From what I can gather chloroquine is already used as a first line treatment in Italian hospitals (at least it is indicated as such by the COVID treatment guidelines published by the society of Italian infectious disease specialists [0], and has been for quite some time - this document is from 10 days ago, but an earlier revision was not different regarding chloroquine). If this is the case, it's pretty clear that this is no miracle cure - it has at best a marginal effect.
[0] http://www.simit.org/medias/1569-covid19-vademecum-13-03-202...