VALION BIO BRIEFS PENTAGON LEADERSHIP ON ENTOLIMOD™ FOR ACUTE RADIATION SYNDROME

Company Presented Entolimod™ from its TLR5 Platform to the Deputy Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs

SAN ANTONIO, April 28, 2026 /PRNewswire/ -- Valion Bio, Inc. (formerly Tivic Health Systems, Inc.) (Nasdaq: VBIO), a late-stage immunotherapeutics company, today announced that it briefed senior officials at the U.S. Department of War on Entolimod™ for acute radiation syndrome. The briefing, facilitated by American Defense International (ADI), was presented to the Deputy Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs and his team at the Pentagon.

The briefing reflects growing U.S. government interest in Entolimod™ as a next-generation medical countermeasure for radiological threats. Entolimod™ is a novel Toll-like receptor 5 (TLR5) agonist that provides dual-tissue protection against ionizing radiation-induced damage, addressing both hematopoietic and gastrointestinal acute radiation syndrome — a differentiated mechanism not available in currently stockpiled countermeasures.

"Engaging directly with senior leadership at the Pentagon marks a significant milestone in our work with the Department of War," said Michael K. Handley, Chief Executive Officer of Valion Bio. "The Deputy Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs oversees critical national preparedness capabilities, and the opportunity to present Entolimod™ at this level validates our strategic positioning at the intersection of biodefense and medical countermeasures. We were able to demonstrate the strength of our data package and how Entolimod™ addresses current gaps in the Strategic National Stockpile."

Entolimod™ is being developed under the FDA's Animal Rule pathway for acute radiation syndrome, with over $140 million invested in the program to date, including approximately $35.6 million in non-dilutive U.S. government funding. The compound has been evaluated in 42 non-human primate studies and administered to approximately 300 human subjects, demonstrating a well-characterized safety and efficacy profile.

Unlike currently stockpiled agents such as Neupogen® (filgrastim), Neulasta® (pegfilgrastim), and Leukine® (sargramostim), which target hematopoietic recovery alone, Entolimod™ activates NF-κB signaling pathways to protect both bone marrow and gastrointestinal tissues simultaneously. This dual-organ mechanism addresses a critical unmet need, as gastrointestinal damage is often the limiting factor for survival at higher radiation doses.

"The current geopolitical environment has elevated radiological preparedness to a national security priority," Handley continued. "Our engagements with BARDA, DTRA, NIAID, and now direct Pentagon leadership demonstrate that Entolimod™ is being recognized at the highest levels of the U.S. defense establishment as a differentiated solution to protect both military personnel and civilian populations. We are committed to moving with the urgency this threat environment demands."

The Pentagon briefing follows Valion Bio's recent selection for the Department of War's Tech Watch program and ongoing engagements with multiple U.S. government agencies regarding the inclusion of Entolimod™ in national preparedness planning. The Company has received FDA Fast Track and Orphan Drug designations for Entolimod™ in acute radiation syndrome and is advancing toward a Biologics License Application under the Animal Rule.

Strategic and Competitive Positioning

• National preparedness relevance: Dual GI and bone marrow protection addresses critical gaps in current stockpiled countermeasures
• Differentiated mechanism: TLR5 agonist provides pleiotropic cytoprotection versus single-target G-CSF therapies
• Regulatory pathway: Animal Rule framework reduces clinical development risk for biodefense applications
• Government validation: $35.6 million in prior federal contracts and ongoing multi-agency engagement

About Entolimod™ for Acute Radiation Syndrome

Entolimod™ (CBLB502) is a recombinant deletion variant of Salmonella FliC flagellin engineered to activate TLR5 selectively. Upon engagement, Entolimod™ triggers NF-κB-dependent signaling to stimulate G-CSF, PI3K, and IL-6 production, promote multi-tissue cytoprotection, and inhibit apoptosis in radiosensitive hematopoietic and gastrointestinal tissues. The compound has demonstrated survival benefit as both a radioprotectant and a radiomitigant in controlled non-human primate studies under the FDA's Animal Rule.

About Valion Bio, Inc.

Valion Bio, Inc. (Nasdaq: VBIO), the new corporate identity of Tivic Health Systems, Inc., is developing biologics that activate innate immune pathways for cytoprotection and modulate immune responses in conditions driven by radiation, disease, and immune dysregulation. The Company's lead candidate, Entolimod™ for acute radiation syndrome (ARS), has been extensively studied and has demonstrated survival benefits and improved tissue recovery in animal models under the FDA's Animal Rule. Entolimod™ is a novel Toll-like receptor 5 (TLR5) agonist that activates NF-κB signaling pathways to protect cells from damage and stimulate immune responses. Entolimod™ for ARS has received Fast Track and Orphan Drug designations from the U.S. Food and Drug Administration. Valion Bio is also advancing Entolasta™, a next-generation TLR5 agonist designed for potential broader therapeutic applications, including oncology supportive care. Valion Bio's wholly owned subsidiary, Velocity Bioworks, is a full-service contract development and manufacturing organization (CDMO) that provides biomanufacturing services to third-party biotech companies. Valion Bio also leverages Velocity Bioworks' manufacturing capabilities to advance its own drug pipeline with the expected benefits of lower costs, accelerated manufacturing outcomes, and supply chain security. For more information, visit www.valionbio.com.

Forward-Looking Statements

This press release may contain "forward-looking statements" that are subject to substantial risks and uncertainties. All statements, other than statements of historical fact, contained in this press release are forward-looking statements. Forward-looking statements contained in this press release may be identified by the use of words such as "anticipate," "believe," "contemplate," "could," "estimate," "expect," "intend," "seek," "may," "might," "plan," "potential," "predict," "project," "target," "aim, "should," "will," "would," or the negative of these words or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements are based on Valion Bio, Inc.'s current expectations and are subject to inherent uncertainties, risks, and assumptions that are difficult to predict. Further, certain forward-looking statements are based on assumptions as to future events that may not prove to be accurate, including as a result of the company's interactions with and guidance from the FDA and other regulatory authorities; the continued interest of BARDA and other U.S. government agencies in Entolimod™; the ability of the company to achieve the expected benefits from the acquisition of development and manufacturing assets within expected time frames or at all; changes to the company's relationship with its partners; failure to obtain FDA or similar clearances or approvals and noncompliance with FDA or similar regulations, including related to the Animal Rule; the company's future development of Entolimod or Entolasta; changes to the company's business strategy; timing and success of pre-clinical and clinical trials and study results; regulatory requirements and pathways for approval; the company's ability to successfully commercialize its product candidates in the future; changes in the markets and industries in which the company does business; consummation of any strategic transactions; the company's need for, and ability to secure when needed, additional working capital; the company's ability to maintain its Nasdaq listing; and changes in tariffs, inflation, legal, regulatory, political and economic risks. Accordingly, you are cautioned not to place undue reliance on such forward-looking statements. For a discussion of risks and uncertainties relevant to the company, and other important factors, see Valion Bio's filings with the SEC, including its Annual Report on Form 10-K for the year ended December 31, 2025, filed with the SEC on March 30, 2026, under the heading "Risk Factors", as well as the company's subsequent filings with the SEC. Forward-looking statements contained in this press release are made as of this date, and the company undertakes no duty to update such information except as required by applicable law.

Investor Contact:
Rich Cockrell
CG Capital
[email protected]

SOURCE Valion Bio, Inc.