Long-term seizure outcomes and factors associated with response to adjunctive everolimus in TSC-associated epilepsy

BACKGROUND: Everolimus, a mechanistic target of rapamycin (mTOR) inhibitor, is increasingly used in tuberous sclerosis complex (TSC)-associated epilepsy; however, long-term real-world outcomes and factors associated with favorable response remain unclear. This study aimed to evaluate the long-term seizure outcomes of adjunctive everolimus and explore clinical factors associated with treatment response. METHODS: We retrospectively recruited 21 patients with active TSC-associated epilepsy receiving adjunctive everolimus and assessed seizure outcomes during follow-up. Clinical characteristics were compared between responders and non-responders at 1 year after treatment initiation. RESULTS: Over a median treatment duration of 72 months, responder rates ranged from 53.8% to 64.7%, and seizure-free rates ranged from 33.3% to 41.2%. Responders had fewer involved organ systems at baseline (median 3 vs. 4, p = 0.020) and lower anti-seizure medication burden (median 2 vs. 4, p = 0.045). Younger age at treatment initiation showed a trend toward improved response. CONCLUSION: Adjunctive everolimus was associated with sustained long-term seizure reduction in this real-world cohort. In exploratory analyses, fewer involved organ systems and fewer baseline ASMs were associated with favorable treatment response. These findings require validation in larger prospective cohorts.