San Diego-based Cidara Therapeutics reported highly favorable results from its randomized, double-blind, placebo-controlled Phase IIb Navigate trial, testing the long-acting antiviral biologic CD-388 for seasonal influenza prevention in healthy, unvaccinated adults aged 18 to 64. The study met its primary efficacy endpoint, demonstrating statistically significant protection against laboratory-confirmed influenza across multiple dosing groups over 24 weeks. Secondary endpoints showed maintained effectiveness up to 28 weeks and strong tolerability with no unexpected dose-limiting adverse events. Positive mid-stage results have prompted plans to meet with the FDA regarding Phase III trial design, potentially positioning CD-388 as an alternative to conventional seasonal vaccines and representing a multibillion-dollar market opportunity.