has uncertain correlation with individual protection • Associated with typical side - effects of vaccination

11 © 2026 Tonix Pharmaceuticals Holding Corp. Prophylactic Monoclonal Antibody ( mAb ) Characteristics Potential attributes of anti - OspA mAb TNX - 4800 • Nearly - immediate protection (within 2 days) • Not reliant on patient’s immune status • Replaces heterogeneous polyclonal response of vaccine with homogeneous monoclonal agent with defined properties • Replaces “titer” of polyclonal response with quantifiable serum levels • Potential for quantifying serum mAb levels as immune correlate of protection • Avoids side - effects of vaccination

12 © 2026 Tonix Pharmaceuticals Holding Corp. Analysis of Minimum Effective Concentration (MEC) – Method # 1 – in vivo Primate Challenge Model Three Models for MEC determination used: • in vitro borreliacidal activity • in vitro tick feeding assays • in vivo NHP challenge

13 © 2026 Tonix Pharmaceuticals Holding Corp. Nonhuman Primate Challenge Model: Protocol and Protection by Dosage Level Day - 7 0 6 14 21 28 45 63 Serum Collection 1 Jacket Acclimation Tick Challenge Tissue Biopsy Culture Observations HuMAb Injection Study Design 1 : Results: • Dose escalation study: 4 cohorts, 1 irrelevant IgG control • 4 to 6 animals per cohort; challenged with 20 infected ticks • Seroconversion for IgG antibodies against B. burgdorferi was measured as an indicator of efficacy Irrelevant IgG Cohort 4 Cohort 3 Cohort 2 Cohort 1 Cohort 10 90 30 10 3 Dose (mg/kg) 0 100 100 83 100 Protection (%) N/A <0.001 <0.001 <0.001 <0.001 P value 1. Schiller ZA, et al. J Clin Invest . 2021;131(11):e1144843. HuMAb =human monoclonal antibody; IgG=immunoglobulin G.

14 © 2026 Tonix Pharmaceuticals Holding Corp. Analysis of Minimum Effective Concentration (MEC) – Three Methods 1. Wang Y, et al. J Infect Dis. 2016. 214(2):205 - 11. 2. Rogers RR et al , Antimicrobial Agents and Chemotherapy , Oct. 2004, p. 3670 – 3676. 3. Schiller ZA, et al. J Clin Invest . 2021;131(11):e144843. • Serum ~ 5 μ g/mL – in vitro bactericidal activity (not shown) • TNX - 4800 showed EC 50 ≈ 0.56 μ g/mL in vitro 1 • MEC ~ 10X EC 50 2 • Serum <10 μ g/mL – in vitro tick feeding experiment (not shown) • TNX - 4800 showed killing ≥ 10 μ g/ml 3 • Serum <21 μ g/mL – in vivo primate challenge model • TNX - 4800 serum levels >21 μ g/ml were 95% protective 1,3

16 © 2026 Tonix Pharmaceuticals Holding Corp. Human Phase 1 Study: Safety, Tolerability and Immunogenicity: Design Sullivan - Bólyai JZ, et al. Manuscript in progress. 2025. • First - in - human, randomized, double - blind, sequential dose - escalation study (N=44) • Healthy male and female volunteers aged 19 to 65 years, serum negative for anti – B. burgdorferi antibodies, by an FDA - approved modified 2 - tier ELISA test, were recruited • Safety was assessed via clinical and lab evaluations. Dose delivered SC. • Serum TNX - 4800 concentrations were measured by ELISA, with pharmacokinetic analysis • Antidrug antibodies were detected using an electrochemiluminescence immunoassay 1.5 mg/kg TNX - 4800 (N=8) Completed (N=41) Enrolled (N=44) 0.5 mg/kg TX - 4800 (N=10) 5.0 mg/kg TNX - 4800 (N=8) Cohort 1 Cohort 2 Cohort 3 10 mg/kg TNX - 4800 (N=8) Placebo (N=10) Cohort 4

17 © 2026 Tonix Pharmaceuticals Holding Corp. TNX - 4800 Phase 1 Study objectives and population Primary Objective : • Evaluate safety and tolerability of a SC injection of TNX - 4800 when administered to healthy volunteers Secondary Objective : • Evaluate pharmacokinetics of a SC dose of TNX - 4800 when administered to healthy volunteers Study Population : • Healthy male and female volunteers, age 19 to 65 years, inclusive • Median age of 39 years • 52% male and 48% female • White 77%, 16% African – American, non - Hispanic/Latino 91% • Seronegative to B. burgdorferi • Nebraska site to minimize prior limit existing Lyme immunity

18 © 2026 Tonix Pharmaceuticals Holding Corp. Phase 1 Safety Summary • 1 serious adverse event (SAE); in placebo group 1 • Total of 61 TEAEs reported by 21/34 (62%) participants compares to 3/10 (30%) in placebo • Large majority of drug related Treatment - Emergent Adverse Events (TEAEs) were mild (82%); remainder moderate (18%) • Transient ADAs were detected in 3/34 (9%) treated subjects, with no impact on PK • No safety signal or clustering of events observed TNX - 4800 was safe and well tolerated with no treatment - related serious adverse events and predominately mild adverse events 1 Celerion CSR CA29655 Table 14.3.2.1 (SAE Safety population)

19 © 2026 Tonix Pharmaceuticals Holding Corp. Related TEAE Summary 1 1 Celerion CSR CA29655 Table 14.3.1.3 (TEAE Safety Population) # Subjects Severity Grade Adverse Event 1 1 Dysgeusia 2 1 Feeling hot/ flush 7 1 Injection site reaction* 1 2 Injection site reaction 1 1 Palpitations 1 1 Paresthesia Severity Grading: Grade 1= Mild, Grade 2= Moderate, Grade 3= Severe, Grade 4= Life Threatening *Injection site reaction includes erythema, hemorrhage, edema, pain, pruritus

20 © 2026 Tonix Pharmaceuticals Holding Corp. Observed Phase 1 Pharmacokinetics 21 μ g/ml – ceiling for MEC from in vivo Primate challenge 56 days Each point represents a mean for the cohort at the specified timepoint and dose.

21 © 2026 Tonix Pharmaceuticals Holding Corp. Phase 1 Summary • No significant clinical or laboratory signals were identified at any dose level. • Drug exposure increased by approximately 25 times for a 20 - times increase in dose, indicating dose proportional PK. • Serum TNX - 4800 was measurable at two days, indicating rapid systemic absorption. • TNX - 4800 concentrations remained quantifiable for >200 days in 80% of volunteers at the lowest dose and for up to 350 days in the majority of volunteers at higher doses (i.e., ≥ 1.5 mg/kg). • Mean half - life ranged from 62 - 69 days across groups. Serum concentrations remained quantifiable for up to 12 months in most volunteers. Mean exposure for the 10 mg/kg cohort was less than 17% of the highest exposures in a rat toxicology study, indicating a wide safety margin. • Transient low levels of anti - drug antibodies were detected in 3 participants (<10% of treated volunteers) with no impact on PK. • Adverse events associated with the active were mild or moderate : injection site reactions(7) and feeling hot/flushed (2) were the most frequent • TNX - 4800 was safe and well tolerated

23 © 2026 Tonix Pharmaceuticals Holding Corp. Design of Planned Adaptive Phase 2 Field Study* in 2027 Study participants randomized 1:1 to receive TNX - 4800 or placebo Dose 1 Tick Season Day 1 Day 56 6 Months Dose 2 Surveillance *Pending FDA agreement.

24 © 2026 Tonix Pharmaceuticals Holding Corp. Mean Predictions: 350mg SC on Day 1 and 56 Days Preliminary Modeling 1000 10000 100000 0 50 100 150 200 250 300 350 400 Concentration [ng/mL] Time [days] TNX - 4800 (adjusted) Simulated Mean MEC1 MEC2 MEC3 Minimum Effective Concentration - 1 (MEC 1 )(10 µg/mL): 196 days; MEC 2 (15 µg/mL): 161 days; MEC 3 (20 µg/mL): 136 days and MEC4 (5 µg/mL): 265 days PK with 2 nd Dose 15 μ g/ml 10 μ g/ml Serum TNX - 4800 ( μ g/ml) 20 μ g/ml PK with 1 st Dose

25 © 2026 Tonix Pharmaceuticals Holding Corp. Planned Adaptive Phase 2 Field Trial 2027 Adaptive, randomized, double - blind, placebo - controlled study • Objective: • To evaluate the efficacy and safety of TNX - 4800 in preventing the first occurrence of confirmed Lyme disease during the primary efficacy surveillance period (Day 3 through Month 6 following administration) • Inclusion: • Adolescents and adults >16 years of age from Lyme - endemic areas in the U.S. • Primary endpoint: • Prevention of Lyme disease at six months (comparison of TNX - 4800 group and placebo group) • Dose: • Two SC doses of TNX - 4800 or placebo at day 1 and day 56 1. Average patient is assumed to be approximately 70kg. 2. Pending FDA agreement

26 © 2026 Tonix Pharmaceuticals Holding Corp. Addressing the Significant Public Health Challenge of Lyme Disease in the U.S. Manufacturing GMP Material for Human Studies Currently on Track for Early 2027 Plan to Initiate Adaptive Phase 2 Field Study, Pending FDA Agreement 2026 Early 3Q 2026 1H 2027 x Phase 1 study complete, showing favorable safety, tolerability, immunogenicity, and pharmacokinetics x Phase 2 adaptive field study planning and GMP manufacturing underway for 1H 2027 GMP = Good Manufacturing Process Scheduled Type C Meeting with the FDA to Discuss the Planned Ph 2 Study Design TNX - 4800 Upcoming Milestones

27 © 2026 Tonix Pharmaceuticals Holding Corp. Development of TNX - 4800 (formerly 2217 LS) ACKNOWLEDGEMENTS • Mark S. Klempner, MD • Yang Wang MD, PhD • William D. Thomas MD • Naomi K. Boatright PhD Inventors: UMass Chan School of Medicine • National Center for Advancing Translational Sciences (NCATS), NIH • DARPA • DOD Tick Borne Disease Research Program • NIAID, NIH Support (to U Mass Chan):

28 © 2026 Tonix Pharmaceuticals Holding Corp. Tonix Acknowledgements Tonix Pharmaceuticals: Seth Lederman MD Greg Sullivan MD Siobhan Fogarty MS Sina Bavari PhD Christopher Cooper PhD Hadi Falahatpisheh PhD Nita Patel PhD Agnes Meade PhD Jean Heilman MS Misha Chittoda Advisors/Consultants : Mark Klempner, MD Yang Wang, MD PhD Grace Chen - Phillips MD Phil Krause MD Cathy Panozzo PhD Bernd Meibohm , PhD Martha Nason PhD

30 © 2026 Tonix Pharmaceuticals Holding Corp. TONMYA Important Safety Information (ISI) Indication • Tonmya is indicated for the treatment of fibromyalgia in adults. Contraindications: • Hypersensitivity to cyclobenzaprine or any inactive ingredient in cyclobenzaprine HCl sublingual tablets • Concomitant use of monoamine oxidase inhibitors or within 14 days after their discontinuation • During acute recovery phase of myocardial infarction and in patients with arrhythmias, heart block or conduction disturbances , o r congestive heart failure • Hyperthyroidism Warnings and Precautions: • Embryofetal toxicity: Cyclobenzaprine HCl sublingual tablets may cause neural tube defects when used 2 weeks prior to concept ion and during the first trimester of pregnancy (animal data). Advise female patients of reproductive potential of the potential risk and to use effec tiv e contraception during treatment and for 2 weeks after the final dose. Perform a pregnancy test prior to initiation of treatment • Serotonin syndrome: Concomitant use of serotonergic drugs with cyclobenzaprine HCl sublingual tablets increases the risk of s ero tonin syndrome, which may be life threatening. Treatment with cyclobenzaprine sublingual HCl tablets and serotonergic drugs should be closely mo nitored, particularly during treatment initiation and dosage increases, and should be immediately discontinued if serotonin syndrome symptoms occur , i ncluding mental status changes, autonomic instability, neuromuscular abnormalities, and/or gastrointestinal symptoms • Tricyclic antidepressant - like adverse reactions: Given the structural similarity of cyclobenzaprine to tricyclic antidepressants (TCAs), discontinuation of cyclobenzaprine HCl sublingual tablets should be considered for patients experiencing clinically significant central nervous sys tem (CNS) symptoms, such as arrythmia, sinus tachycardia, myocardial infarctions, or stroke, and caution is advised for patients with a history o f s eizure disorder, as TCAs may lower the seizure threshold • Atropine - like adverse reactions: Caution is advised for patients with a history of urinary retention, angle - closure glaucoma, in creased intraocular pressure, and those taking anticholinergic drugs • CNS depression and risk of operating a motor vehicle or hazardous machinery: Cyclobenzaprine HCl sublingual tablets may cause CN S depression, which may be exacerbated by concomitant use of alcohol, barbiturates, or other CNS depressants. Patients should not operate m oto r vehicles/heavy machinery until they are reasonably certain that cyclobenzaprine HCl sublingual tablets will not impair their ability to oper ate them • Oral mucosal adverse reactions: The risk of oral sensory changes can be reduced by moistening the mouth with sips of water pr ior to administration of cyclobenzaprine HCl sublingual tablets

31 © 2026 Tonix Pharmaceuticals Holding Corp. TONMYA ISI (Continued) Drug Interactions: • Monoamine oxidase inhibitors: Life - threatening interactions may occur • Other serotonergic drugs: Serotonin syndrome has been reported • CNS depressants: CNS depressant effects of alcohol, barbiturates, and other CNS depressants may be enhanced • Tramadol: Seizure risk may be enhanced • Guanethidine or other similar acting drugs: The antihypertensive action of these drugs may be blocked Use in Specific Populations: • Pregnancy: Based on animal data, cyclobenzaprine HCl sublingual tablets may cause fetal harm when administered to a pregnant patient; pr egn ant women should be advised of the potential risk to the fetus and avoid use of cyclobenzaprine HCl sublingual tablets two weeks pri or to conception and through the first trimester of pregnancy • Lactation: There are no data on the effects of cyclobenzaprine on a breastfed infant, or the effects on milk production • Pediatric use: The safety and effectiveness of cyclobenzaprine HCl sublingual tablets have not been established • Geriatric patients: Clinical trials of cyclobenzaprine HCl sublingual tablets did not include sufficient numbers of patients ≥65 years of age to det ermine whether they respond differently from younger adult patients • Hepatic impairment (HI): The recommended dose of cyclobenzaprine HCl sublingual tablets in patients with mild HI (Child Pugh A) is 2.8 mg daily. The use of cyclobenzaprine HCl sublingual tablets is not recommended in patients with moderate or severe HI (Child Pugh B and C, respectively) due to increased adverse reaction risk • To report suspected adverse reactions, contact Tonix Medicines, Inc. at 1 - 888 - 869 - 7633, or the FDA at 1 - 800 - FDA - 1088 or www.fda.gov/medwatch.

Source: View Original Filing on SEC EDGAR

FAQ

What did Tonix (TNXP) disclose about TNX-4800 in this 8-K filing?

Tonix described Phase 1 data for TNX-4800, a long-acting monoclonal antibody to prevent Lyme disease. The study in 44 healthy volunteers showed favorable safety, dose-proportional pharmacokinetics, long half-life and measurable serum levels for many months, supporting a planned adaptive Phase 2 field trial.

How safe was TNX-4800 in Tonix (TNXP) Phase 1 results?

TNX-4800 was reported as safe and well tolerated with no treatment-related serious adverse events. Among 34 treated subjects, 61 treatment-emergent adverse events occurred in 21 participants, mostly mild injection-site reactions or feeling hot/flushed, and transient anti-drug antibodies in three subjects had no pharmacokinetic impact.

What pharmacokinetic profile did TNX-4800 show in the Tonix (TNXP) Phase 1 trial?

Serum TNX-4800 levels were measurable within two days of dosing and remained quantifiable for more than 200 days at the lowest dose. Across groups, mean half-life ranged from 62–69 days, with levels measurable for up to 12 months in most volunteers, indicating prolonged systemic exposure.

What are Tonix (TNXP) plans for TNX-4800 after completing Phase 1?

Tonix plans an adaptive, randomized, double-blind, placebo-controlled Phase 2 field study in 2027, pending FDA agreement. Participants aged over 16 in Lyme-endemic U.S. areas would receive two subcutaneous doses on days 1 and 56, with Lyme disease prevention at six months as the primary endpoint.

How much cash and debt does Tonix (TNXP) report in this presentation?

Tonix states it has approximately $185.5 million in cash as of March 31, 2026, and no debt. This cash position supports ongoing research, development, manufacturing and commercial activities, including further clinical development of TNX-4800 and other programs across its therapeutic focus areas.

What nonclinical data support TNX-4800’s potential Lyme protection for Tonix (TNXP)?

Nonhuman primate challenge studies linked serum TNX-4800 levels above about 21 μg/mL with 95% protection against Borrelia infection. Additional in vitro assays informed minimum effective concentration estimates, and together these models guided pharmacokinetic targets and dose simulations for the planned Phase 2 regimen.

Filing Exhibits & Attachments

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