GC376 is a broad-spectrum antiviral medication under development by the biopharmaceutical company Anivive Lifesciences for therapeutic uses in humans and animals. Anivive licensed the exclusive worldwide patent rights to GC376 from Kansas State University. As of 2020, GC376 is being investigated as treatment for COVID-19. GC376 shows activity against many human and animal viruses including coronavirus and norovirus; the most extensive research has been multiple in vivo studies in cats treating a coronavirus which causes deadly feline infectious peritonitis. Other research supports use in porcine epidemic diarrhea virus.
Mechanism of action
GC376 is a 3C (3C-Like) protease inhibitor. Protease is an enzyme that is a key catalyst for proteolysis - the cleavage of peptide bonds of viral polyproteins, as well as for the assembly of parts of the virus into a functional unit and the "maturation" of the virus. GC376 blocks the activity of the protease, thereby interrupting the life cycle of the virus, which can no longer replicate.
Preparation of injection solution with GC376
GC376 is dissolved for injection use in a solution consisting of 10% ethanol and 90% PEG-400.
Field trial study and commercialization
In September 2017, a field trial study entitled Efficacy of a 3C-like protease inhibitor in treating various forms of acquired feline infectious peritonitis, whose main authors are Dr. Niels Pedersen and Yunjeong Kim. This study clearly demonstrated the efficacy of GC376 in the treatment of FIP. The company which is trying to approve the medicine and place it on the market is Anivive. The launch could take place sometime around 2023.
GC376 is currently a bit forgotten, as GS441524 is mainly used to treat FIP. However, GC376 still appears to be justified, for example, in a situation where resistance to GS441524 develops. In addition, it is possible that future drugs for FIP will contain both active ingredients GS441524 and GC376, as they complement each other, which may lead to their synergistic therapeutic effect.