[toast0]

The problem is, if something related to how you run your test of the anti-fungal has an effect on the disease, you're going to assume its the anti-fungal; but maybe it's not. If you have a control group, and both groups do better than expected (compared to the body of evidence), then you've learned something you wouldn't have without a control group (and you'll have to work hard to figure out what changed in this study vs other studies). If anti-fungals are a clear winner, it's likely that the study protocol would be changed to give everyone the drug after early results.