POZN got a good deal. They agreed to a minimum $5M annual royalty in 2014 (that will be greatly exceeded due to HZNP sales success to date), and that gets increase 50% in 2015 and all subsequent yrs barring generic.
So unless there is a perception that HZNP will walk away from V and it's contract entirely (for which there seems no basis), POZN is not at great risk here. Ultimately, it's PA, the prospects of which have not changed.
" Pozen will receive a 10% royalty on any of Vimovo's U.S. sales, or a minimum royalty payment of $5 million in 2014, and $7.5 million annually until generics reach the market."
Ex-US sales of Vimovo approached $100mm last year and POZN gets 6% of that, increasing to 10% in 2016. Granted, there's some uncertainty as to whether AZN will transfer its ex-US rights and, if it does, whether the new licensee will be better or worse, but that aside, US + foreign sales of Vimovo should still net POZN at least $15-20 million a year by 2016 even if HZNP's sales decline dramatically. That could be a nice little add-on to what PA, which I agree is what POZN is mostly about, will hopefully bring in.