Hydroxychloroquine (sometimes with an antibiotic) or HCQ. Chloroquine is also discussed but apparently it's a bit harsher of a medicine. But both have already have notable success in France, Germany, Italy, and I think even Australia. Some USA doctors are already using it (it's allowed by the FDA).
And honestly even if it works only 50% of the time, that's significant in curtailing the disease and winning the battle.