Tonix Pharmaceuticals Wins FDA IND Clearance To Advance TNX-102 SL For Phase 2 HORIZON Study, Targeting Unmet Needs In Major Depressive Disorder

Tonix Pharmaceuticals Holding Corp., announced that the U.S. FDA has cleared its Investigational New Drug (IND) application for TNX-102 SL, a sublingual cyclobenzaprine formulation, for clinical evaluation as a potential treatment for major depressive disorder (MDD) in adults. This milestone allows the company to advance the program into its next stage of development.

“There is a clear need for innovative therapies that address depression,” said Seth Lederman, M.D., Chief Executive Officer of Tonix Pharmaceuticals. “We believe TNX-102 SL offers a promising approach for individuals suffering from MDD. The unique pharmacological profile of TNX-102 SL is designed to target the disruptive sleep which is often associated with depression. Prior studies of TNX-102 SL in fibromyalgia and post-traumatic stress disorder (PTSD) showed promising signals for improvement of depressive symptoms on the Beck Depression Inventory-II and the Montgomery-Asberg Depression Rating Scale (MADRS), respectively. We are excited to advance TNX-102 SL and look forward to evaluating its potential as a new treatment option for those affected by depression.”

With the IND approval, Tonix will begin preparations for the Phase 2 HORIZON trial, a potentially pivotal, 6-week, randomized, double-blind, placebo-controlled study investigating TNX-102 SL as a first-line monotherapy for MDD. The trial will enroll about 360 patients across roughly 30 U.S. clinical sites. The primary endpoint will assess changes in MADRS scores over a six-week period, with secondary measures evaluating global functioning, anxiety symptoms, and sleep-related outcomes. Enrollment is scheduled to begin in mid-2026.

“TNX-102 SL is designed to target the disturbed sleep of depression, which is a novel mechanism of action,” said Gregory Sullivan, M.D., Chief Medical Officer of Tonix Pharmaceuticals. “TNX-102 SL has been generally well tolerated in registrational studies of fibromyalgia patients. In the fibromyalgia studies, TNX-102 SL treatment was associated with a low incidence of side effects common with traditional antidepressants like weight gain, blood pressure changes, sexual dysfunction and cognitive issues.”

MDD remains one of the most common and debilitating mental health disorders, affecting over 21 million U.S. adults each year. Despite the availability of multiple antidepressants, many patients experience insufficient symptom relief or discontinue treatment due to tolerability issues. Persistent symptoms—such as low mood, loss of interest, fatigue, sleep disruption, and impaired cognition—can severely affect daily life and heighten suicide risk. The need for well-tolerated and effective first-line therapies remains a major unmet medical priority.