Very small study, but French say arthritis drug
Anakinra
had rapid positive effect on severe Covid-19 patients

https://medicalxpress.com/news/2020-07-rheumatoid-arthritis-drug-severe-covid-.html

Sample quote

A team led by Dr. Gilles Kaplanski, of the Public Assistance Hospital in Marseille, reported that in a study involving 22 very ill patients,
“all of the patients treated with anakinra improved clinically with no deaths, significant decreases in oxygen requirements, and more days without invasive mechanical ventilation."

The drug also seemed to have a "rapid" effect,
with fever receding at an average of three days after the first intravenous infusion was given,
the researchers reported July 22 in the Proceedings of the National Academy of Sciences.

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