Filana Therapeutics clears FDA hold on simufilam for TSC epilepsy
Filana Therapeutics has received confirmation that the US Food and Drug Administration has lifted the clinical hold on its investigational new drug application for simufilam, an oral small molecule targeting the filamin A protein. The clearance opens the path to a Phase 2a proof-of-concept study in patients aged 12 to 55 with tuberous sclerosis complex (TSC)-related epilepsy, with patient screening expected to begin by the first quarter of 2027.
The Austin, Texas-based company said it used the hold period productively, engaging a clinical research organisation, identifying trial sites, and recruiting potential investigators. Rick Barry, President and Chief Executive Officer of Filana, said the company now intends to "progress expeditiously toward site initiation and patient enrolment," with investigational drug supply already in place.
Trial design and scientific rationale
The Phase 2a study is designed as a 16-week, multicenter, randomised, double-blind trial evaluating two doses of simufilam in patients with refractory TSC-related seizures. Forty subjects will be enrolled across 13 US sites. All participants who complete the double-blind phase are eligible for a 48-week open-label extension. Primary assessments will cover safety, tolerability, and pharmacokinetics, alongside seizure frequency, intensity, duration, nighttime seizures, and sleep-related outcomes. The company said data from the study will help inform the design of future trials in younger patient populations.
The scientific basis for the programme rests on two preclinical studies. Research conducted in the laboratory of Angélique Bordey, who holds a joint role as Rothberg Professor of Neurosurgery at Yale School of Medicine and Senior Vice President of Neuroscience at Filana, showed that simufilam reduced seizure frequency in a mouse model of focal onset seizures linked to TSC pathology. A second study, carried out with the TSC Alliance Preclinical Consortium using a TSC-knockout mouse model, demonstrated dose-dependent attenuation of seizure progression. Filana holds an exclusive worldwide licence from Yale University to the underlying intellectual property.
Market context and unmet need
TSC is a rare genetic disorder caused by mutations in the TSC1 or TSC2 genes, which disrupt the mTOR signalling pathway and drive tumour growth across multiple organs. Epilepsy is the most prevalent complication, affecting an estimated 80 to 90 per cent of TSC patients. Around 45,000 people in the US live with TSC-related epilepsy, and despite a range of approved antiepileptic agents, more than 60 per cent of patients remain refractory to existing therapy. That persistent treatment gap is the commercial and clinical rationale Filana is leaning on.
The TSC epilepsy space has attracted several investigational approaches targeting the mTOR pathway, most notably everolimus, which holds regulatory approval for TSC-related seizures in some markets. Simufilam's differentiation lies in its filamin A mechanism, which sits outside the established mTOR inhibitor class and could in principle provide additional seizure control in patients who have already failed mTOR-directed therapy. Whether preclinical signal translates to meaningful clinical benefit in a 40-patient proof-of-concept study will be the critical question investors and clinicians watch for. With patient screening roughly two quarters away, a first readout on safety and seizure measures is unlikely before late 2028 given the 16-week treatment period and extension study timelines.
The TSC Alliance, a US patient advocacy organisation, is collaborating with Filana on patient engagement and study execution, and its chief executive Kari Luther Rosbeck welcomed the trial's launch, citing the potential for a new mechanism to address a "major unmet need" for the community.