why are there no replicase inhibitors for coronavirus

[smolepi]

to the biochem/virology folks, if replicase is specific and critical to RNA virus, why hasn’t there been any replicase inhibitor for coronavirus like SARS and MERS?

asking for a friend

[Walfred]

There is definitely a possibility and potential to make one. However, why would pharmaceutical companies spend billions on something without no apparently return profit. 

[DRMF]

Remdesivir? https://www.nejm.org/doi/full/10.1056/NEJMoa2001191