Tonix Pharmaceuticals said today it will end development of TNX-102 SL (cyclobenzaprine HCl sublingual tablets) for fibromyalgia following its failure in a Phase III trial—but continue developing the candidate for posttraumatic stress disorder (PTSD).
Tonix said TNX-102 SL, taken once-daily at a 2.8-mg dosage, missed its primary efficacy endpoint in the AFFIRM trial, according to preliminary topline results. TNX-102 SL did not achieve a statistically significant proportion of patients reporting a 30% or greater reduction in pain from baseline to the end of the trial’s 12-week treatment period, Tonix acknowledged.
TNX-102 SL did show statistically significant effects on pain, however, at two additional endpoints—Patient Global Impression of Change and Fibromyalgia Impact Questionnaire-Revised—during AFFIRM. This was a 12-week randomized, double-blind, placebo-controlled trial of TNX-102 SL taken daily at bedtime, in which 519 participants were enrolled at 35 centers in the U.S.
“Despite achieving clinically meaningful results from AFFIRM, we have greater clarity on the regulatory path forward in our PTSD program. We will therefore discontinue the fibromyalgia program in order to fully focus Tonix’s resources on advancing our potential breakthrough PTSD program to Phase III,” Tonix President and CEO Seth Lederman, M.D., said in a statement.
Tonix received FDA acceptance last month for its Phase III clinical program for TNX-102 SL in PTSD, to consist of a military-related PTSD trial set to start in the first quarter of 2017 and a civilian-related PTSD trial set to start in the second quarter.
In May, the company reported positive Phase II results in May from a Phase II trial of TNX-102 SL in PTSD, including reduction in symptoms and disease severity.
“We owe it to our investors, and to patients who are waiting for meaningful clinical innovation, to steward our resources effectively,” Dr. Lederman added.
Tonix has sought to reformulate cyclobenzaprine, an FDA-approved muscle relaxant, to treat fibromyalgia and PTSD, by moving absorption up 1 hour and developing a sublingual (under the tongue) delivery mechanism.
TNX-102 SL is designed to deliver cyclobenzaprine to the bloodstream rapidly via sublingual absorption and to bypass first-pass hepatic metabolism. A multifunctional agent with antagonist activities at the serotonin-2A, alpha-1 adrenergic, and histamine H1 receptors, TNX-102 SL will continue under clinical development at a 5.6-mg dosage for daily bedtime administration for PTSD.
According to Tonix, TNX-102 SL is intended to provide broad spectrum improvement by targeting sleep quality and the stress response.