Cidara Therapeutics reported positive mid-stage data for CD388, a drug-Fc conjugate antiviral providing season-long prophylaxis against influenza A and B viruses. Phase 2b results showed that a single high dose was 76% effective in preventing flu symptoms over 24 weeks, with good tolerability and no unexpected adverse events. The company plans to engage with the FDA for Phase 3 trial design, positioning the therapy as a potential alternative to annual vaccines. The promising data caused a doubling of Cidara’s stock value. This development highlights innovative antiviral approaches targeting unmet needs in respiratory virus prophylaxis.