# EDGAR Filing Document

**Accession Number:** 0001430306
**File Stem:** 0001999371-26-008771
**Filing Date:** 2026-4
**Character Count:** 23691
**Document Hash:** 1c7eef766415accbb52228ce1c5828f2
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001999371-26-008771.hdr.sgml**: 20260423

**ACCESSION NUMBER**: 0001999371-26-008771

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 17

**CONFORMED PERIOD OF REPORT**: 20260421

**ITEM INFORMATION**: Regulation FD Disclosure

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260423

**DATE AS OF CHANGE**: 20260423

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Tonix Pharmaceuticals Holding Corp.
- **CENTRAL INDEX KEY:** 0001430306
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 261434750
- **STATE OF INCORPORATION:** NV
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36019
- **FILM NUMBER:** 26885522

**BUSINESS ADDRESS:**
- **STREET 1:** 200 CONNELL DRIVE, SUITE 3100
- **CITY:** BERKELEY HEIGHTS
- **STATE:** NJ
- **ZIP:** 07922
- **BUSINESS PHONE:** 212-980-9155

**MAIL ADDRESS:**
- **STREET 1:** 200 CONNELL DRIVE, SUITE 3100
- **CITY:** BERKELEY HEIGHTS
- **STATE:** NJ
- **ZIP:** 07922

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** TAMANDARE EXPLORATIONS INC.
- **DATE OF NAME CHANGE:** 20080320

?xml version='1.0' encoding='ASCII'?

**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): April 21, 2026**

**TONIX PHARMACEUTICALS HOLDING CORP.**

**(Exact name of registrant as specified in its charter)**

---

| | | |
|:---|:---|:---|
| **Nevada** | **001-36019** | **26-1434750** |
| **(State or Other Jurisdiction** <br> **of Incorporation)**  | **(Commission** <br> **File Number)** | **(IRS Employer** <br> **Identification No.)**  |

---

200 Connell Drive, Suite 3100, 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 April 23, 2026, Tonix Pharmaceuticals Holding Corp. (the "Company") announced an oral presentation and two poster presentations at the American Association for Cancer Research ("AACR") Annual Meeting 2026, held April 17-22, 2026. A copy of the press release that discusses this matter is attached hereto as Exhibit 99.01. Copies of the posters are attached hereto as Exhibits 99.02 and 99.03.

The information in this Item 7.01 of this Current Report on Form 8-K, including Exhibits 99.01, 99.02 and 99.03 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 April 21, 2026, the Company's collaborators at Columbia University presented an oral presentation on the Company's preclinical TNX-1700 program at the AACR entitled *TFF2 Deficiency Amplifies IL-1β–Driven Inflammation and Promotes Aging-Associated Gastric Tumor Progression*, which reviewed the results of a preclinical study comparing TFF2-expressing epithelial cells in the stomachs of aged and young mice, which were observed to be reduced in aged mice, with corresponding reductions in tissue and circulating TFF2 levels. Decline of TFF2 led to elevated IL-1β and promoted gastric inflammaging. Findings demonstrate that the murine version of TNX-1700 (mTNX-1700), a fusion protein of murine TFF2-murine albumin, reversed aging-associated inflammation in the mouse model. The stomachs of the aged mice exhibited increased susceptibility to tumor progression. Myeloid-derived suppressor cells accumulated and overexpressed IL-1β, interacting with IL-1R1⁺ cancer-associated fibroblasts. mTNX-1700 attenuated tumor progression in the aged gastric microenvironment.

The Company presented the poster entitled *In Vitro Characterization of Fully Human Antagonistic Anti-BTLA Monoclonal Antibodies*, which reviews B and T Lymphocyte Attenuator ("BTLA") role as a potential target in immuno-oncology since its ligand herpesvirus entry mediator is expressed in and upregulated in the tumor microenvironment of many cancers and generally correlates with reduced overall survival. The Company believes that targeting BTLA offers opportunities for cancer immunotherapy and has the potential to demonstrate additive or synergistic activity when combined with other checkpoint antagonists, potentially overcoming resistance mechanisms and improving clinical outcomes. The Company studied four potent, high affinity, human/cyno cross-reactive, human antagonistic anti-BTLA monoclonal antibodies. Three antagonists had reduced FcgRI binding and no binding to FcgRIIB compared to an antibody control, which the Company believes has the potential to improve pharmacokinetics and confer a reduced risk of FcR-dependent adverse events, such as cytokine release syndrome or other immune-mediated toxicities.

The second poster presentation, entitled *Pharmacokinetics of TNX-1700 in Non-Human Primates and Human FcRn/Serum Albumin Transgenic Mice*, which evaluates the Company's TNX-1700 product candidate for the treatment of gastric and colorectal cancer in combination with PD-1 blockade in non-human primates and double-transgenic mice expressing human FcRn and human serum albumin. All animals survived without clinical signs or greater than 10% body-weight loss. TNX-1700 exhibited dose-independent, linear pharmacokinetics, with comparable pharmacokinetic profiles and exposure observed across species and doses. TNX-1700 was found to extend the half-life of TFF2 and achieved durable systemic exposure. The Company believes this supports its potential as a therapeutic candidate for gastric cancer. *In Vitro Characterization of Fully Human Antagonistic Anti-BTLA Monoclonal Antibodies*, reviews B and T Lymphocyte Attenuator ("BTLA") role as a potential target in immuno-oncology since its ligand herpesvirus entry mediator is expressed in and upregulated in the tumor microenvironment of many cancers and generally correlates with reduced overall survival. The Company believes that targeting BTLA offers opportunities for cancer immunotherapy and has the potential to demonstrate additive or synergistic activity when combined with other checkpoint antagonists, potentially overcoming resistance mechanisms and improving clinical outcomes. The Company studied TNX-4700, its product candidate for the treatment of cancer, four potent, high affinity, human/cyno cross-reactive, human antagonistic anti-BTLA monoclonal antibodies. Three antagonists had reduced FcgRI binding and no binding to FcgRIIB compared to an antibody control, which the Company believes has the potential to improve pharmacokinetics and confer a reduced risk of FcR-dependent adverse events, such as cytokine release syndrome or other immune-mediated toxicities.

*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 | [Press Release of the Company, dated April 23, 2026](ex99-01.htm) |
|  | 99.02 | [In Vitro Characterization of Fully Human Antagonistic Anti-BTLA Monoclonal Antibodies](ex99-02.htm) |
|  | 99.03 | [Pharmacokinetics of TNX-1700 in Non-Human Primates and Human FcRn/Serum Albumin Transgenic Mice](ex99-03.htm) |
|  | 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.** | **TONIX PHARMACEUTICALS HOLDING CORP.** |
| Date: April 23, 2026 | By: | /s/ Bradley Saenger |
|  |  | Bradley Saenger |
|  |  | Chief Financial Officer |

---

## Exhibit 99.01

[TONIX PHARMACEUTICALS HOLDING CORP. 8-K](tnxp_8k-042226.htm)

**Exhibit 99.1**

![Tonix Pharmaceuticals - Wikipedia](ex99-01_01.jpg)

**Tonix Pharmaceuticals Presents Updates on Preclinical Immuno-Oncology Programs<br> at the American Association for Cancer Research (AACR) Annual Meeting 2026**

*TNX-1700 (TFF2-albumin fusion protein) reversed aging-associated gastric inflammation and<br> significantly attenuated tumor progression in aged gastric microenvironment in preclinical models*

*TNX-1700 exhibited dose-independent, linear pharmacokinetics in animals*

*TNX-4700 (human anti-BTLA monoclonal antibody) demonstrated potent, high-affinity binding and functional antagonism* 

BERKELEY HEIGHTS, N.J., April 23, 2026 (GLOBE NEWSWIRE) -- Tonix Pharmaceuticals Holding Corp. (Nasdaq: TNXP) ("Tonix" or the "Company"), a fully integrated, commercial biotechnology company, today announced an oral presentation and two poster presentations on its preclinical immuno-oncology portfolio at the American Association for Cancer Research (AACR) Annual Meeting 2026, held April 17-22, 2026, in San Diego, California.

"We are pleased to report encouraging preclinical data on our TFF2-albumin fusion protein (TNX-1700) and our anti-BTLA monoclonal antibody (mAb) (TNX-4700) at AACR," said Bruce Daugherty, PhD, MBA, Executive Vice President of Research at Tonix Pharmaceuticals. "TNX-1700 and TNX-4700 are investigational immuno-oncology candidates in pre-clinical development. TNX-1700 is in development for the treatment of gastric and colorectal cancer in combination with PD-1 inhibitors. TNX-4700 is in development for the treatment of potentially several cancers since its ligand HVEM is expressed and/or upregulated in the tumor microenvironment and generally correlates with reduced overall survival."

**Abstract #: 6822 Oral Presentation: "TFF2 Deficiency Amplifies IL-1β–Driven Inflammation and Promotes Aging-Associated Gastric Tumor Progression"**

&nbsp;&nbsp;&nbsp;&nbsp;· Presenting author: Shuang Li, MD, PhD, Postdoctoral Research
Scientist in the Timothy C. Wang, MD, Laboratory at the Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center

Aging is a major risk factor for gastric cancer, but the underlying mechanisms remain poorly defined. The stomach undergoes profound epithelial and immune remodeling during aging. TFF2 is a mucosal protective factor implicated in epithelial repair and immune regulation. However, whether TFF2 regulates age-associated inflammation and tumor progression remains unknown.

TFF2-expressing epithelial cells were reduced in the stomachs of aged mice compared to young mice, with corresponding reductions in tissue and circulating TFF2 levels. Decline of TFF2 led to elevated IL-1β and promoted gastric inflammaging. The murine version of TNX-1700 (mTNX-1700 or TFF2-MSA) treatment reversed aging-associated inflammation. The aged stomach exhibited increased susceptibility to tumor progression. Myeloid-derived stem cells (MDSCs) accumulated and overexpressed IL-1β, interacting with IL-1R1⁺ cancer associated fibroblasts (CAFs). mTNX-1700 attenuated tumor progression in the aged gastric microenvironment.

**Poster Presentation #7940: "Pharmacokinetics of TNX-1700 in Non-Human Primates and Human FcRn/Serum Albumin Transgenic Mice"**

&nbsp;&nbsp;&nbsp;&nbsp;· Presenting author: Bruce Daugherty, PhD, MBA, Executive
Vice President of Research, Tonix

TNX-1700 was evaluated in double-transgenic mice expressing human FcRn and human serum albumin (HSA) and in non-human primates. All animals survived without clinical signs or greater than 10% body-weight loss. TNX-1700 exhibited dose-independent, linear pharmacokinetics, with comparable pharmacokinetic profiles and exposure observed across species and doses. TNX-1700 substantially extends the half-life of TFF2 and achieves durable systemic exposure, supporting its potential as a therapeutic candidate for gastric cancer.

![Tonix Pharmaceuticals - Wikipedia](ex99-01_01.jpg)

**Poster Presentation #6550: *In Vitro* Characterization of Fully Human Antagonistic Anti-BTLA Monoclonal Antibodies**

&nbsp;&nbsp;&nbsp;&nbsp;· Presenting author: Bruce Daugherty, PhD, MBA, Executive
Vice President of Research, Tonix

B and T Lymphocyte Attenuator (BTLA) is a promising target in immuno-oncology since its ligand HVEM (herpesvirus entry mediator) is expressed in and upregulated in the tumor microenvironment of many cancers and generally correlates with reduced overall survival. Targeting BTLA offers opportunities for cancer immunotherapy and may demonstrate additive or synergistic activity when combined with other checkpoint antagonists, potentially overcoming resistance mechanisms and improving clinical outcomes.

Tonix studied several anti-BTLA mAbs, which demonstrated potent, high-affinity binding and functional antagonism of BTLA *in vitro*. Antagonists with reduced FcgRI binding and no binding to FcgRIIB may improve pharmacokinetics and confer a reduced risk of FcR-dependent adverse events, such as cytokine release syndrome or other immune-mediated toxicities.

Copies of the two poster presentations are available under the Scientific Presentations tab on the Tonix website at www.tonixpharma.com.

**About Trefoil Factor Family Member 2 (TFF2)**

Human TFF2 is a secreted protein expressed in gastrointestinal mucosa where it functions to protect and repair the mucosal lining. In gastric cancer, TFF2 is epigenetically silenced, and TFF2 is suggested to be protective against cancer development through several mechanisms, including its activity as a partial agonist of CXCR4 that modulates myeloid cell trafficking to reduce accumulation of immunosuppressive neutrophils.

**About TNX-1700**

TNX-1700, a fusion protein of TFF2 and albumin, is in preclinical and pre-Investigational New Drug (IND) stage of development as a treatment of gastric and colorectal cancer in combination with PD-1 blockade.<sup>1</sup> The Company in-licensed TFF2 technology from Columbia University. TNX-1700 is an immunotherapy being developed to treat gastric and colorectal cancers in combination with PD-1 blockers. Results of preclinical testing demonstrated that a mouse version of TNX-1700 was able to evoke an increase in anti-tumor immunity in combination with anti-PD-1 in several mouse models of gastric cancer by reducing immunosuppressive neutrophils and activating anti-tumoral CD8+ T cell responses. TNX-1700 administered as both monotherapy and in combination with anti-PD-1 dramatically reduced metastasis and increased survival in these models; these findings were recently published.<sup>1</sup> TNX-1700 addresses a central mechanism of therapeutic resistance to anti-PD-1 therapy in gastric cancer by targeting the CXCR4-driven myeloid axis to normalize cancer-induced myelopoiesis and reprogram the tumor microenvironment.

**About BTLA**

BTLA (B and T lymphocyte attenuator) is a protein on the surface of tumor infiltrating lymphocytes. Targeting BTLA is a promising target in immuno-oncology since its ligand HVEM is expressed and/or upregulated in the tumor microenvironment of many cancers including melanoma, non-small cell lung cancer, colorectal cancer, gastric cancer, glioblastoma, and prostate cancer and generally correlates with reduced overall survival. Targeting BTLA offers opportunities for cancer immunotherapy and may demonstrate additive or synergistic effects when combined with other checkpoint antagonists, potentially overcoming resistance mechanisms and improving clinical outcomes.

**About TNX-4700**

Tonix is developing TNX-4700 (anti-BTLA) mAb for immuno-oncology indications. The mAb technology was licensed from Curia.

**Citations:**

&nbsp;&nbsp;&nbsp;&nbsp;1. Qian J, et al. *Cancer Cell*. 2025. 43(8):1512-1529.e11.

![Tonix Pharmaceuticals - Wikipedia](ex99-01_01.jpg)

**Tonix Pharmaceuticals Holding Corp.**

Tonix Pharmaceuticals\* is a fully integrated, commercial-stage biotechnology company focused on central nervous system (CNS) and immunology treatments in areas of high unmet medical need. TONMYA® (cyclobenzaprine HCl sublingual tablets 2.8 mg), is the first new treatment for fibromyalgia in adults in more than 15 years. Tonix's CNS commercial infrastructure supports its marketed products, including its acute migraine products, Zembrace® Symtouch® (sumatriptan injection 3 mg) and Tosymra® (sumatriptan nasal spray 10 mg). Tonix is investigating TONMYA® in Phase 2 clinical trials to evaluate its potential in major depressive disorder and acute stress disorder/acute stress reaction. Tonix is also advancing a pipeline of immunology programs, including TNX-4800, a Phase 2 ready long-acting human anti-*Borrelia* OspA monoclonal antibody (mAb) for the prevention of Lyme disease in the U.S., and TNX-1500, a Phase 2 ready third-generation CD40 ligand inhibitor for the prevention of kidney transplant rejection. In addition, the Company is progressing TNX-2900 (intranasal potentiated oxytocin), which is Phase 2 ready for the treatment of Prader-Willi syndrome, a rare disease. To learn more, visit www.tonixpharma.com and follow the Company on LinkedIn and X.

*\*Tonix's product development candidates are investigational new drugs or biologics; their efficacy and safety have not been established and have not been approved for any indication.*

Zembrace SymTouch and Tosymra are registered trademarks of Tonix Medicines. TONMYA is a registered trademark of Tonix Pharma Limited. All other marks are property of their respective owners.

**Forward Looking Statements**

Certain statements in this press release are forward-looking within the meaning of the Private Securities Litigation Reform Act of 1995 including those relating to the completion of the offering, the satisfaction of customary closing conditions, the intended use of proceeds from the offering and other statements that are predictive in nature. These statements may be identified by the use of forward-looking words such as "anticipate," "believe," "forecast," "estimate," "expect," and "intend," among others. 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 in the Company's Annual Report on Form 10-K for the year ended December 31, 2025, as filed with 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.

**Investor Contacts**

Jessica Morris

Tonix Pharmaceuticals

investor.relations@tonixpharma.com

(862) 799-8599

Brian Korb

astr partners

(917) 653-5122

brian.korb@astrpartners.com

**Media Contacts**

Deborah Elson

Tonix Pharmaceuticals

deborah.elson@tonixpharmaceuticals.com

Ray Jordan

Putnam Insights

ray@putnaminsights.com

## Exhibit 99.02

[TONIX PHARMACEUTICALS HOLDING CORP. 8-K](tnxp_8k-042226.htm)

**Exhibit 99.02**

![](ex99-03_img1.jpg)

## Exhibit 99.03

[TONIX PHARMACEUTICALS HOLDING CORP. 8-K](tnxp_8k-042226.htm)

**Exhibit 99.03**

![](ex99-04_img1.jpg)