Wednesday, May 01, 2013

OxyContin And The Art Of 'Evergreening'

A few weeks back, we wrote about the Indian Supreme Court's rejection of Novartis's attempt to use "evergreening" to prolong its patent on Gleevec, sold as Glivec in India. That term refers to the trick of making small changes to a drug, usually one about to come off patent, in order to gain a new monopoly that extends its manufacturer's control over a medicine. But how does that work in practice?

A recent story in The New York Times answers that question for us. It concerns the painkiller OxyContin, produced by Purdue Pharma. The main ingredient was supposed to be released gradually, for extended pain relief, but some inventive types started crushing the pills in order to get a big, single hit -- often with fatal results. So in 2010, Purdue Pharma came up with a new physical formulation that was designed to make it harder to mis-use in that way, and obtained a patent on it. Fair enough, you might think: surely it's just trying to stop the abuse of its products and save lives? Well, maybe, but as The New York Times story now tell us:

In a major policy move, the Food and Drug Administration [FDA] said Tuesday that it would not approve generic versions of the powerful narcotic OxyContin, the painkiller that symbolized a decade-long epidemic of prescription drug abuse.
That's because there was apparently a fear that the generic versions would be abused in the same way as the older formulation from Purdue. What's interesting here is the FDA's timing:
The decision by the F.D.A. came on the day when the patent for the original version of OxyContin was set to expire. That would have allowed generic producers to introduce their own version of the formulation. F.D.A. officials said that several producers had applications to sell a generic form of OxyContin pending before the agency.
Of course, now there won't be any generic versions -- at least, not immediately -- and so the price of OxyContin probably won't drop precipitously, and Purdue will keep making a nice profit from it.
That is a perfect demonstration of how evergreening works. Getting a new patent on a tweaked version of a drug that effectively extends a company's monopoly control beyond the original patent term is not enough on its own; what's then needed is some reason why the much cheaper generic versions of the original drug without the tweak are kept from the market. In this case, it's because they don't offer a formulation that combats mis-use.

Of course, it's good news that tamper-resistant versions will now be the norm, since that is likely to save lives. But as the New York Times article writes:

While companies like Purdue Pharma insist the public's health is their main concern, others note that producers introduced tamper-resistant versions of their products just as the drugs were about to lose patent protection.
I suspect we may see more of these interesting coincidences as other profitable drug patents are about to expire, and their manufacturers start to come up with yet more ways to "evergreen" them.

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