Excellent points, stealthways, which I hadn't fully considered. I'm sure you've seen the outstanding post on epilepsy today by dadofmarcmax on YMB, but if not, that is definitely essential reading.
Something I've often wondered was whether or not the metabolite of ANAVEX 2-73 (aka ANAVEX 19-144) would need its own phase 1. The A2-73 phase 1 measured the pharmacokinetics of both A2-73 and its metabolite A19-144, but only after oral administration of parent A2-73.
This is relevant to the antiepilepsy indication because only one of the formulations cited in the preclinical abstract was with parent ANAVEX 2-73 (A2-73 + ethosuximide). The other two were combinations involving metabolite ANAVEX 19-144.
I imagine they'll run a phase 2 trial with ANAVEX 2-73 alone and perhaps in combination with ethosuximide, but I'm not sure that they can go straight to phase 2 with ANAVEX 19-144 in combination with vaporic acid or gabapentin.
It is interesting to note that gabapentin's antiepilepsy indication is marketed by Pfizer as Neurontin, which was once a $3B drug. What other former multi billion dollar drug does Pfizer market? Oh, yeah: Aricept (donepezil). Hmmm...