That Pfizer article I was blogging about yesterday made much of their new HDL-raising therapy, torcetrapib, and the company's plans to only sell it as a combination therapy with Lipitor. That's been a controversial idea, naturally, given the number of people (and the number of insurance companies) who would rather be able to take it alone or with the statin of their choice.

But according to today's New York Times, Pfizer has dropped the idea. Torcetrapib (I await announcement of its brand name, so I don't have to type that) will be available alone as well as in combination.

The drug is an inhibitor of cholesteryl ester transfer protein, CETP, which is mostly bound to HDL particles in the blood. It spends its days shuffling cholesteryl esters and triglycerides among different lipoproteins, generally evening things out among the various lipoprotein fractions. But cholesteryl esters mostly come in as a component of HDL, so the overall effect of CETP is to transfer the cholesterol compounds away from HDL to LDL and other fractions. (Triglycerides, for their part, tend to be moved in the opposite direction). If you could inhibit CETP, the HDL-bound fraction of total cholesterol should increase, and that it does. And since it's been known for some time that loss-of-function mutations in CETP seem to be cardioprotective, the mechanism seems pretty sound. The drug is expected to be huge.

So why did Pfizer about-face? The Times article quotes a Pfizer official as saying that all the criticism was certainly a factor - "We didn't appreciate how this would be perceived", he said. That sounds rather unlikely to me, given that a child of ten would have been able to immediately appreciate how Pfizer's bundling strategy would be perceived. No, I think it's time to apply my general rule that most questions that start with "I wonder how come they. . ." can be answered by "money".

In this case, it may well have been some advance pushback from the various managed-health organizations. Everyone involved knows that this is about the time a decision would have to be made on whether torcetrapib would be sold solo or not, given the regulatory and manufacturing lead times, and I'm sure some strong opinions on the subject were quietly exchanged. Like any other company, Pfizer does nothing, or at least tries to do nothing, that is not in the best interest of Pfizer, and they've no doubt decided that bad publicity is one thing, but putting a possible limit on their new drug's sales potential is quite another.