Cayman Chemical recently released an article on the first FDA-approved COVID-19 treatment. This is not be confused with the first approved COVID-19 vaccine in the UK (produced by Pfizer). Treatments aid in the maintenance of disease symptoms by relieving or eliminating them, whereas vaccines prevent the onset of the disease. The metabolic breakdown of remdesivir is being studied to explain how it reduces symptom severity of COVID-19. Essentially, remdesivir diffuses into cells where it is metabolized into an alanine intermediate, and then metabolized into a nucleoside monophosphate. Subsequently, it is either converted into a nucleoside analog or phosphorylated to form an active nucleotide triphosphate (i.e., the active building blocks of RNA and DNA). As such, it can then be incorporated into the viral genome by RNA-dependent RNA polymerase (RdRp) during viral replication and disrupt this process (Figure 1). While promising the clinical results on which this treatment was approved are minimal.
Figure 1. Diagram showing remdesivir metabolism.
In one study (cited by the FDA in its approval of remdesivir), there were statistically significant shorter hospital stays for COVID-19 patients with lower respiratory tract infection and/or pneumonia when treated with a five-day course of remdesivir. However, this same study showed no statistically significant change between standard care and a ten-day course of remdesivir. These results urge additional research and review of the mechanism of action for remdesivir metabolism.
To view the full article, and its chemical rate of reaction as it is currently understood, click here.