Well, that’s where the heterogeneity of migraine comes into play. What constitutes insufficient efficacy for some people may be sufficient for others. Migraine is a large enough market that there’s room for drugs with multiple MoAs to garner meaningful sales.
Where I tend to agree with you is on the technical difficulty—and cost—of running two successful phase-3 trials, and this is why I’d prefer that RVNC leave this indication alone and simply take whatever off-label sales they can muster.
There is some argument that Botox…works via decreasing CGRP, and if that is correct I'm not sure there will be patients that fail a CGRP and work with a Botox-type drug.
Due to its lower cost relative to CGRPs, botulinum toxin will likely continue to be a first-line option for most patients who use it, so the presumed lack of efficacy in the second-line setting won’t matter much from a business standpoint.