I missed last night's announcement from Bristol-Meyers Squibb until this morning. It looks like the situation with Pargluva (muraglitazar) is even worse than people had thought.
The FDA had granted "conditional approval" for the drug, but that doesn't mean all that much. The conditions for approval weren't made public, by either the agency or the companies involved - all we knew was that they wanted to address cardiovascular risk factors. Now BMS says that the ongoing trials won't be able to answer the FDA's concerns, and that new trials would be needed, which they say might take up to five years. That could scuttle the drug entirely.
I'm not sure what to make of this. It's entirely possible that BMS and Merck don't have anything currently powered to address cardiovascular risk in the way the the FDA would like. People complained that the Cleveland Clinic article in JAMA was based on incomplete data, but if there were good cardiovascular numbers on this drug, they would have been in that data set. But five years seems like a long time, even if the FDA is really lowering the boom on them and requiring long-term data in a large number of people. Even then, even factoring in recruitment and data workup, that's a whopper of a trial.
Still, I think the companies are clearly looking at more time and money than they probably want to spend, on a drug that frankly was a bit disappointing in its clinical data. Pargluva lowers blood glucose, but so do the existing PPAR-gamma agents. They already do about as much as can be done through that mechanism. And the additional PPAR-alpha activity does seem to help HDL cholesterol and other blood lipid parameters, but the cardiovascular risk that seems to be there more than offsets those numbers.
Merck and BMS run the risk of spending a very large amount of money just in order to definitively prove that their drug should not be sold. Even if they were able to make their case, it's unlikely that they'd be able to make a strong case in the market: "Pargluva! Not As Bad As You Thought!" And the market would have changed by the time they staggered on to approval, anyway. They may just give this one a pass.
It'll be interesting to see how this plays in the press. It'll be easy to fit this into a template of "FDA messes up, independent review by Cleveland Clinic saves the day again." But that's not quite true, I think. The FDA advisory committee didn't distinguish itself, and the Cleveland team was quick to pick up on that, but the agency itself requested the additional data before the JAMA article came out. I don't know what might have gone on behind the scenes, but on the face of it, this was one of the cases that proves (as the fine print says) that the FDA doesn't have to abide by the decisions of its advisory committees.