The FDA has released some new guidelines intended to make it easier to get drugs into the earliest stages of human trials. Considering how often we fail at those stages of development, anything that increases our number of shots on goal is good news.
The first part of the new approach is a set of official standards for what are known as "Exploratory INDs". (An IND (Investigational New Drug) application is the mound of paperwork that you have bring to the FDA in order to dose human subjects). What they're doing here is making it easier to test limited numbers of people at smaller doses, just to see if you can narrow down your drug candidates with some realistic data. This "microdosing" approach has been tried in Europe for the last few years, and it's definitely time the the agency laid out the rules for its application over here.
I think that for the most part the key data obtained in these trials will be pharmacokinetics - you could take three or four roughly equivalent drug candidates in and see which one had the best blood levels and distribution before committing yourself. (Fancy mass spectrometry techniques can allow you to see very small amounts of compound or metabolites in samples these days). This approach will also work out well if you have some sort of clinical marker that you trust. Sub-effective doses of the drug candidates could still point you to which ones are having the effect you want, if the signal-to-noise ratio of your surrogate marker is good enough. Imaging studies would be another good use for these trials.
If I'm reading their guidelines right, the FDA can let you go into human microdosing with only rat data. That sounds either exciting or alarming, depending on your point of view, but given the low doses involved, I think it's a good thing. For dosing up to pharmacologically active levels, though, they want the traditional rat/dog safety package, which is certainly reasonable.
The second part of the new standards are for manufacturing drug substances for these early trials. What they're doing, it seems, is loosening up the "Current Good Manufacturing Practice" rules a bit for small exploratory studies. This is mostly going to help out the smaller companies and (especially) academia. CGMP is no fun to follow if you're not set up for it, and it is rather odd to make the five-gram-batch folks jump through almost the same hoops as the five-thousand-kilo people. For the larger companies with lots of CGMP capacity, though, I don't see this change making much of a difference.
It'll be interesting to see what sort of coverage this gets in the press - assuming it gets much at all, that is. There's room for a sufficiently motivated complainer to go on about the FDA loosening up on its regulation of unknown toxic drug substances, poisoning America, slippery slope, etc. If any readers spot someone taking this tack, forward the reference to me, and I'll reward you with a laudatory mention here. It'll look great on your CV. Trust me.