Monday, October 27, 2008

Wacky World of Generics: Treximet Edition

That was fast! Just six months after (finally) winning approval for its first product, Pozen announced that an application for a generic version of the sumatriptin/naproxen migraine combo (Treximet) has been filed at FDA.

Par Pharmaceuticals filed the generic application and notified Pozen and its partner GSK (now the NDA holder for the drug) that it is challenging the patents on Treximet and seeking to market a generic version as soon as Treximet’s data exclusivity expires. Under US law, Pozen is guaranteed three years of exclusivity on Treximet, and it expects an additional six months of exclusivity to be awarded once pediatric studies are complete.

So the earliest Par’s generic could launch is October 2011.

That doesn’t seem so far away—especially since the Treximet application was first filed at FDA in August 2005 and not approved until April 2008. In other words, the commercial lifespan of Pozen’s first product could end up being only 10 months longer than the review of the application by FDA.

We have written before about the regulatory and reimbursement challenges facing new formulations like Treximet. (For an update on another case study in that area, see Nitromed’s recent sale of Bidil to JHP Pharmaceuticals. Or, for that matter, look at what else Pozen had to talk about on the conference call: a potential change in the proposed endpoint for a new NSAID formulation partnered with AstraZeneca.)

Add another item to the list of why these seemingly “low-risk” R&D projects are anything but: the relatively short commercial lifespans for those products lucky enough to make it to market and secure reasonable payment.

Now, this isn’t exactly news: everyone knows the ground rules for exclusivity for new formulations. As Pozen CEO John Plachetka told investors on an Oct. 17 conference call, “we expected such an action by one or more generic companies” and “we have a plan in place to deal with this.”

The first step in that plan, no doubt, will be a lawsuit to enforce the patents. In theory, should Pozen and GSK prevail, they would be protected from generic competition as late as 2025. But if history is any guide, patents on new formulation or drug delivery technology generally have not been broad enough to block generics from designing around them, sooner or later.

Regardless, it sure seems awfully early to be talking about the end of Treximet’s exclusivity, since the product is barely even getting started in the marketplace.

Plachetka noted that unbranded direct-to-consumer ads only began to air around Labor Day, and September script data show strong growth. Branded DTC ads are now starting in some markets he added, so “we expect the trend to continue to get better as the DTC starts to hit.”

Even there, Pozen is paying the price for the changes in the regulatory climate. GlaxoSmithKline says it took three months for FDA to review its proposed DTC ads for Treximet. “We just lost some time in terms of FDA giving us approval,” GSK CEO Andrew Witty said during an investor call Oct. 22. “We now have all of that. We've got very good reaction in the marketplace, and I'm not worried about Treximet.”

Though pre-review by FDA is voluntary, in the current climate it is really more of a necessity. (We explain here why pre-review is the smartest thing a company can do with its DTC—except perhaps not run TV ads at all.) For FDA, though, Congress has sent a clear message: pre-reviewing ads is nice, but they want to see more enforcement. And, as “The Pink Sheet” reports here, that is precisely what Congress is getting. So sponsors shouldn’t expect speedy reviews of those DTC campaigns for the foreseeable future.

All of which begs the question: what, exactly, will GSK really get from Treximet?

The product is supposed to extend the lifecycle of the Imitrex franchise, facing its own patent cliff early next year (February 2009). That gives GSK less than one year to establish Treximet in the marketplace—and then the possibility that it loses the product just over two years later.

Treximet may be a highly effective migraine treatment, but it sure seems fair to ask whether it is worth the headaches for GSK…

1 comment:

Anonymous said...

So your point about "formulation" or "drug delivery" patents being of low value is inaccurate. See, for example, OxyContin, where Purdue's patents were thoroughly litigated and eventually upheld. Another example: Duragesic, where Alza held off the challenge from Mylan.

The real issue is the underlying breadth of the claims, and their novelty and non-obviousness. Formulation and drug-delivery patent claims can be as effective at providing appropriate protection for innovative inventions as are compound patents. Once just needs to be sophisticated about understanding the scope of the issued claims and their underlying validity.