It could be annoying to have to monitor the QTc interval during treatment
It's my impression that many doctors don't pay much attention to QTc issues at all, at least with drugs they are already familiar with (like Zithromax). It's partly the FDA crying wolf on this with drugs that in actual practice don't appear to cause any problems at all.
On the other hand, I could see the FDA being very cautious indeed on this drug, with the shadow of Vioxx hanging over it. It's going to be used on top of NSAIDS, which appear to have some modest cardiac risk to begin with, and so I would expect the FDA to require a significant sized cardiac outcomes study. So that's something that could only be done by a partner while at the same time being a deterrent to any would-be partner.
I am impressed they showed an effect on top of NSAIDs - I kind of assumed that the NSAIDs partly worked by inhibiting the p38 pathway, but seems things must be more complex than that.