I haven't mentioned Pfizer's inhaled insulin project in a while, but a few weeks ago they got the stuff approved, at (very) long last. The development of Exubera, which is certainly a cheerful brand name, has been anything but uplifting, though Here's a piece I did three years ago, when the story already seemed to have been going on for a long time.
Insulin, of course, is the very definition of a well-established drug, but that's only if you inject it. Slowing things down have been problems which are unique to inhaled powders: the effect on lung function over time, the changes in dosage under suboptimal conditions (allergy, flu, etc.), and the reproducibility of the dose. These are particularly worrisome for insulin, which is a tough situation: it's vital to its users, and it has a lower margin for error (both under- and over-dosing) than most other drugs. As I put it in that 2003 post, if you take twice as much aspirin as you should, it'll be rough on your stomach. If you take twice as much insulin, you're going to end up on the floor (and there had better be someone around with a candy bar).
You can see this troubled history in the drug's labeling, which Frederick Cohen at Crownstone has been going over. To pick one interesting detail, patients will be required to have a baseline pulmonary function test before starting the drug, with monitoring thereafter. And this brings up the current worry: how much will Exubera (and its baggage) cost, and who's going to pay for it? The product won't be launched until mid-year, and no one knows quite what its price will be. Pfizer's just saying that it will be "competitive", an answer which is synonymous with "Go away", but you can find estimates of up to four times the cost of injectable insulin (my guess is 2.5x). Call it a convenience premium. Will it fly?
Well, here's a piece in Business Week that's enough to make you wonder. It's written by a pair of consultants from the Bruckner Group, an outfit that's very big on outcome-based medicine, and from that perspective they think Exubera's in trouble even before it launches:
". . . Based on our analyses and interviews with major managed-care decision-makers, we expect that payers will either dramatically limit Exubera's availability to patients, impose very high co-payments, or reject coverage of it outright. . .For Exubera to achieve widespread preferential formulary status, payers will need to see a credible and compelling value proposition rather than an argument centered on patient convenience. The crux of the issue is whether an inhaled therapy will improve compliance and lead to significant improvements in patient health."
As they point out, the data on other inhaled therapies isn't too reassuring. Studies have indicated that asthma inhalers, for example, are often misused, both quantitatively and qualitatively. The Flumist inhaled flu vaccine has also been a disappointment compared to its injectable competition.
Pfizer may be counting on its (justly) famous marketing powers to put Exubera over. If the landscape, though, really is changing to more rigorous cost/benefit calculations, that might not do the trick. I realize that the BW authors have an interest in promoting this viewpoint, but I hope that they're on to something. I'd rather see more of the competition between drug companies taking place over medical evidence and financial benefit, rather than the size of the sales forces. Salesmanship alone can't put over a lousy drug. But it can take away from the issues that really should be decisive.
Tomorrow we'll take a look at how this applies to oncology, where things are getting really interesting. . .