Tonix Pharmaceuticals Reports Positive Pre-IND Meeting With FDA On TNX-102 SL, Advancing Plans To Treat Major Depressive Disorder

Tonix Pharmaceuticals Holding Corp., a fully integrated biotechnology company with marketed products and a development pipeline, announced the successful completion of a Type B Pre-Investigational New Drug meeting with the U.S. Food and Drug Administration regarding the development of TNX-102 SL (sublingual cyclobenzaprine HCl) for the treatment of major depressive disorder. The company received positive feedback from the FDA and intends to pursue a supplemental new drug application to expand the therapeutic use of TNX-102 SL to include major depressive disorder. This decision is based on exploratory findings suggesting that improving sleep quality may help reduce depressive symptoms.

Seth Lederman, M.D., chief executive officer of Tonix Pharmaceuticals, said the company is pleased with the outcome of the meeting and appreciates the FDA’s guidance, noting that this represents an important step toward developing TNX-102 SL as a new treatment option for major depressive disorder, a condition that affects millions of people and is not always effectively addressed by current therapies. Gregory Sullivan, M.D., chief medical officer of Tonix Pharmaceuticals, explained that bedtime administration of TNX-102 SL may offer a first-in-class approach by targeting the reduced slow wave sleep often seen in depression. 

He added that TNX-102 SL is a tertiary amine tricyclic designed for transmucosal absorption to bypass first-pass liver metabolism, unlike FDA-approved tertiary amine tricyclic antidepressants that are taken as pills and metabolized into secondary amine tricyclics. He further noted that existing tertiary amine tricyclic antidepressants require more than ten times the dosage used for TNX-102 SL and can negatively affect weight, blood pressure, cognition, and sexual function.

The FDA’s constructive feedback during the meeting included support for the proposed long-term safety data collection plan, which may help streamline the development pathway. Tonix plans to file an investigational new drug application in the fourth quarter of 2025, with Phase 2 clinical trials expected to follow shortly afterward. TNX-102 SL is already FDA-approved for fibromyalgia under the brand name Tonmya. 

In the Phase 3 RESILIENT study in fibromyalgia patients, TNX-102 SL showed an improvement in depressive symptoms over placebo as measured by the Beck Depression Inventory, achieving an uncorrected p-value of less than 0.05. Although the biological connection between depression in fibromyalgia and major depressive disorder remains unclear, these findings support further investigation of TNX-102 SL for this new indication.