Cidara Therapeutics’ lead drug, rezafungin, now in Phase 3 development, is a broad-spectrum antifungal in a known class, the echinocandins, but the COVID-19 pandemic has moved the spotlight to the antiviral Fc-conjugate (AVC) drugs in the company’s novel antiviral platform that offer both prevention and treatment. Its AVCs are designed to attack viruses directly and also activate the immune system against them. In Cidara’s pipeline, the lead antiviral drug, coded CD377, targets influenza, but other potential targets are RSV (respiratory syncytial virus), HIV, and COVID-19.