CB1 antagonist update, and a poor excuse
I recently reported on Sanofi-Aventis’ decision to pull rimonabant from EU shelves. Since then, S-A has stopped all rimonabant clinical development.
I also told you that clinical success of Pfizer’s Phase 3 CB1 antagonist, CP-945,598, seemed dubious. Yesterday, Pfizer pulled the plug on their drug, citing “changing regulatory perspectives on the risk/benefit profile of the CB1 class and likely new regulatory requirements for approval.” Their public reasoning is arguably disingenuous, however, since the drug development community at large has known for at least six years that regulators would demand no less than squeaky clean safety profiles for drugs approved on the basis of weight loss, even with concomitant improvements of glycemia and/or blood pressure. And that, in the absence of such squeakiness, efficacy would likely have to be demonstrated as hard (cardiovascular) outcomes. But I guess when the alternative is to admit that the company failed to act quickly on the emerging profile of the drug (class), blaming the program’s failure on risk-averse regulators is an understandable response.
I don’t intend to single out Pfizer for reproach. however. Pfizer’s failure to anticipate and/or act on the realities of obesity drug development until well into Phase 3 is simply illustrative of a general institutional inertia that likely explains much of the industry’s increasingly poor returns on R&D investment. Pfizer, and presumably every other major, now recognizes their failings in this regard and are taking some steps to try to remedy the problem.
