MOUNTAIN VIEW, Calif., July 28, 2026
NeuroPace announced that the U.S. Food and Drug Administration (FDA) has informed the company that its Premarket Approval (PMA) Panel Track Supplement seeking to expand the RNS® System indication to patients with drug-resistant idiopathic generalized epilepsy (IGE) is not approvable in its current form. The FDA has requested additional clinical evidence from the Phase 3 NAUTILUS trial, along with supporting scientific literature, before the submission can move forward. Following discussions with the Agency, NeuroPace confirmed it will submit a Submission Issue Request (SIR) to address the FDA’s remaining questions and plans to amend the application with supplemental data and additional context regarding the patient population evaluated in the NAUTILUS clinical trial. The company stated that while an initial approval was not received, it believes there is a clear regulatory pathway toward approval through continued collaboration with the FDA.
NAUTILUS Trial Demonstrates Strong Clinical Benefits
The PMA Supplement is supported by findings from the NAUTILUS study, the first randomized controlled trial evaluating responsive neuromodulation in patients with drug-resistant idiopathic generalized epilepsy. Published in Epilepsia in June 2026, the study provides Level 1 clinical evidence supporting responsive thalamic stimulation as a potential treatment for patients who currently have no approved neuromodulation or surgical treatment options. At 18 months, patients treated with the RNS System achieved a 77% median reduction in generalized tonic-clonic (GTC) seizures, while 40% experienced complete GTC seizure freedom. The study also demonstrated meaningful reductions in absence and myoclonic seizures, with more than 90% of patients reporting improvement on the Patient Global Impression of Change and 80% of physicians documenting clinical improvement. At the FDA’s request, NeuroPace also submitted 24-month follow-up data, showing continued therapeutic benefit, including a 100% median reduction in GTC seizures among evaluable patients receiving stimulation for 23 of 24 months, highlighting the therapy’s potential for durable long-term seizure control.
Company Remains Confident in Regulatory Approval Path
NeuroPace President and Chief Executive Officer Joel Becker stated that although the FDA did not approve the submission during the current review cycle, subsequent discussions with the Agency were encouraging and focused on identifying the information necessary to support approval. According to the company, the FDA has demonstrated a willingness to continue working collaboratively through the Submission Issue Request process, providing NeuroPace with an opportunity to strengthen its application using additional clinical evidence and scientific context. Dr. Martha Morrell, Chief Medical Officer of NeuroPace, emphasized that patients enrolled in the NAUTILUS trial had lived with uncontrolled generalized seizures for an average of more than 18 years while taking nearly four antiseizure medications daily, underscoring the substantial unmet medical need. She noted that patients with medically refractory IGE currently lack approved neuromodulation therapies, making the potential expansion of the RNS System particularly significant for this underserved patient population.
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Potential Expansion Could Broaden RNS System Impact
The proposed indication expansion represents an important opportunity for NeuroPace to extend the clinical application of its RNS System, currently the first and only commercially available brain-responsive neuromodulation platform delivering personalized, real-time treatment directly at the seizure source. If approved, the expanded indication would provide a novel treatment option for patients with drug-resistant idiopathic generalized epilepsy, a condition associated with significant risks of injury, diminished quality of life, and increased mortality due to uncontrolled seizures. While the company noted that its current financial guidance does not include revenue contributions from the potential indication expansion, NeuroPace remains focused on working closely with the FDA to complete the review process. Continued analysis of the NAUTILUS clinical data, together with additional evidence requested by regulators, could help support future approval and further establish responsive neuromodulation as an important therapeutic approach for patients with difficult-to-treat generalized epilepsy.
Source: NeuroPace press release
