Migraine presents a unique issue—the injection protocol for on-label Botox treatment (31 distinct injection sites) is patented by ABBV. If RVNC decides to pursue migraine, it will need to either license ABBV’s patent or devise a new injection protocol—almost certainly the latter because devising an alternative injection protocol should be pretty straightforward.
So, you’re correct that RVNC’s pursuing migraine would require one or more phase-2 trials before advancing to phase-3.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”