Study: Eisai seizure drug delivers up to 5% weight loss

Could Eisai have an obesity drug just waiting to step onstage? The Japanese drugmaker's epilepsy treatment Zonegran helped patients lose weight--at least as much weight as patients in Arena Pharmaceuticals' ($ARNA) trial of its recently approved Belviq.

As Bloomberg reports, study patients who took 400 mg of Zonegran daily for a year lost 7.3 kg on average, significantly more than the 4 kg placebo patients shed. More than half of the patients using 400 mg lost at least 5% of their body weight. Belviq--which, ironically enough, will be marketed by Eisai in the U.S.--delivered a loss of 5% of body weight in 47% of patients.

Researchers also looked at a 200 mg dose of Zonegran, but it didn't appear to be effective. All study patients received diet and lifestyle counseling. The study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases, MedPage Today says.

The seizure drug does come with side effects, however; the study found that Zonegran patients experienced mood changes, memory problems, nausea and vomiting more often than placebo patients did. "The drug's benefit-to-risk ratio needs thoughtful and cautious assessment," the researchers wrote in the Archives of Internal Medicine (as quoted by Bloomberg).

The 225-patient study was the first randomized, controlled trial to look at Zonegran as a solo weight-loss drug, Bloomberg says. An earlier trial had looked at doses of 600 mg. Orexigen Therapeutics ($OREX) is testing a combination of Zonegran, known generically as zomisamide, and the antidepressant bupropion as a weight-loss treatment.

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