I just heard that the Pagoclone study will start in March at several center across the US. This info fits the press release from last year: .
So we should not expect any results until March next year earliest. Six months treatment period plus at least 3 months logistics (i.e. not everyone will be enrolled on same day) plus 3 months analysis time, and maybe a few months of observation time.
Here is my prediction: If they are good scientists, they will get a null or minor impact result above placebo and repeated measurement effect. If they are bad scientists, they will get a moderate result good enough to market the compound for stuttering. However, they might be able to show that it has a good impact in some people, but they then must convince me that this is not a random effect.