Efficacy and safety of everolimus in patients younger than 12 months with congenital subependymal giant cell astrocytoma

Tuberous sclerosis complex (TSC) is a multisystem genetic disorder that activates mammalian target of rapamycin and produces tumor growth in several organs. We present five patients younger than 12 months who were diagnosed with TSC and treated with everolimus (EVL), after which congenital subependymal giant astrocytoma (cSEGA) promptly regressed in all patients. All patients achieved at least 50% reduction in the volume of cSEGA within 6 months. The most rapid reduction of cSEGA volume (79.1%) was found during the initial 3 months of EVL treatment. Patients underwent EVL treatment for an average of 27 months (range: 4-55 months). Mean EVL maintenance dose was 1.35 mg per day. EVL blood trough concentrations ranged from 2.0 to 11.7 ng/ml. The cSEGA became larger after discontinuing EVL in two patients. In all four patients who had multiple cardiac rhabdomyomas (CRMs), the CRMs showed accelerated regression after receiving EVL. Adverse events were noted in four patients: infection, stomatitis, and increased triglycerides. Four patients had febrile status epilepticus, which occurred during acute encephalopathy in a patient, and after discontinuing EVL in another. Three patients were still receiving EVL at their latest evaluations. Maintenance therapy with EVL is an effective therapeutic option for patients with cSEGA, and moreover may have additional favorable effects on other complications, even in early infancy; however, adverse effects should be carefully monitored.