Cyclerion Advances Novel EEG-Guided Depression Therapy

CAMBRIDGE, Mass. – February 17, 2026 – Cyclerion Therapeutics has announced significant progress in its mission to tackle one of mental health's most formidable challenges, receiving positive feedback from the U.S. Food and Drug Administration (FDA) for its novel treatment for treatment-resistant depression (TRD). The biopharmaceutical company also unveiled a newly formed Clinical Advisory Board stacked with world-renowned experts, signaling a major step forward for its lead candidate, CYC-126.

The developments provide a clearer regulatory pathway and a powerful injection of clinical expertise for a therapy that aims to redefine precision in neuropsychiatry. CYC-126 is an investigational, anesthetic-based therapy that uniquely incorporates real-time electroencephalogram (EEG) feedback to guide treatment, a departure from conventional approaches.

A New Frontier in Precision Psychiatry

At the heart of Cyclerion's strategy is a sophisticated fusion of pharmacology and technology. CYC-126 combines well-characterized anesthetic agents with real-time EEG monitoring and an algorithm-guided dosing system. The goal is to precisely navigate a patient's brain activity into a targeted state associated with antidepressant effects, a process the company believes can recalibrate dysfunctional neural networks.

This method stands in contrast to other anesthetic-based treatments for depression, such as ketamine. While ketamine and its derivative, esketamine (Spravato), have proven to be rapid-acting and effective for many, CYC-126’s innovation lies in its individualized control. By using EEG to continuously monitor brain waves, clinicians can theoretically maintain a specific therapeutic state with greater accuracy, potentially overcoming the variability seen in other treatments and enhancing both efficacy and durability of the response.

The approach builds on established principles. EEG-guided anesthesia is already used in surgical settings to optimize sedation depth and reduce postoperative complications like delirium. Cyclerion is now pioneering its application for neuropsychiatric disorders, aiming to create a treatment that is not only rapid-acting but also personalized. The planned regimen involves an induction phase of three sessions per week for three weeks, followed by a less frequent maintenance phase, possibly with once-monthly dosing.

Navigating the Regulatory Path

The recent written feedback from the FDA marks a critical de-risking milestone for Cyclerion. The agency provided clarity on the regulatory jurisdiction for CYC-126, which, as a drug-device combination product, will be primarily regulated by the Center for Drug Evaluation and Research (CDER), with input from the Center for Devices and Radiologic Health (CDRH). This alignment affirms the company's development strategy and provides a clear roadmap for its upcoming Investigational New Drug (IND) submission.

“We are pleased with the constructive feedback received from the FDA, which provides additional clarity regarding CYC-126’s regulatory jurisdiction and development pathway,” said Regina Graul, Ph.D., President and Chief Executive Officer of Cyclerion. “This alignment supports our IND planning and affirms key elements of our proposed Phase 2 study design. We value the ongoing engagement with the applicable FDA divisions and believe this guidance provides an important foundation as we advance CYC-126 with the goal of addressing the significant unmet need in patients living with TRD.”

The company's planned Phase 2 proof-of-concept study is a randomized, double-blind trial that will evaluate the safety, efficacy, and durability of CYC-126 against a sham control in adults with TRD. Efficacy will be measured using established clinical endpoints, including the Montgomery–Åsberg Depression Rating Scale (MADRS). By leveraging FDA-approved anesthetics with extensive safety data, Cyclerion can streamline parts of its development program. The company remains on track to initiate the study in the second half of 2026, with enrollment beginning in Australia, followed by U.S. sites in the first half of 2027.

Assembling an Expert Powerhouse

Bolstering its scientific and clinical credibility, Cyclerion has formed a Clinical Advisory Board (CAB) composed of five internationally recognized leaders. The board’s collective expertise spans neuropsychiatry, anesthesiology, clinical development, and medical device innovation, creating a formidable brain trust to guide CYC-126.

Notable appointees include Dr. Husseini Manji, a global leader in neuroscience who, during his tenure at Janssen, was instrumental in the development of the groundbreaking TRD treatment Spravato. His experience brings invaluable insight into navigating the complexities of developing and launching novel psychiatric therapies. He is joined by Dr. Linda Carpenter, a leading expert in neurostimulation techniques like TMS and deep brain stimulation, whose work at Brown University and Butler Hospital focuses on the very patient population Cyclerion aims to treat.

The board also includes Dr. Lawrence Olanoff, a seasoned pharmaceutical executive with a track record of contributing to thirty new drug approvals; Dr. Yuriy Bronshteyn, an anesthesiologist and intensivist from Duke University with deep expertise in critical care and ultrasound; and Dr. Laeben C. Lester, a cardiac anesthesiologist and medical device innovator from Johns Hopkins Medicine.

“We are honored to welcome this distinguished group of clinical experts to our Clinical Advisory Board,” Graul stated. “These accomplished leaders bring a powerful combination of neuropsychiatric, anesthesiology, and clinical development expertise that will help guide the advancement of CYC-126 and inform the continued expansion of our pipeline.”

The High Stakes of Treatment-Resistant Depression

The push for innovative therapies like CYC-126 is driven by a profound unmet need. Treatment-resistant depression affects roughly one-third of the millions of people diagnosed with major depressive disorder, leaving them in a debilitating cycle of ineffective treatments. For this population, the failure of at least two standard antidepressants creates a desperate need for new options that can offer rapid and lasting relief.

For Cyclerion, the stakes are equally high. The company has identified CYC-126 as its foundational asset and the cornerstone of its future growth. As noted in past SEC filings, the company faces financial pressures common in the biotech industry, making the successful development of its lead candidate paramount. The positive FDA feedback and the formation of a world-class advisory board provide crucial momentum as the company moves toward its pivotal Phase 2 study. With a clear path forward, Cyclerion is poised to test whether its precision-medicine approach can deliver new hope for one of medicine’s most challenging conditions.