General Information

Vimpat tablets are specifically indicated as adjunctive therapy in the treatment of partial-onset seizures in patients with epilepsy ages 17 years and older. Vimpat injection for intravenous use is indicated as adjunctive therapy in the treatment of partial-onset seizures in patients with epilepsy ages 17 years and older when oral administration is temporarily not feasible.

Mechanism of Action

Vimpat is an orally available anticonvulsant. It selectively enhances slow inactivation of sodium channels and interacts with the neuroplasticity-relevant target collapsin-response mediator protein-2 (CRMP-2).

Side Effects

Adverse events associated with the use of Vimpat may include, but are not limited to, the following:

• Dizziness
• Nausea
• Diplopia
• Vision blurred
• Vomiting
• Fatigue
• Ataxia

Dosing/Administration

Vimpat is supplied as a tablet designed for oral administration or as a solution designed for intravenous administration. The recommended initial dose is 50 mg twice daily (100 mg per day). Vimpat can be increased at weekly intervals by 100 mg/day given as two divided doses up to the recommended maintenance dose of 200 to 400 mg/day.

Switching from oral to intravenous dosing
The initial total daily intravenous dosage of Vimpat should be equivalent to the total daily dosage and frequency of oral Vimpat and should be infused intravenously over a period of 30 to 60 minutes.

Switching from intravenous to oral dosing
At the end of the intravenous treatment period, the patient may be switched to Vimpat oral administration at the equivalent daily dosage and frequency of the intravenous administration.

Clinical Trial Results

FDA Approval
The FDA approval of Vimpat was based on the results of three clinical trials. These 12-week, randomized, double-blind, placebo-controlled, multicenter trials enrolled subjects with partial-onset seizures with or without secondary generalization and who were not adequately controlled with one to three concomitant AEDs. Study 1 compared doses of Vimpat 200 , 400 and 600 mg/day with placebo. Study 2 compared doses of Vimpat 400 and 600 mg/day with placebo. Study 3 compared doses of Vimpat 200 and 400 mg/day with placebo. Following an eight-week baseline phase to establish baseline seizure frequency prior to randomization, subjects were randomized and titrated to the randomized dose. During the titration phase in all three trials, treatment was initiated at 100 mg/day (50 mg given twice daily) and increased in weekly increments of 100 mg/day to the target dose. The titration phase lasted six weeks in Study 1 and Study 2 and four weeks in Study 3. In all three trials, the titration phase was followed by a maintenance phase that lasted 12 weeks. The primary end point was reduction in 28-day seizure frequency (baseline to maintenance phase) as compared to the placebo group. A statistically significant effect was observed with Vimpat treatment at doses of 200 mg/day (Study 3), 400 mg/day (Studies 1, 2 and 3), and 600 mg/day (Studies 1 and 2).