The main purpose of this study is to evaluate the safety and tolerability of a Leucine-Enriched Essential Amino Acid (LEAA) Powder as an add-on to a classic ketogenic diet (KD) in pediatric and adult patients with refractory epilepsy.

This is a single center, single-arm, open label study to evaluate the safety, tolerability, and nutritional effect of Leucine-Enriched Essential Amino Acid powder (LEAA) when added to classical KD in pediatric and adult patients whose epilepsy is insufficiently controlled on the diet. The study will enroll patients who have previously been compliant with their classical KD regimen for at least 28 days prior to enrollment and have experienced some response (≥40% reduction in seizures), but not complete response (<90% reduction in seizures) to dietary management with KD. Study duration is 84 days and will have 3 remote study visits (Baseline- Remote Visit 1, Dose Adjustment- Remote Visit 2, and Final- Remote Visit 3) and a pre-screening communication via telephone/video.

Inclusion Criteria:

1. Male or female patients ages 2 years and up at enrollment.
2. A diagnosis of epilepsy, with at least 2 seizures per week according to the parent/guardian report to study staff and investigator medical notes if applicable. All seizure types allowed.
3. Under stable treatment with a classic ketogenic diet (KD) regimen with a KD ratio ≥ 1:1, with or without antiseizure medications (ASMs), for at least 28 days with documented, partial response (≥40% reduction in seizures), but not a complete response (<90% reduction in seizures) based on patient medical records or parental report.
4. Patient and/or parent/caregiver able and willing to follow all study procedures and successfully complete the study.

Exclusion Criteria:

1. Patients who have changed their KD regimen or antiseizure medication (ASM) or vagus nerve stimulation (VNS) within the last 28 days.
2. Allergy, sensitivity to, or inability to metabolize any component of leucine enriched essential amino acid (LEAA).
3. Those who are pregnant or breastfeeding.
4. Patients who have received an investigational drug or product or participated in a drug study within 4 weeks before the first dose of leucine enriched essential amino acid (LEAA) powder.
5. Patients who have a clinically significant condition or have had either clinically relevant symptoms or a clinically significant illness in the 4 weeks prior to the Baseline Visit 1, other than epilepsy, that would negatively impact study participation, collection of study data, or pose a risk to the patient including liver disease.
6. Patients with history of suicidal ideation in past 6-months and suicidal behavior in past 2-years