San Antonio, Texas, March 26, 2026
In a strategic move to address critical gaps in radiation emergency therapeutics, Tivic Health Systems has secured a non-clinical evaluation agreement with the National Institute of Allergy and Infectious Diseases (NIAID) to advance its lead candidate Entolimod™ for the treatment of gastrointestinal acute radiation syndrome (GI-ARS). This collaboration represents a major step in the development of medical countermeasures for radiation exposure, particularly in scenarios involving nuclear accidents or radiological threats. The agreement enables government-funded preclinical studies, accelerating Tivic’s pathway toward regulatory approval while significantly reducing development costs.
Targeting a Critical Gap in Radiation Treatment
Acute radiation syndrome (ARS) remains a serious public health concern, especially in high-dose exposure events where gastrointestinal damage is a leading cause of mortality. While currently approved therapies such as granulocyte colony-stimulating factors focus on restoring the hematopoietic system, they do not directly address GI tract injury, leaving a substantial unmet need in patient care.
Tivic’s Entolimod is being developed specifically to protect gastrointestinal tissues from radiation-induced damage, including mucosal necrosis, which is a key driver of fatal outcomes in severe ARS cases. The preclinical program will initially utilize mouse models, with potential progression to non-human primate studies if efficacy is demonstrated, aligning with regulatory requirements under the FDA’s Animal Rule..
Innovative Mechanism and Scientific Potential
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Entolimod is a Toll-like receptor 5 (TLR5) agonist that activates NF-κB signaling pathways, triggering innate immune responses that help protect cells and tissues from radiation damage. This unique mechanism of action differentiates it from existing therapies by offering multi-tissue cytoprotection, including the gastrointestinal system, which is often overlooked in current treatment approaches.
Preclinical evidence suggests that Entolimod may enhance survival rates and promote tissue recovery, positioning it as a next-generation therapeutic candidate in the radiation medicine space. The ability to activate innate immunity also opens potential applications beyond ARS, including oncology supportive care and immune modulation therapies, strengthening Tivic’s broader pipeline strategy
Regulatory Pathway and Strategic Advantages
A key advantage of this collaboration is that NIAID will fully fund and conduct the studies, providing Tivic access to advanced research infrastructure without additional capital burden. The studies will be carried out at the Armed Forces Radiobiology Research Institute (AFRRI), a leading center for radiation research, ensuring high-quality data generation. Importantly, the program is designed to support regulatory approval under the FDA Animal Rule, a pathway used when human efficacy trials are not feasible or ethical.
This positions Entolimod for a potential expedited Biologics License Application (BLA) submission, accelerating its availability as a critical biodefense medical countermeasure. Additionally, Entolimod has already received Fast Track and Orphan Drug designations, further strengthening its regulatory outlook and market potential.
The collaboration highlights a growing emphasis on public-private partnerships in biopharmaceutical innovation, particularly in areas of national security and emergency preparedness. By addressing gastrointestinal complications of radiation exposure, Tivic aims to fill a longstanding therapeutic gap and improve survival outcomes in high-risk scenarios.
As global awareness of radiological threats increases, the development of effective and scalable ARS treatments becomes increasingly critical. With non-dilutive funding, a differentiated mechanism, and a clear regulatory pathway, Entolimod stands out as a promising candidate in the evolving landscape of radiation countermeasure development.
Source: Tivic Health press release
