Post-Kainic Acid Status Epilepticus-Induced Spontaneous Recurrent Seizures Model (rat) – Phase II

This paradigm utilizes the automated feeder system to deliver drug-in-food on a fixed schedule. The procedure for the induction of chronic epilepsy and implantation of the telemeter in the rats is the same as described for the Phase I study. Doses are selected based on performance of the drug in Phase I study and if available, other information such as pharmacokinetic profile. Animals are split into two groups and given 40 g /kg body weight per day of either drug or control food for two weeks. The amount of drug in each gram of food is fixed to make the appropriate dose. Four meals are given per day, at a rate of 10 g/kg, regardless of the pharmacokinetic profile of the drug. This is to ensure proper consumption of a single dose. In the first week (week 1), a baseline seizure rate is determined while animals are fed control food. During the following two weeks (week 2-3), all the rats are fed drug food. After treatment is completed in week 3, rats will be fed control food and monitored for 3-5 days (washout period; week 4). This process (week 1-4) is repeated for up to four separate testing runs in the same cohort.

EEG data is reviewed daily, in a blinded fashion. Data channel order is randomly scrambled and unlabeled. A list of potential detected events is automatically generated overnight by an automated seizure detection algorithm. The reviewer goes through these detected listings in a sequential order and scores any positive detected events. Data is accumulated at the end of the paradigm and analyzed via a MATLAB GUI. Seizure burden and seizure freedom are the primary outcome measures. Seizure freedom is defined as zero seizures occurring between the first dose of drug and 12 hours following the final dose.

Prior to conducting this test, a tolerability assessment is performed to identify possible toxicity of the drug when given in food over multiple days in four rats that have experienced KA-induced status epilepticus but has a low spontaneous seizure burden and hence not included in the above study. Doses are selected based on performance of the drug in Phase I study. Four meals are given per day, at a rate of 10 g/kg, for four days. Pellet counts are performed one hour following the second and third meals, and unconsumed pellets are removed from the cage. If the average consumption for animals is less than 90%, the experiment is extended to a 7-day trial to determine if consumption increases over the trial duration. On the second to last day of treatment (day 3 or 6), rats receive a functional observation battery, i.e., modified Irwin test assessment one hour after the second or third meal. Additionally, animal welfare checks are performed at each pellet count. Animals are weighed at the first pellet count of the day. If any untoward effects are observed (rated by the experimenter as greater than mild in severity) and persist to the next dose, treatment is terminated. Mild tolerability effects are defined as those that do not interfere with normal behaviors (grooming, drinking, and responding to auditory or handling stimuli). Moderate to severe toxicity is defined as adverse effects that interfere with normal behaviors. If a screening dose exhibits toxicity that persists at the final dose, e.g., notable impairments (greater than mild) observed at the final assessment, or if treatment is terminated due to adverse effects prior to the final dose, a lower dose will be recommended for screening for Phase II study. If the compound at the tested dose demonstrates palatability (greater than 90% average consumption), tolerability, and efficacy, it will be considered ready for the Phase II study. Rats used for the tolerability test are not included in the above test.