Intravenous Lacosamide Compared With Fosphenytoin in the Treatment of Patients With Frequent Nonconvulsive Seizures

Utility of Intravenous Lacosamide Compared With Fosphenytoin in the Treatment of Patients With Frequent Nonconvulsive Seizures

This a phase 2 study comparing the efficacy of intravenous (IV) lacosamide (LCM) with IV fosphenytoin (fPHT) in controlling frequent nonconvulsive seizures (NCSs), the Adverse Events profile of LCM compared with fPHT when used to treat frequent NCSs, and length of stay in an intensive care unit for subjects treated with LCM versus subjects treated with fPHT. The trial will include a preacute-treatment period, an acute-treatment period, a postacute-treatment period, and a long-term follow-up period.

Exploratory, prospective, multicenter, open-label, randomized study, in which the physicians who are interpreting cEEGs for treatment purposes and the central reviewers who are providing final cEEG interpretation for study purposes are all blinded to treatment.

Initial LCM/maintenance doses: Subjects will receive a 400-mg IV initial bolus over 30 minutes, followed by a 2-hour post-dose observation-only period. If a breakthrough seizure occurs in the 6 hours following the 2-hour post-dose observation-only period, the subject will receive a 200-mg rebolus over 30 minutes. Regardless of whether a rebolus was administered, a maintenance dose of LCM will be started 12 hours after the initial bolus, and it will continue every 12 hours throughout the acute-treatment period. The daily maintenance dose will be equivalent to the total IV bolus per day (400 mg if no rebolus was administered or 600 mg if a rebolus was administered), divided into 2 doses. After completion of the acute-treatment period, daily maintenance with an AED will be at the discretion of the treating physician.

Initial fPHT/maintenance doses: Subjects will receive a 20-mg PE/kg IV initial bolus at a rate no greater than 75 mg PE/minute, followed by a 2-hour post-dose observation-only period. If a breakthrough seizure occurs in the 6 hours following the 2-hour post-dose observation-only period, the subject will receive a 5-mg PE/kg IV rebolus at a rate no greater than 75 mg PE/minute. Regardless of whether a rebolus was administered, a maintenance dose of fPHT will be started 12 hours after the initial bolus, and it will continue every 12 hours throughout the acute-treatment period. The daily maintenance dose will be 5 mg PE/kg, divided into 2 doses. After completion of the acute-treatment period, daily maintenance with an AED will be at the discretion of the treating physician.

Crossover/maintenance doses: If a subject does not receive a rebolus but has a seizure within 24 hours following the 2-hour post-initial-dose observation-only period, he or she will "cross over" and begin receiving the other drug, ie, the one not originally administered. If a subject does receive a rebolus and has another seizure within 24 hours following the 2-hour post-rebolus observation-only period, he or she will also cross over to the other drug. If crossover occurs, the subject will "start over" with the second drug, going through the same observation-only period and rebolusing, if necessary. If a subject crosses over and starts receiving the second drug, in addition to receiving every-12-hours maintenance doses of the drug originally administered, the subject will also receive maintenance doses of the second drug every 12 hours, beginning 12 hours after the first dose of the second drug.

Inclusion Criteria:

1. Have the capacity to understand and sign an institutional review board (IRB)-approved informed consent form (ICF) or have a legally authorized representative (LAR) available to sign on behalf of the subject.

2. Are undergoing cEEG monitoring in the neurologic intensive care unit (NICU) or other closely monitored environment.

3. Are experiencing NCSs according to the following criteria:

   • At least 1 ESz lasting at least 10 seconds, with or without clinical correlates, occurring within the last 6 hours of cEEG monitoring.
   • If a new AED has been started, ESzs must have occurred per the preceding bullet point at least 2 hours after starting that AED.
   • If individual ESzs are not well defined, ESz time is at least 10 seconds and less than 30 minutes per hour of cEEG recording.

4. Are being considered for treatment with an IV AED.

5. Are at least 18 years old.

Exclusion Criteria:

1. Treatment with PHT, fPHT, or LCM in the last 7 days.
2. Contraindication for the use of fPHT or LCM.
3. Ongoing generalized convulsive status epilepticus (SE) (more than 2 generalized tonic-clonic seizures within 30 minutes without recovery to baseline or 1 seizure lasting longer than 10 minutes).
4. Episodes of SE, defined as at least 30 minutes of ESz activity in 1 hour, in the last 6 hours.
5. Encephalopathic event secondary to acute anoxic/hypoxic event.
6. Undergoing therapeutic hypothermia protocol.
7. Continuous EEG monitoring showing only periodic discharges or rhythmic delta activity without clear ESzs (for definitions of periodic discharges, rhythmic delta activity, and ESzs, see the Manual of Operations).
8. Electroencephalographic seizures consistent with typical absence seizures.
9. Evaluation for spell characterization or surgical treatment for epilepsy.
10. Pregnancy.