Does Eisai's epilepsy drug work? Yes and no

Some seemingly contradictory headlines are coming out of the American Academy of Neurology meeting in Honolulu, where Bloomberg reports that Eisai's epilepsy drug perampanel did not significantly reduce seizures in Phase III trials, while other reports from the same presentation say the drug worked well. The answer is somewhere in between. Bloomberg just chose to lead with the bad news, and other news organizations lead with the good.

First, Bloomberg's take on perampanel is that the drug, when given in lower doses, did not significantly cut seizure rates in epileptics who had already tried other drugs. Under European guidelines, the difference between the drug and placebo at the 12 and 8 milligram levels were not significant. Under U.S. standards, the 12 milligram dosage was effective. Patients who took 12 milligrams had a 14 percent reduction in seizures in 28 days. Those who took eight milligrams cut their seizures by nearly six percent.

Jacqueline French, director of the clinical trials consortium at New York University's epilepsy center, told Bloomberg that she does not see any problem with the differences between doses. "There was already a positive trial at lower doses," French said, adding that the FDA and the European Medicines Agency will "look at the entirety of the data," and should not have a problem approving the drug.

One problem that all reports mentioned, though, was a baffling difference between responses in Latin America compared with those in the United States and Europe. "In the Latin American arm of the study, perampanel was not shown to be better than placebo," equities analyst Stephen Barker told Bloomberg. "I would consider this to be something of a disappointment, and raises the risks in my mind that this drug may not get approval."

French, however, blamed the anomaly on patient selection problems in Latin America and said the regional differences should not present a problem. "If this drug is approved by the FDA, it will be another tool in our arsenal for combating or reducing seizures in people with difficult-to-treat epilepsy," French said in a news release.

The drug blocks receptors in neurons that transmit signals stimulated by glutamate in the brain. The receptors are believed to be involved in diseases that involve excess signaling, such as epilepsy. Eisai plans to submit the new drug for regulatory approval simultaneously in the United States and European Union

- see the news release from the American Academy of Neurology
- here's the Bloomberg story
- and another report from Medscape Medical News
- here's WebMD Health News' take on it