A Single-Arm Open-Label Clinical Trial on the Efficacy and Safety of Sirolimus for Epileptic Seizures Associated with Focal Cortical Dysplasia Type II: A Study Protocol

Efficacy of sirolimus for epileptic seizures in childhood associated with focal cortical dysplasia type II

OBJECTIVE

The efficacy of the mechanistic target of rapamycin inhibitor, sirolimus, was recently reported for patients more than 6 years of age by Kato et al. We evaluated the efficacy and safety of sirolimus in a 2-year-old patient with recurrent focal seizures with impaired consciousness after focal cortical dysplasia (FCD) type IIa resection.

METHODS

The patient was a 2-year-old girl who had recurrent seizures after undergoing FCD resection at 4 months of age. The initial dose of sirolimus was 0.5 mg/day and was gradually increased using the trough blood concentration before oral administration as an index, and evaluation was performed at 92 weeks.

RESULTS

The trough blood level of sirolimus was increased to 6.1 ng/mL and maintenance therapy was started at 40 weeks. Focal seizures with impairment of consciousness with tonic extension of the limbs decreased. No critically serious adverse events occurred.

CONCLUSION

Sirolimus was effective against epileptic seizures from FCD type II even for a child under 5 years of age. There were no critically serious adverse events and administration could be continued.

Sirolimus for epileptic seizures associated with focal cortical dysplasia type II

Objective

To determine whether sirolimus, a mechanistic target of rapamycin (mTOR) inhibitor, reduces epileptic seizures associated with focal cortical dysplasia (FCD) type II.

Methods

Sixteen patients (aged 6–57 years) with FCD type II received sirolimus at an initial dose of 1 or 2 mg/day based on body weight (FCDS‐01). In 15 patients, the dose was adjusted to achieve target trough ranges of 5–15 ng/mL, followed by a 12‐week maintenance therapy period. The primary endpoint was a lower focal seizure frequency during the maintenance therapy period. Further, we also conducted a prospective cohort study (RES‐FCD) in which 60 patients with FCD type II were included as an external control group.

Results

The focal seizure frequency reduced by 25% in all patients during the maintenance therapy period and by a median value of 17%, 28%, and 23% during the 1–4‐, 5–8‐, and 9–12‐week periods. The response rate was 33%. The focal seizure frequency in the external control group reduced by 0.5%. However, the background characteristics of external and sirolimus‐treated groups differed. Adverse events were consistent with those of mTOR inhibitors reported previously. The blood KL‐6 level was elevated over time.

Interpretation

The reduction of focal seizures did not meet the predetermined level of statistical significance. The safety profile of the drug was tolerable. The potential for a reduction of focal seizures over time merit further investigations.