Preventative treatment of tuberous sclerosis complex with sirolimus: Phase I safety and efficacy results

Treating subependymal giant cell astrocytoma in patients with tuberous sclerosis complex: an update of the literature

INTRODUCTION

Subependymal giant cell astrocytomas (SEGAs) are one of the predominant features of the tuberous sclerosis complex (TSC). Before the use of mTOR inhibitors (mTORi; everolimus and sirolimus) in TSC, many patients had to undergo surgical operations (both preemptively and emergently). However, with mTORis gaining increased use, the role of medical and surgical therapy in SEGA is unclear.

AREAS COVERED

The authors have based this review on publications listed in PubMed that delve into the role of surgery and mTORi in the treatment of SEGAs.

EXPERT OPINION

There is no sizable head-to-head comparison of surgery and medical therapy in treating SEGA. Factors that reduce the ability to do these types of studies are the lack of uniform diagnosis of SEGA, provider preference for treatment, and variability in each treatment group (dosing of mTORis and various surgical providers). However, with the safety of mTORi, the authors recommend starting mTORi therapy for any growth in a nodule on serial scans and relying on surgery only for failed mTORi therapy.

An overview of the value of mTOR inhibitors to the treatment of epilepsy: the evidence to date

INTRODUCTION

Dysregulated mechanistic target of rapamycin (mTOR) activity is implicated in seizure development in epilepsies caused by variants in mTOR pathway genes. Sirolimus and everolimus, allosteric mTOR inhibitors, are widely used in transplant medicine and oncology. Everolimus is approved for treating seizures in tuberous sclerosis complex (TSC), the prototype mTORopathy. Emerging evidence suggests that mTOR inhibitors could also be effective in other mTORopathies, such as DEPDC5-related epilepsy and focal cortical dysplasia type 2 (FCD2).

AREAS COVERED

This narrative review summarizes key regulatory proteins in the mTOR cascade and outlines epilepsy syndromes linked to variants in genes encoding these proteins, particularly TSC, GATOR1-related epilepsies, and FCD2. It discusses the clinical pharmacology of mTOR inhibitors and the evidence supporting their efficacy as antiseizure medications (ASM) in mTORopathies. Lastly, potential benefits of next-generation mTOR inhibitors for CNS indications are evaluated.

EXPERT OPINION

The therapeutic benefits of mTOR inhibitors in TSC are well-established, but their value in other mTORopathies remains uncertain. Despite targeting the underlying disease biology, their efficacy in TSC is not significantly different from other ASM, likely due in part to pharmacokinetic constraints. Next-generation mTOR inhibitors that address these limitations may offer improved response rates, but they are in the preclinical development phase.

Subependymal Giant Cell Astrocytoma: The Molecular Landscape and Treatment Advances

Subependymal giant cell astrocytoma (SEGA) is most often found in patients with TSC (Tuberous Sclerosis Complex). Although it has been classified as a benign tumor, it may create a serious medical problem leading to grave consequences, including young patient demise. Surgery and chemotherapy belong to the gold standard of treatment. A broader pharmacological approach involves the ever-growing number of rapalogs and ATP-competitive inhibitors, as well as compounds targeting other kinases, such as dual PI3K/mTOR inhibitors and CK2 kinase inhibitors. Novel approaches may utilize noncoding RNA-based therapeutics and are extensively investigated to this end. The purpose of our review was to characterize SEGA and discuss the latest trends in the diagnosis and therapy of this disease.