This One Isn’t Magic Either

Last week when I first heard reports about a new FDA-approved weight loss drug, I thought it was “old news” from June, when the FDA approved Belviq. When I learned that it was a new newly approved drug, I had to investigate again.

What Is It?

The latest drug is called Qsymia (maybe you aren’t allowed to eat until you are able to say it three times quickly?) and includes two active ingredients: (i) immediate-release phentermine hydrochloride (one of the components of fen-phen) and (ii) extended-release topiramate. According to the prescribing information, the activity of phentermine is similar to amphetamine, and acts as an appetite suppressant. Topiramate is used to treat migraines and some forms of epilepsy, and is known to have a “side effect” of weight-loss in those contexts.

Does It Work?

The prescribing information sets forth the results of two randomized, double-blind, placebo controlled studies that were conducted in obese patients (Study 1) and in obese and overweight patients with two or more significant co-morbidities (Study 2). Both studies had a 52 week treatment period. Study 1 tested daily doses of 3.75 mg/23 mg and 15 mg/92 mg, while Study 2 tested daily doses of 7.5 mg/46 mg and 15 mg/92 mg. All patients were advised to follow “a well-balanced, reduced-calorie diet to result in an approximate 500 kcal/day decrease in caloric intake” and were offered “nutritional and lifestyle modification counseling.”

The study looked at the percent weight loss from baseline and whether the patent achieved at least 5% weight loss from baseline. After 1 year of treatment, “all dose levels resulted in statistically significant weight loss compared to placebo,” and “[a] statistically significant greater proportion of the patients randomized to Qsymia than placebo achieved 5% and 10% weight loss.”

Study 1 patients achieving 5% weight loss:
Placebo: 17%
3.75 mg/day: 45%
15 mg/day: 67%

Study 1 patients achieving 10% weight loss:
Placebo: 7%
3.75 mg/day: 19%
15 mg/day: 47%

Study 2 patients achieving 5% weight loss:
Placebo: 21%
3.75 mg/day: 62%
15 mg/day: 70%

Study 2 patients achieving 10% weight loss:
Placebo: 7%
3.75 mg/day: 37%
15 mg/day: 48%

Interestingly, “[a] substantial percentage of randomized patients withdrew from each study prior to week 56, 40% in Study 1, and 31% in Study 2.”

What Are The Possible Side Effects?

The prescribing information includes a discussion of possible side effects including:

• Fetal Toxicity
• Elevation in Heart Rate
• Suicidal Behavior and Ideation
• Acute Angle Closure Glaucoma
• Mood and Sleep Disorders
• Cognitive Impairment
• Metabolic Acidosis

According to an ABC News report, the FDA originally denied approval due to concerns about some of these potential side effects, but granted approval after the manufacturer gave “assurances that the company would provide detailed information to physicians about the risk of the drug and how to manage them.”

Another Option

The approval of Qsymia gives obese patients another option to discuss with their doctors. Hopefully this new drug will prove to be safe and effective in the long run.