Friday, October 17, 2008

Big Tent for Stent Trial Is All About Predictability of Results

Eight large product companies--including the top four drug-eluting stent (DES) companies, Abbott, Cordis, Boston Scientific, and Medtronic, as well as drug companies Bristol-Myers Squibb and Sanofi Aventis, makers and co-marketers of current anti-platelet blockbuster Plavix, as well as Eli Lilly and Daiichi Sankyo, co-developers of the much anticipated prasugrel—are collaborating on a large-scale, $100 million clinical trial assessing late-stent thrombosis.

That's interesting, we suppose, but hardly surprising and not likely to lead to any remarkable findings. Rather, it is the very predictability of the study’s likely results that is, we’d bet, what’s brought everyone to the table.

For one thing, the role of anti-platelet therapy following DES implantation has been aggressively studied for years and got a boost when the whole late stent thrombosis (LST) debate took off a couple of years ago. And every study, including several presented at this year’s TCT meeting in Washington DC where the news of the launch of the new study was announced, has shown the same thing: yes, patients face a much lower risk of LST when they stay on their meds for some period of time.

The new study may determine what the optimal Rx regimen is, but the notion that patients need to follow that regimen is what everyone’s betting will come out of the new study—and it’s hardly news. Only the direct opposite—that staying on an anti-platelet therapy has no impact on LST—would register as anything like a surprising result.

Moreover, what the WSJ called “an unusual display of collaboration,” among the companies—unusual, presumably, because they’re all fierce rivals in this space--is also hardly that. There’s no competitive issue at all here. All eight of the product companies are hoping and betting that the study results prove the clinical value of aggressive anti-platelet therapy—the drug companies, because they want to sell more drugs, the stent companies because they would like to show, once and for all, that the LST problem is more about the use of drugs than the use of stents and, more importantly, that the problem of LST is treatable with drugs.

Indeed, this could be an important study for both the Pharma and Device companies, but more so for the latter, if it conclusively demonstrates that physicians need not be concerned about putting their patients at risk by implanting a DES—if it proves to be the kind of large, definitive study that everyone called for when the LST crisis first broke.

But unless the study shows that one or two of the four stents being studied have substantially lower LST rates when the patient follows the appropriate drug regimen, there won’t be much of a competitive impact—this will be the rising tide that lifts all boats. And again, just based on earlier studies—LST has also been much studied in DES trials, particularly in the last two years—while head-to-head comparisons of various DES have shown different rates of stent thrombosis, they haven’t been meaningful.

In fact, if anything, the study’s risk, especially to DES companies, may lie not in findings that would show one stent superior to another, but just the opposite: findings that basically confirm everything we already know. The LST scare that burst onto the scene two years ago following data reported by Swedish researchers based on a Swedish patient registry was the device industry’s equivalent of Vioxx: a safety concern that caused havoc with what was once believed to be a blockbuster product category.

Drug-eluting stents are still the device industry’s one true blockbuster product. But the market has contracted—from $6 billion and growing a couple of years ago to $5 billion and stagnant—and reports from this year’s TCT suggest that while DES use has rebounded, that rebound has been mighty small.

The LST debate has been the leading cause of the contracted market. (Improvements in bare metal stents have also cut into DES sales, but only because of their implications in the LST debate.)

$100 million isn’t much spread among 8 companies, but only if, as stent companies hope, this kind of large, high-profile study conducted by a prestigious research organization, finally puts to rest the LST debate. If it doesn’t, if it simply raises calls for more studies looking at similar data—which is what’s happening a lot lately in cardiovascular circles—it could be a problem. --David Cassak

image of Taxus stent courtesy FDA via wikimedia commons.

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