Yes in vitro studies have shown a mechanism of action which should prevent covid from replicating. But this mechanism has not been borne out by in vivo trials. The potential has been shown to be dubious at best. Meanwhile other treatments are showing real results including remdesivir and human antibody or recuperative plasma.
I posted a like up near the top of this discussion which details how these work, including a graphic explainer of how HCQ could work.
