This is a prospective, randomized, double-blind, placebo-controlled cross over study designed to evaluate the efficacy and safety of everolimus (trough 5-15 ng/mL) given as adjunctive therapy in patients with focal cortical dysplasia type II who already failed more than two antiepileptic drugs and surgery.

This study will assess the impact of everolimus to placebo on seizure frequency in focal cortical dysplasia type II. The number of patients who experience seizure reduction of 50% or more will be counted during last 4 weeks of each core phase.

This is a prospective, randomized, double-blind, placebo-controlled cross over study to evaluate the efficacy and safety of everolimus (trough 5-15 ng/mL) given as adjunctive therapy in patients with FCDII who already failed more than 2 antiepileptic drugs and surgery.

1. Baseline phase (4 weeks, week -4~-1): From Screening Visit (Week -4, V1) to starting titration visit at Week -1 (V2). For baseline seizure frequency calculations, the 4-week prospective period seizure counts will be totaled. Antiepileptic drug use will be assessed, and patients are required to be on a stable dose of AEDs. All patients who meet eligibility criteria will be randomized in a 1:1 ratio to treatment first arm and placebo first arm.

2. Core phase I (12 weeks, week 0~11) 2.1.Titration I period (4 weeks, week 0~3): Everolimus doses will be 4.5mg/m2 po daily given at first time and then during the 4-week titration period everolimus dose may get adjusted to reach trough concentration of 5 - 15 ng/mL. At week 2 (V3), 3 (V4) pre-dose PK blood samples will be taken for potential dose adjustments.

   2.2. Maintenance I period (8 weeks, week 4~11): After the completion of the titration period, the vast majority of patients are expected to continue at their current dose level during the entire 8 week maintenance period. However, the possibility of further titration does still exist, based on the planned pre-dose PK blood samples that will be collected every 4 weeks [week 4(V5) and 8(V6)].

3. Core phase II (12 weeks, week 12~23): After the completion of the core phase I, the everolimus first group will be changed to the placebo and the placebo first group will take everolimus. Dose titration method is same with core phase I.

4. Unblinded extension phase (29 weeks, week 24-52): After approval, all enrolled patients will be offered the opportunity to enter the unblinded extension phase of the study at the end of week 23 and continue everolimus. Everolimus will be provided to every study patient during the extension phase of 29 weeks. During the extension phase Everolimus doses will be titrated based on pre-dose PK blood samples at week 24 (V12), 28 (V13), 40 (V14), seizure frequency and everolimus tolerability. At week 52 (V15), the final analysis which include serum and CSF PK studies will be performed.

Inclusion Criteria:

• Male or female between the ages of 4 and 40
• Pathologically confirmed Focal Cortical Dysplasia type II (FCDII)
• Refractory seizure in spite of at least 2 antiepileptic drugs (AEDs) and surgery
• Subjects must have experienced at least 3 seizure events per month for two months retrospectively among 3 months prior to the baseline period in spite of using 1 AED or more.
• Must be at least one antiepileptic drug at a stable dose for at least 4 weeks at the start of the 4-week prospective baseline phase, remain on the same regimen throughout the baseline phase.
• VNS and ketogenic diet are allowed. If the patient is using VNS, device stimulator parameters must remain constant throughout the baseline phase. If the patient is on ketogenic diet, the ratio of the diet must remain constant throughout the baseline phase.
• At least 3 seizures throughout the baseline phase.
• Subjects and their legal guardians must have the ability to comprehend the informed consent form and be willing to provide informed consent. For subjects who are too young or unable to comprehend the written consent, a legal guardian who is able to describe and provide an understanding of the informed consent to the subject must sign the consent form on behalf of the subject.

Exclusion Criteria:

• Patients who need hospitalization due to causes not related to FCDII or epilepsy
• Patients who are pregnant or planning on becoming pregnant
• Patients with seizures secondary to causes other than focal cortical dysplasia
• Immunocompromised patients
• Patients who have received prior treatment with a systemic mTOR inhibitor
• Patients who do not follow up last one year
• Patients who do not show EEG abnormalities
• Patients with a history of non-compliance to medical regimens or who are considered potentially unreliable
• Patients with positive HBV Ag
• Patients who receive live vaccination during baseline study
• Patients with a known hypersensitivity to everolimus or other rapamycin-analogues(sirolimus, temsirolimus) or to its excipients
• Patients who have galactose intolerance, Lapp lactase deficiency, glucose-galactose malabsorption, or other genetic problems related to lactose digestion.

During baseline phase and core phase, double-blind is maintained. Only one independent investigator who check trough drug level of everolimus and and one pharmacist who dispenses IND will be exposed. All the rest of the researchers will be masked.