The first step in tackling obesity is a change in diet and exercise; however, many obese people find it difficult to maintain short-term weight loss and the utilisation of pharmacological drugs for obesity treatment may be employed, with surgery as a last resort. However, for obese people who require weight loss drugs to help with weight management, options are limited. Two new weight loss drugs for obesity have reported positive results in late stage trials, and it is hoped that these new obesity treatments will expand current obesity drug options in the near future.
Obesity and Comorbid Conditions
Obesity is defined as having excess body fat and is often associated with comorbid conditions, such as diabetes, high blood pressure, stroke and high cholesterol. Research has shown that even a modest weight loss of 5-10% can help improve these conditions and also lower the risk for heart disease.
Current Weight Loss Treatment - OTC Diet Pills
There are a multitude of diet pills available over-the-counter (OTC), and while some may have been studied in clinical trials claiming they aid weight loss, they have not been officially approved as weight loss drugs by the Food and Drug Administration (FDA). Therefore, the real clinical effectiveness of diet pills such as these is unknown.
Current Obesity Treatment - Prescription Weight loss Drugs
Even the FDA approved weight loss drugs have limited effectiveness, with a maximum weight loss of 10% of body weight achieved. These treatments are also not without unpleasant side effects.
Current obesity treatments include weight loss drugs sibutramine and phentermine, which act as appetite suppressants, but can also cause dry mouth, insomnia, high blood pressure and headache.
Another of the available drugs for weight loss is orlistat, which is available in both prescription form as Xenical and OTC as Alli (the only FDA approved OTC weight loss drug available). Orlistat is a lipase inhibitor, and acts in the gut to stop fat being absorbed. Therefore the side effects seen with appetite suppressants are not present, but other unwanted effects may occur, such as loose stools, flatulence and abdominal discomfort.
New drugs for weight loss other than these have failed to gain FDA approval or have previously been removed from the market due to risks associated with these new obesity treatments. One prominent case was that of rimonabant (Acomplia), a new weight loss drug that never gained access to the US market based on its association with a high number of psychiatric side effects. The new obesity treatment was available in Europe for some time, but a re-evaluation of clinical safety data by authorities led to rimonabant's removal in 2008.
As such, pharmaceutical companies are now embarking on developing new drugs for weight loss that have fewer side effects.
What’s in the Pipeline for New Obesity Treatments?
Two of the most promising new weight loss drugs in the pipeline are Qnexa and Contrave. These new obesity treatments are among the most advanced in clinical development, and positive results from late-stage trials have recently been reported that suggest each of these new weight loss drugs meets the FDA criteria to be considered an effective treatment for weight management. (The criteria include that a new drug for weight loss must show twice the number of patients in the treatment group achieve more than 5% weight loss compared to the control group of patients, or that there be at least a 5% difference in weight loss between the treatment and control groups.)
The pipeline new obesity treatments, Qnexa and Contrave, each contain two active ingredients that are already available separately. Contrave consists of the antidepressants bupropion and naltrexone, while Qnexa contains the appetite suppressant phentermine in combination with the anticonvulsant topiramate.
Each of the new drugs for weight loss has been studied for their effectiveness at inducing weight loss in large placebo-controlled trials, where obese patients were treated with the active drug or a placebo (control). All pbese patients were asked to follow a reduced-calorie diet. in combination with taking the new weight loss drug or placebo.
Effectiveness of New Weight Loss Drugs, Qnexa and Contrave
In two separate studies, analysis of patients who completed one year of treatment with Contrave achieved an average weight loss of 8.1% (COR-I) and 8.2% (COR-II), compared with 1.8% and 1.5% for the control groups in each respective study. Trials for the new weight loss drug, Qnexa, showed more positive results, with average weight losses of 14.7% (EQUIP) and 13.2% (CONQUER) for patients that received the new obesity treatment, compared with 2.5% and 2.4% for those who took placebo, respectively. Furthermore, sub-analysis of the data showed that 43% and 39% of Qnexa treated patients achieved weight loss of at least 15% of their body weight in the EQUIP and CONQUER trials, respectively.
Both Qnexa and Contrave saw around three times the proportion of patients treated with these new weight loss drugs lose at least 5% of their body weight compared with the control group for trials with each drug.
Additional benefits to weight loss were also observed. The new obesity treatments, Qnexa and Contrave, both improved cardiovascular and metabolic risk factors, while Qnexa had the additional benefit of reducing inflammatory risk factors.
Qnexa and Contrave – Side Effects of New Drugs for Weight Loss
Both Qnexa and Contrave were associated with side effects. Side effects for Qnexa were typical of appetite suppressants, including dry mouth, tingling, constipation and insomnia. Contrave was associated with nausea, headache and constipation. Importantly, however, there were no differences in the proportions of depressed episodes reported in the control and groups treated with the new weight loss drugs for trials of either new obesity treatment.
Which New Weight Loss Drug to Chose?
The perfect new weight loss drug would be one that works effectively for weight loss as well as weight maintenance following weight loss, with no side effects. Therefore physicians and patients will have to weigh up the new obesity treatments in light of these factors. Nonetheless, with drug companies planning to market these drugs in the near future, physicians and patients will be presented with a lot more choices for obesity treatment than currently on offer, renewing the hope for those still struggling to combat their weight, having tried and failed on existing obesity treatment options.
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Christine Redmond - My interest in science and healthcare has seen me working in the laboratory with tiny cells and DNA to helping set up a cancer clinical ...
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