New Protocol Advances Valion Bio's Radiation Treatment

Valion Bio's drug Entolimod is moving closer to becoming the first FDA-approved treatment for a lethal form of radiation sickness, following a new testing protocol finalized by federal defense and health agencies. The advancement addresses a critical gap in America's emergency preparedness and national security stockpile.

Addressing a Critical Gap in Emergency Preparedness

Currently, the United States has no FDA-approved medical countermeasures for Gastrointestinal Acute Radiation Syndrome, known as GI-ARS. This condition is entirely lethal, remains untreated, and represents a massive vulnerability in the nation's biodefense strategy. Valion Bio, trading under the ticker VBIO on Nasdaq, is working to change that with its lead drug candidate, Entolimod.

The Armed Forces Radiobiology Research Institute, a division of the U.S. Department of War, partnered with the National Institute of Allergy and Infectious Diseases to finalize the survival efficacy protocol for Entolimod. This move directly follows the U.S. House Armed Services Committee's direction to the Department of War. The committee mandated that the department prioritize radiation countermeasures that work both before and after exposure, a key requirement for protecting military personnel and civilians during a nuclear event.

This push for accountability ensures that the government actively fields the resources necessary to protect American lives, rather than leaving the country defenseless against nuclear threats.

How the FDA Animal Rule Paves the Way for Approval

Because testing a radiation drug on humans is unethical and impossible, the FDA uses the Animal Rule. This regulatory pathway allows the agency to approve new drugs based on high-quality animal efficacy studies when human clinical trials are not feasible.

The newly designed protocol uses a specific animal model known as PBI-BM2.5. This model exposes the subjects to a lethal dose of radiation while shielding exactly 2.5% of their bone marrow. By doing this, researchers can isolate the gastrointestinal damage from other failing systems in the body. This creates a much clearer picture of how well Entolimod repairs intestinal tissue and restores immune function.

Entolimod works by selectively activating a specific immune receptor called TLR5. This triggers pathways that protect cells from damage and stop cell death in tissues highly sensitive to radiation. It offers a distinct advantage over current treatments that only target the blood, leaving the gastrointestinal tract to fail.

Strong Market Potential for Biodefense

The advancement of Entolimod comes as the global market for acute radiation syndrome countermeasures accelerates. Market valuations reached an estimated $5.47 billion in 2025 and are projected to hit $7.80 billion by 2032. North America accounts for 46% of this revenue, driven heavily by government stockpiling and biodefense spending.

Valion Bio CEO Michael Handley highlighted the importance of this milestone for both the company and national security.

The AFRRI protocol finalization represents a key inflection point for Entolimod as a radiation countermeasure and for Valion as a company. We are now positioned to generate the high-quality non-clinical efficacy data that the FDA and the government require to support future licensure under the Animal Rule. The gastrointestinal subsyndrome of ARS is the market's greatest unmet need. It is lethal, it is currently untreated, and it is precisely where Entolimod's mechanism has the greatest potential to differentiate from incumbent therapy.

What This Means for Valion Bio and Domestic Manufacturing

Valion Bio, formerly known as Tivic Health Systems, focuses on developing biologics that activate innate immune pathways. Beyond Entolimod, the company is advancing Entolasta, a next-generation therapy designed for broader applications, including oncology supportive care.

The company also operates Velocity Bioworks, a wholly owned contract development and manufacturing organization. Velocity Bioworks currently provides biomanufacturing services to Valion and is working toward offering services to third-party biotech companies. This domestic manufacturing capability is critical for securing the supply chain for vital medical countermeasures, ensuring America does not rely on foreign nations for life-saving drugs during an emergency.

With the protocol finalized, Valion Bio can now generate the data required for FDA licensure, bringing the United States one step closer to having a viable treatment for severe radiation exposure.

What is Gastrointestinal Acute Radiation Syndrome?

GI-ARS is a lethal condition caused by high levels of radiation exposure that severely damages the gastrointestinal tract. Currently, no FDA-approved treatments exist for this specific syndrome, making it a critical vulnerability in national emergency preparedness.

Why is the FDA using an animal model to test Entolimod?

The FDA uses the Animal Rule because exposing human subjects to lethal doses of radiation for clinical trials is unethical and unfeasible. The agency can approve drugs based on animal data when human trials are impossible, provided the animal model is scientifically rigorous.

What government agencies are involved in testing Entolimod?

The Armed Forces Radiobiology Research Institute, part of the U.S. Department of War, and the National Institute of Allergy and Infectious Diseases partnered to design the testing protocol for Valion Bio's drug. The U.S. House Armed Services Committee also directed the Department of War to prioritize these countermeasures.