Experts from the Food and Drug Administration’s (FDA) Endocrinologic and Metabolic Drugs Advisory Committee are set to review the safety and efficacy of a weight loss pill made by Sanofi-Aventis in a meeting tomorrow.
The pill, which contains the active ingredient rimonabant was approved last year in Europe where it sells under the brand name Accomplia. If approved in the US it will be marketed as Zimulti.
Rimonabant is a cannabinoid receptor antagonist; that is it blocks the cannabinoid type 1 (CB1) receptors in the brain that control hunger. So taking the drug reduces hunger and suppresses appetite. The drug may also help to control the urge to smoke, but approval is not being sought for this use.
As with all drug safety and efficacy reviews, the purpose of the panel meeting is to weigh up the benefits against the risks. On the benefits side there is now evidence that the 20 milligram a day version of Zimulti helped people to lose weight and reduce levels blood sugar, cholesterol, and fats.
On the risks side, the manufacturer has submitted results of clinical trials that showed an elevated risk of suicide and suicidal thoughts in patients who took Zimulti compared to those who took a placebo.
In a recent shareholder meeting, the drug manufacturer emphasized that Zimulti/Accomplia is not a “cosmetic” for those seeking to lose a little weight to improve their shape or look slimmer. However, market experts are predicting that most of the consumers will be in this category.
In Europe the drug was approved for use under prescription only as part of a diet and exercise regimen for adult patients who are:
- Obese, that is with a body mass index (BMI) greater than or equal to 30 kg per square metre, or
- Overweight, that is with a BMI greater than equal to 25 kg per square metre and who also have one other risk factor, such as type 2 diabetes or abnormal levels of fat in their blood (dyslipidaemia).
For example, a person who is 5 feet 10 inches (1.78 m) tall and weighs 250 pounds (113 kg) is classed as obese and would qualify to receive the drug as part of an exercise and diet programme to lose weight. A person who is 5 feet 5 inches (1.65 m) tall and weighs 170 pounds (77 kg) is classed as overweight but not obese, so they would only qualify to receive the drug if they also had another risk factor, for instance if they had type 2 diabetes.
According to the Centers for Disease Control and Prevention (CDC), the prevalence for overweight and obesity among American adults and children has risen sharply since the 1970s. Among adults this figure has risen from 15 per cent of the populaton in the late 1970s to 33 per cent in the last few years. That means one in three adult Americans is overweight or obese.
Zimulti has been tested in four trials of 6,600 overweight and obese patients weighing on average between 94 and 104 kg ((207 to 229 pounds). The results of these trials were the basis for the European approval.
All four studies compared the effect of the drug on weight loss with that of a placebo for 12 to 24 months. One study looked in particular at the drug’s impact on blood fat and another on type 2 diabetes. A third study looked at how the weight loss could be maintained in the second year.
After one year, all patients on Zimulti lost more weight than the ones who took the placebo. They lost on average 4.9 kg (10.8 pounds) more than the placebo patients, except for the diabetic study where the weight loss compared with placebo was 3.9 kg (8.6 pounds). The drug also showed ability to reduce risk of putting weight back on.
Another set of trials have also been carried out in 7,000 patients to test the ability of the drug to help smokers quit. The durations ranged between 10 weeks and one year, and the outcome measures included cessation and relapses in the second year. However, the results from these trials were inconsistent and the company withdrew its European application for the drug to be considered as an aid for smoking cessation.
The manufacturer is continuing with post-market monitoring of the drug, which is being used in South America as well as Europe. Nearly 110,000 people have been prescribed the drug since the start of March this year.
Part of the submission to the FDA panel includes a risk management plan to which excludes the drug from being prescribed to patients with a psychiatric illness. People who suffer from epilepsy may also need to be careful.
When the FDA receives the panel’s decision it does not have to follow it, although in most cases it does. According to the manufacturer, the FDA will give its decision by the end of July.
However, experts following this story closely are suggesting that the FDA panel may ask for further data on the drug’s safety and this would delay the decision even further.
Written by: Catharine Paddock
Writer: Medical News Today