Key Highlights

  • New Program: ET-900 targets mecasermin for infantile and epileptic spasms, a rare and often treatment-resistant seizure condition
  • License Agreement: Eton has licensed Patent rights from Baylor College of Medicine covering IGF-1's use in this indication
  • Preclinical Data: Animal studies funded by CURE Epilepsy showed a roughly 50% reduction in daily spasm counts, with spasms eliminated entirely in 20% of treated animals
  • Phase 2 Trial: An IND has been submitted for an investigator-sponsored study enrolling up to 20 pediatric patients across three academic medical centers, with first dosing targeted for Q1 2027

Eton Pharmaceuticals(NASDAQ:ETON), a Deer Park, Illinois-based specialty pharmaceutical company focused on rare diseases, announced on November 2, 2026, the launch of ET-900, a new development program evaluating mecasermin injection as a potential treatment for infantile and epileptic spasms. The program builds on Eton's existing commercial Franchise around mecasermin — which it already markets in the United States as INCRELEX for a different indication — and expands its ambitions into the pediatric neurology space.

The Science Behind ET-900

Mecasermin is a recombinant form of insulin-like growth Factor 1 (IGF-1), a naturally occurring protein involved in growth and neurological development. Eton's hypothesis, derived from research led by Dr. John W. Swann at Baylor College of Medicine, is that impaired IGF-1 signaling in the brain may be a contributing factor in the development of epileptic spasms — a hypothesis that opens the possibility of using mecasermin as a replacement therapy to restore normal brain activity in affected children.

The preclinical research, funded by CURE Epilepsy and the National Institutes of Health, was conducted in animal models. Treatment with recombinant human IGF-1 reduced daily spasm counts by approximately 50% and eliminated spasms entirely in 20% of treated animals. Additional studies showed that patients with structural brain abnormalities — a common feature in children with infantile spasms — have reduced IGF-1 levels in their brains, lending further support to the replacement therapy concept.

"The Baylor research provides a compelling scientific rationale for evaluating IGF-1 therapy for use with this condition," said Sean Brynjelsen, Chief Executive Officer of Eton Pharmaceuticals. "With an IND now submitted, we are excited to help translate this research into meaningful clinical advancement."

Eton has entered into a license agreement with Baylor College of Medicine covering patent rights related to the use of IGF-1 for treating spasms, providing a legal foundation for its commercial rights to ET-900.

The Planned Clinical Trial

An Investigational New Drug application has been submitted to the U.S. Food and Drug Administration for an investigator-sponsored Phase 2 study. The trial will be sponsored by the University of Chicago and is expected to enroll up to 20 patients between two and 18 years of age at three sites: the University of Chicago, Baylor College of Medicine, and UCLA. Eligible patients will have spasms that have not responded to, or that they could not tolerate, standard first-line therapies including hormonal treatment and vigabatrin.

Enrolled patients will receive twice-daily subcutaneous injections of mecasermin during an initial three- to five-week treatment period. Additional treatment may be available to certain patients based on clinical response. The study will measure spasm resolution, changes in daily spasm frequency, and improvement in electroencephalogram abnormalities. Safety, tolerability, and adaptive functioning will also be assessed. Initial dosing is targeted for the first quarter of 2027.

Mecasermin is not currently FDA-approved for the treatment of infantile or epileptic spasms, and its safety and efficacy for these uses have not been established.

Risks

ET-900 is at an early clinical stage, and Phase 2 trials — particularly in rare pediatric diseases with small patient populations — carry substantial uncertainty. Positive preclinical findings in animal models do not reliably predict outcomes in human trials. Even if the Phase 2 results are favorable, further development would require a larger controlled trial, continued regulatory review, and ultimately FDA approval before any commercial sale could occur.

Eton's existing INCRELEX product, which provides the commercial foundation for this program, is already approved and marketed for a different condition. Extending it into a new indication requires demonstrating safety and efficacy separately, and any adverse findings in the ET-900 study could potentially create reputational or regulatory spillover effects for INCRELEX.

The small trial enrollment of up to 20 patients limits the statistical power of the Phase 2 study, meaning results may be directional rather than definitive. Larger follow-on studies would be required to characterize the treatment effect with confidence.

What to Watch Next

First patient dosing in Q1 2027 will be the immediate milestone to watch. Any updates on IND clearance by the FDA — which has 30 days to review an IND before trials can begin — will precede that. Interim data readouts or congress presentations by the investigator team at the University of Chicago would also represent important progress signals.

Longer term, whether Eton elects to pursue full sponsorship of a pivotal trial, or whether it licenses ET-900 to a larger pharmaceutical partner, will indicate how the company assesses the program's commercial potential relative to its Balance Sheet capacity.

Sector Context

Infantile epileptic spasms syndrome affects approximately 2,500 children annually in the United States and remains challenging to treat. Roughly half of affected children do not achieve adequate seizure control with initial therapies, a treatment gap that creates genuine medical need. The rare disease designation would, if granted, provide Eton with potential regulatory incentives including Orphan Drug exclusivity and expedited review pathways.

The application of IGF-1 to neurological conditions reflects a broader interest in neuroprotective and neurodevelopmental mechanisms as targets for drug development. Research in this area has been funded by disease advocacy organizations like CURE Epilepsy for more than a decade, and Eton's entry into the space represents a step toward commercializing that scientific investment.