Long-acting Antiviral for Pre-exposure Protection Against Influenza Launches Phase 2b Study

Cidara Therapeutics, Inc., today announced the first subjects dosed in the Phase 2b NAVIGATE trial in the U.S. and U.K. The trial evaluates the efficacy and safety of CD388, a long-acting antiviral, for the pre-exposure prophylaxis of influenza during the 2024-2025 flu season.

CD388 is an investigational drug-Fc conjugate (DFC) comprised of multiple copies of a potent small molecule neuraminidase inhibitor stably conjugated to a proprietary Fc fragment of a human antibody.

DFCs are not vaccines or monoclonal antibodies but low-molecular-weight biologics designed to function as long-acting small-molecule inhibitors. 

In a June 2024 bioRxiv manuscript, CD388 demonstrated potent, universal activity across influenza A and B viruses, including high pathogenicity and neuraminidase-resistant strains, a low potential for resistance development, and robust efficacy in lethal mouse infection models.

“Effective new options are needed to prevent influenza, particularly for people who do not respond well to seasonal flu vaccines,” said Jeffrey Stein, Ph.D., president and chief executive officer of Cidara Therapeutics, in a press release on September 23, 2024.

“Since CD388 is not a vaccine, its activity does not rely upon an immune response and is, thereby, expected to work regardless of immune status."

"In addition, CD388 has demonstrated the potential to prevent infection by both seasonal and pandemic strains of influenza A and B."

The Phase 2b clinical trial is a randomized, double-blind, controlled trial targeting 5,000 healthy, unvaccinated adult subjects who are not at risk of complications from influenza. Three CD388 dose groups or a placebo will be administered to subjects as a single dose at the beginning of the influenza season. Subjects will then be followed for the remainder of the influenza season to monitor for breakthrough cases.

Cidara Therapeutics is a biotechnology company using its proprietary Cloudbreak® platform to develop DFC immunotherapies designed to save lives and improve the standard of care for patients facing serious diseases.