On Friday, Abbott Laboratories announced that it was pulling its obesity drug sibutramine from the market in the US, Canada and several other countries including South Africa, Hong Kong, Thailand and Australia. Readers will recall that sibutramine was suspended from the European market earlier this year.
Thus, a saga in which I have had the opportunity to be involved in over the past decade, comes to an unhappy ending.
From the start, sibutramine was viewed critically because of its “sympathomimetic” effects that resulted in an increase in heart rate by 2-4 beats/minute and, perhaps more importantly, an increase in blood pressure of a few mmHg. Although neither of these “side effects” were a major problem in the clinical use of sibutramine, it did raise all kinds of warning flags regarding the potential for cardiovascular risk. Thus, sibutramine was always contraindicated for use in people with existing (known) heart disease and/or uncontrolled hypertension.
Indeed, it was concern about these cardiovascular effects of sibutramine, that let the European regulators to demand that Abbott conduct a cardiovascular outcome study – SCOUT – the results of which (as blogged before) turned out to show a modestly increased risk for non-fatal heart attacks and strokes in the “high-risk” population that participated in this trial.
Despite the fact that the SCOUT study population was quite different from the people that I prescribed sibutramine to in my practice (with good results), the regulators decided that this drug may be too risky as a treatment for obesity.
As blogged recently, I do not think that this decision was warranted, as there is no doubt that sibutramine was a very effective and well-tolerated drug for some patients, who are now left with little choice but to regain the weight that they have been able to lose and keep off with this drug.
By “pulling” sibutramine from the market, the regulators have now probably made it very difficult for companies seeking to develop new anti-obesity drugs to actually bring treatments to market. Obviously, if regulators pull an effective drug like sibutramine, that has been on the market for over 10 years without a shred of evidence that it is actually harmful in the patients for whom it is intended, then they have just significantly raised the bar for newer treatments to be approved.
If there is anyone, who can be happy about this decision, it would be my surgical colleagues and the bariatric surgery industry, which can only rub their hands in gleeful anticipation of even more patients, who will now have no option but to make an appointment to see their friendly neighbourhood surgeon.
San Diego, CA
Disclosure: I have received consulting and speaking honoraria from Abbott Laboratories, the makers of sibutramine.
James WP, Caterson ID, Coutinho W, Finer N, Van Gaal LF, Maggioni AP, Torp-Pedersen C, Sharma AM, Shepherd GM, Rode RA, Renz CL, & SCOUT Investigators (2010). Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects. The New England journal of medicine, 363 (10), 905-17 PMID: 20818901