Press Release

Neurona Therapeutics Presents New Clinical Data from First Cohort in Ongoing Phase I/II Open-Label Trial of NRTX-1001 Cell Therapy for Drug-resistant Mesial Temporal Lobe Epilepsy (MTLE)

– NRTX-1001 investigational treatment has been well tolerated in all initial subjects

– Positive decision from data safety monitoring board (DSMB) on review of first cohort safety data greenlights dosing of five additional subjects in the second, highest dose, cohort

– First two subjects continue to report a >95% reduction in overall average monthly seizure counts one year after treatment

– Early clinical data will be presented at the Annual Meeting of the American Epilepsy Society

San Francisco, CA, December 1, 2023 Neurona Therapeutics, a clinical-stage biotherapeutics company advancing regenerative cell therapy candidates for the treatment of neurological disorders, announced presentation of positive preliminary clinical data from the first cohort of five subjects in its ongoing open-label, single-arm Phase I/II clinical trial of NRTX-1001, an investigational allogeneic cell therapy candidate that is being developed for treatment of drug-resistant MTLE. The data will be presented at the Annual Meeting of the American Epilepsy Society, which is being held December 1-5, 2023 in Orlando, Florida.

Separately, the Data Safety Monitoring Board (DSMB) overseeing the Phase I/II trial cleared continuing enrollment for another five patients who will receive a one-time administration of the higher dose level of NRTX-1001.

“The DSMB’s decision to allow the enrollment of five more subjects in our ongoing open-label Phase I/II clinical trial is a testament to NRTX-1001 being well-tolerated in the first cohort,” said Cory R. Nicholas, Ph.D., Neurona’s chief executive officer. “The early data from the first cohort in the trial have been very encouraging, with substantial, durable seizure reduction in the first subjects with drug-resistant MTLE. We look forward to advancing the development of NRTX-1001 cell therapy with our top-dose cohort of five subjects now enrolling into early 2024.”

The five subjects in the first cohort received a one-time administration of NRTX-1001 as well as immunosuppression administered over the first year, which is intended to promote the long-term persistence of NRTX-1001. All subjects who received NRTX-1001 in the ongoing clinical trial entered the study with a history of significant monthly seizure activity that was not controlled by anti-seizure medications. The first two subjects continue to report a >95% reduction from baseline in overall seizure counts more than one year after NRTX-1001 administration. The first subject had a baseline seizure frequency of 32 seizures per month, is now 17 months into the study, and has reported no focal impaired awareness seizures since the first month post-treatment. The second subject had a baseline seizure frequency of 14 seizures per month, is now at the 12-month mark, and has not had a focal impaired awareness seizure in the past six months. The first subject in the clinical trial underwent a tapered discontinuation of the immunosuppression regimen at one-year post-treatment and continues to show >95% stable seizure reduction 17 months from cell administration. The second subject in the clinical trial is tapering off the immunosuppression. No antibodies to the NRTX-1001 cells have been detected in either of the first two subjects. Per protocol, modality-specific cognitive tests administered at six months post-treatment, and subsequently at three-month intervals thereafter, revealed improvements in some measures, and no deterioration, in the first and second subjects.

Early data will also be presented from the next three subjects who were treated with NRTX-1001 in July-August 2023. Two of the three subjects have demonstrated reduction in their average total seizure activity since treatment. The third subject had 26 seizures per month at baseline, is three months into the study, has had a 64% reduction of focal aware events, and has not reported any focal impaired awareness events or seizures with objective manifestation since treatment. The fifth subject had 30 seizures per month at baseline, is also three months into the study, and has reported a 75% reduction in both focal aware and focal impaired awareness seizures to date. The fourth subject, who entered the trial with baseline seizure activity of two seizures per month, continues to experience a variability in seizure count that is consistent with their disease history. Of note, in preclinical in vivo studies in a model of MTLE, maximum efficacy of NRTX-1001 required up to five to seven months from administration to become apparent, reflecting the time taken for the transplanted cells to functionally integrate and mature.

NRTX-1001 has been well-tolerated in all subjects to date. Adverse events have been mild to moderate and typical of those associated with the immunosuppression regimen. No severe adverse events from the cell therapy, delivery procedure, or immunosuppression regimen have been reported thus far in the ongoing clinical trial. One subject in the first cohort had a serious adverse event of a focal to bilateral tonic-clonic cluster of seizures (status epilepticus) that was deemed not related to cell treatment, delivery procedure, or immunosuppression. This subject has a prior history of similar episodes and is in stable condition.

“Neurona’s regenerative cell therapy approach has the potential to provide a single-administration, non-destructive alternative for the treatment of drug-resistant MTLE,” said David Blum, M.D., Neurona’s chief medical officer. “Currently, people with MTLE who are not responsive to anti-seizure medications have limited options, such as an invasive surgery that removes or destroys the affected brain tissue. FDA approval of novel tissue- and memory-sparing approaches could be transformative for such patients.”

About Neurona’s Clinical Trial of NRTX-1001 for Drug-Resistant Mesial Temporal Lobe Epilepsy (MTLE)

The clinical study is designed to evaluate the safety and efficacy of a single administration of NRTX-1001 for drug-resistant MTLE. The first stage of the trial is an open-label dose-escalation study in up to 10 people with drug-resistant MTLE, with five subjects in the first cohort treated at a starting dose and five subjects in the second cohort to be treated at a higher dose. Subjects treated with a single infusion of NRTX-1001 cells will be monitored for safety and effects on their epilepsy disease symptoms. Subject recruitment is underway at epilepsy centers across the United States. For more information, please visit (NCT05135091). The first part of the clinical trial is supported by an $8.0 million grant from the California Institute for Regenerative Medicine (CIRM; CLIN2-13355). With $5.5 billion in funding and more than 150 active stem cell programs in its portfolio, CIRM is one of the world’s largest institutions dedicated to helping people by bringing the future of cellular medicine closer to reality.

About NRTX-1001

NRTX-1001 is a regenerative neural cell therapy candidate derived from human pluripotent stem cells. The fully-differentiated neural cells, called interneurons, secrete the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). Delivered as a one-time dose, the human interneurons are intended to integrate and innervate on-target neural circuits and are designed to durably silence seizure activity in the epileptic region of the brain. NRTX-1001 is manufactured in Neurona’s in-house GMP facility using proprietary methods. 

About Mesial Temporal Lobe Epilepsy 

According to the Centers for Disease Control and Prevention, an estimated 3.4 million Americans have epilepsy, and 25 to 35 percent live with ongoing seizures despite treatment with approved drugs, illustrating a substantial unmet medical need in this community. MTLE is a common type of focal epilepsy in adults and primarily affects the internal structures of the temporal lobe, where seizures often begin in a structure called the hippocampus. For people with seizures resistant to anti-seizure drugs, epilepsy surgery - where the damaged temporal lobe is surgically removed or ablated by laser - can be an option. However, the current surgical options are not available or effective for all subjects, are tissue-destructive, and can have significant adverse effects.

About Neurona Therapeutics

Neurona is focused on developing regenerative cell therapy candidates with single-dose curative potential. Neurona’s investigational allogeneic neural cell therapy candidates are designed to provide long-term repair of dysfunctional neural networks for multiple neurological disorders. For more information about Neurona, visit

Forward-Looking Statements

This press release includes forward-looking statements subject to risks and uncertainties, including risks and uncertainties inherent in the clinical development of therapeutic candidates, risks that early data collected from a small number of subjects may not be predictive of data when NRTX-1001 is tested in larger clinical trials, the possibility that timelines may change, and difficulties associated with obtaining sufficient data to demonstrate safety and efficacy to support regulatory approval. NRTX-1001 is an investigational candidate and is being evaluated in ongoing clinical trials. NRTX-1001 has not been approved by any regulatory authority for commercial use or deemed to be safe or effective for any indication.

Investor and Media Contacts:

Sylvia Wheeler
Wheelhouse LSA

Elizabeth Wolffe, Ph.D.
Wheelhouse LSA