Inclusion Criteria:

1. Male or Female, age ≥18 to 65

2. Focal seizures, clinically defined as TLE

3. Has failed to achieve seizure control despite adequate trials of at least 2 ASDs at
appropriate doses

4. Currently on stable doses (at least 1 month) of approved ASDs

5. Single seizure focus confirmed as within one temporal lobe

6. For subjects entering Stage 1, the seizure focus is either a) in the non-dominant
hemisphere, or b) in the dominant hemisphere and the subject has a Rey Auditory Verbal
Learning Test (RAVLT) assessed within one year of screening, or at the screening
visit, that is at least 1.5 standard deviations below the population mean.

7. Seizure frequency averages ≥2 per 28-day period over the 6 months prior to screening.

Exclusion Criteria:

1. Epilepsy due to other and/or progressive neurologic disease

2. Significant other medical condition which would impair safe participation

3. Primary or secondary immunodeficiency

4. Suicide attempt in the past year

5. Severe psychiatric disorders

6. Chronic indwelling intracranial device

7. MRI indicating potential malignant lesion

8. Pregnancy, or currently breastfeeding

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 12/20/23. Questions regarding updates should be directed to the study team contact.