Anup Patel, MD: The perampanel FREEDOM trial is a very interesting study done in Asia. In this study, they wanted to look at perampanel as monotherapy in 2 doses: 4 mg per day and then 8 mg per day. Now, what’s important to know is this is a phase 3 study. It had a pretreatment at baseline, followed by a titration and maintenance phase. During the maintenance phase, they looked at anybody who had seizures. If they did, they were able to have their dose titrated up to the 8 mg per day. But they were actually able to look at safety and efficacy in both ranges. After the additional 30 weeks of treatment, and during the entire maintenance phase, they did see significant patients with seizure-freedom rates.
The efficacy, or at least this freedom from seizures, in patients on 8 mg per day of perampanel was much higher than the 4 mg per day, and hovered around 70% or more. The other important findings from this study was that this medication was well tolerated. It had some adverse events, which were commonly seen in other antiseizure medication trials. Specifically, being tired was another common event. More importantly, they did not report significant behavioral changes, which has been seen and published in other studies looking at perampanel. The takeaway from this study is that either 4 mg or 8 mg of perampanel may be a good option as monotherapy for patients with partial-onset seizures with secondary generalization.
The other important aspects of this abstract are that the median seizure reductions were not reported—and those are the normal end points that we usually report, as it relates to studies in the United States—nor did the authors comment on the responder rate, which is the percentage of patients who had at least a 50% or more reduction of their seizures. One can conclude that would be very high, given the fact that 64% of patients on 4 mg per day had no seizures during the maintenance phase of the study, and 75.3% of patients on 8 mg had no seizures during the duration of the study. That does suggest there is a significant seizure-freedom rate as it relates to both doses in the patients who were given this medication as monotherapy. That’s very important to note because those are very high seizure-freedom rates, which makes this medication a potential option for this population of patients with partial-onset seizures.