Stopping TSC Onset and Progression 2B: Sirolimus TSC Epilepsy Prevention Study

Inclusion Criteria:

1. 0-6 months of age at the time of enrollment (subject must be <7 months ofchronological age at time of randomization and treatment initiation). Corrected agemust be at least 39 weeks (calculated by subtracting the number of weeks born before 40 weeks gestation from the chronological age).

2. Has a confirmed diagnosis of TSC based on established clinical or genetic criteria

Exclusion Criteria:

1. Prior history of seizures (clinical or electrographic) at the time of enrollment oridentified on baseline EEG.

2. Has been treated in the past or is currently being treated at the time of enrollmentwith conventional anticonvulsant medications (AEDs), systemic (oral) mTOR inhibitors (such as rapamycin, sirolimus, or everolimus), ketogenic-related special diet, oranother anti-seizure therapeutic agent, device, or procedure.

3. Has taken any other investigational drug as part of another research study, within 30 days prior to the baseline screening visit.

4. Has a significant illness or active infection at the time of the baseline screeningvisit

5. Has a history of significant prematurity, defined as gestational age <30 weeks atthe time of delivery, or other significant medical complications at birth or duringthe neonatal period that other than TSC would convey additional risk of seizures orneurodevelopmental delay (i.e. HIE, severe neonatal infection, major surgery,prolonged ventilatory or other life-saving supportive care or procedures).

6. Abnormal laboratory values at baseline (i.e., renal function, liver function, orbone marrow production) that are in the opinion of the investigator clinicallysignificant and may jeopardize the safety of the study subject.

7. Prior, planned or anticipated neurosurgery within 3 months of the baseline visit

8. Has a TSC-associated condition for which mTOR treatment is clinically indicated (i.e. SEGA or AML).

9. Subjects who are, in the opinion of the investigator, unable to comply with therequirements of the study.