The drug plausibly blocks replication of the SARS-CoV-2 virus in human lung cells and monocytes (white blood cells).
The article also appeared in the New York Post and Jerusalem Post.
A Science Alert article says: "A paper came out in Nature on July 22 that further underscores earlier studies that show that neither the malaria drug hydroxychloroquine nor chloroquine prevents SARS-CoV-2 – the virus that causes COVID-19 – from replicating in lung cells."
Zinc was used with hydroxychloroquine in some cases, but the article doesn't mention zinc.
RLF-100 was used to treat critically ill patients, whereas earlier alleged successes with hydroxychloroquine were mainly with early-stage mildly infected patients or as prevention. The blocking versus not blocking replication of the virus is a big difference, too.
Update August 4
This page shows a transcript of Dr. Anthony Fauci testifying about hydroxychloroquine. He is acutely asked about using zinc with hydroxychloroquine, and he evades the question. (He refers to corticosteroids, which contain no zinc.) He clings to the "gold standard" despite its very long time frame and requiring giving very ill patients a placebo, and the urgency of finding a cure.