Cidara Therapeutics Secures FDA Breakthrough Therapy Designation For Its CD388 Candidate Against Seasonal Flu

Cidara Therapeutics, Inc., a biotechnology company developing drug-Fc conjugate (DFC) therapeutics through its proprietary Cloudbreak® platform, has announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy designation for its investigational therapy CD388. The designation is for the prevention of influenza A and B in adults and adolescents at higher risk of influenza complications, including individuals with underlying immunodeficiency, those who remain at high risk despite vaccination, or people for whom vaccines are contraindicated.

Jeffrey Stein, Ph.D., President and Chief Executive Officer of Cidara, stated, “This Breakthrough Therapy designation, alongside the previously awarded Fast Track designation, highlights CD388’s potential as a new non-vaccine preventive option for seasonal influenza. People with chronic medical conditions, advanced age, or compromised immune systems may not receive full protection from existing vaccines and remain vulnerable to flu-related complications. As a long-acting prophylactic, CD388 does not rely on the body’s immune response, offering a potential solution for high-risk populations and individuals who cannot receive vaccines. We are eager to advance CD388 through our ongoing Phase 3 ANCHOR trial and eventual Biologic License Application submission.”

The Breakthrough Therapy designation follows positive results from the Phase 2b NAVIGATE trial, in which CD388 demonstrated statistically significant prevention of seasonal influenza in healthy, unvaccinated adults aged 18 to 64. Top-line results from the NAVIGATE study were announced in June 2025, with additional data scheduled to be presented at upcoming scientific conferences in October.

The Phase 3 ANCHOR trial, initiated at the end of September 2025, evaluates the safety and efficacy of CD388 in populations at high risk for influenza complications. Following FDA feedback, the study population has been expanded to include generally healthy adults over 65, in addition to individuals with specific comorbidities and immunocompromised status, ensuring a comprehensive assessment of CD388 across multiple high-risk groups.

Breakthrough Therapy designation is designed to accelerate the development and review of therapies for serious or life-threatening conditions that demonstrate preliminary evidence of substantial improvement over existing treatments. Benefits of the designation include eligibility for priority review, rolling submission of application components, and enhanced guidance from FDA senior management to help optimize the path toward approval. Cidara continues to advance CD388 as a promising new long-acting influenza prophylactic aimed at providing protection for vulnerable populations who may not be adequately served by current vaccines.