Clinicaltrials.gov, the most commonly used registry for worldwide medical research, listed 1358 clinical trials on the [COVID-19], including using scores of different potential drugs and multiple combinations, when I first wrote this sentence. The following day that number of trials had increased to 1409. Laboratory work to prepare for trials presents an even broader and untabulated scope of activity.
Most trials will fail or not be as good as what has been discovered in the interim, but the hope is that a handful of them will yield vaccines for prevention and treatments to attenuate and ultimately cure the deadly infection.
The first impulse is to grab whatever drugs are on the shelf and see if any work against the new foe. We know their safety profiles and they have passed some regulatory hurdles. Remdesivir is the first to register some success against SARS-CoV-2, the virus behind the disease. The FDA has granted it expedited-use status, pending presentation of data that may lead to full approval of the drug.
Laboratory work suggests that other drugs, both off-the-shelf and in development, particularly those to treat HIV and hepatitis, might also be of some benefit against SARS-CoV-2. But the number of possible drug combinations is mind-bogglingly large and the capacity to test them all right now is limited.