Cidara’s CD388 Receives FDA Breakthrough Therapy Designation for Flu Prevention in High-Risk

Cidara Therapeutics has announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy designation to its investigational drug CD388 for the prevention of influenza A and B in individuals at heightened risk of severe flu complications. This includes adults and adolescents with immunodeficiency, those unlikely to benefit from current vaccines, and patients for whom vaccines are not an option.

CD388, developed using Cidara’s proprietary Cloudbreak® drug-Fc conjugate (DFC) platform, is a long-acting, non-vaccine prophylactic designed to protect against seasonal influenza without relying on the patient’s immune response. This makes it a promising option for immunocompromised individuals and others who are not adequately protected by standard flu vaccines.

“This Breakthrough Therapy designation, in addition to Fast Track status already granted, highlights the potential of CD388 to fill a critical gap in flu prevention,” said Dr. Jeffrey Stein, President and CEO of Cidara. “We are especially encouraged by its promise as a preventative therapy for those at greatest risk of influenza-related complications.”

The designation follows positive results from the Phase 2b NAVIGATE trial, which demonstrated that CD388 significantly reduced the incidence of seasonal influenza in healthy, unvaccinated adults aged 18–64. Full results from that study will be presented later this month at scientific meetings.

Cidara has already initiated the Phase 3 ANCHOR trial, six months ahead of schedule, to further evaluate the safety and efficacy of CD388 in high-risk groups. Following feedback from the FDA, the trial has been expanded to include generally healthy individuals over 65 years of age, in addition to immunocompromised populations and those with comorbidities.

Breakthrough Therapy designation is intended to expedite the development and review of drugs that treat serious or life-threatening conditions and show early signs of clinical benefit over existing therapies. It offers benefits such as priority review, rolling submissions, and close guidance from senior FDA officials throughout the approval process.

CD388 represents a potential game-changing approach to influenza prevention for those most vulnerable to the virus, as Cidara advances toward a Biologic License Application submission.