The results are certainly credible - they are qualified investigators, there are no commercial pressures (generic low cost drugs), and there is cell culture evidence that chloroquine kills the virus.  However, the weaknesses in the data are (a) small numbers, (b) open label uncontrolled trial. 

So we need to be cautious and not get too excited, but it certainly warrants doing a larger controlled trial. I imagine this will not take more than a few weeks.

So let's hope.