I had not been following the progress of Acorda's recently approved drug Ampyra for MS. (Well, more specifically, it's to improve gait and walking speed in MS patients). Opinion seems to be rather divided about how successful it'll be. On the one hand, new therapies for multiple sclerosis are certainly needed, but there's also room to argue about just how efficacious Ampyra really is.
I'm not going to fight that one out here, because we'll have the judgment of the market pretty soon. What I find interesting is the structure of this new drug: it's 4-aminopyridine. If there's a more simple, lower molecular weight structure approved within the next few years as an oral drug for anything, I'll be quite surprised.
This brings up several interesting topics relating to drug development and intellectual property. For one thing, this compound has been known for many years as a ligand for neuronal voltage-gated potassium channels, which is the mechanism by which it seems to work for MS patients. Some of these patients have experimented with it themselves over the years; the idea of using it for multiple sclerosis is certainly not new. (Here's a good history, taking things back a good 30 years through many players, with Elan a prominent one).
Secondly, it's not like the compound's chemical structure can be patented as such, either, since it's nowhere near novel. I have no idea of when 4-aminopyridine first makes its appearance in the chemical literature, but it's surely back into the 19th century. Nor is it anything like a rare chemical. For many years it was used as a bird-control poison. (High doses are fatal, but lower ones cause bird seizures that cause the rest of the flock to leave in consternation). We've got some on the shelf in our stockroom; I see in my Aldrich catalog that they're selling the 99% grade for $18/gram. And Aldrich is not exactly the world's low-cost chemical supplier. A railroad car full of the stuff could surely be arranged through someone, although it wouldn't exactly be pharmaceutical grade.
So. . .how then, some might wonder, does Acorda Therapeutics (partnered with Biogen Idec) get to charge several thousand dollars a year for Ampyra? (I don't think the actual price is known yet, but that's the best guess I've seen). One key factor is the bird-repellant aspect. Messing with ion channels in nerves is a tricky business, and 4-aminopyridine can and will cause trouble in humans if it's not dosed carefully. It's also (I believe) cleared pretty quickly, as you'd expect from something with that structure. Ampyra is a time-release formulation, an attempt to get enough of the compound into circulation over a long enough period, but without crossing over the line to too high a concentration, which could set off seizures and worse. Taking 4-aminopyridine from that railroad car and using that instead would be very much not recommended, considering what's waiting out there at inappropriate doses.
And that's Acorda's intellectual property. Plenty of work was done to find a good formulation for the drug, and Acorda spent the time and money to test one for safety and efficacy. They get to reap the fruits of their labors, if fruits there are. And that's what the market will decide for them. . .