By Pat Anson, PNN Editor

New Jersey-based Tonix Pharmaceuticals says it will proceed with a Phase 3 study of a drug to treat fibromyalgia, despite disappointing results that caused the company to stop enrolling new patients.

Based on an interim analysis of the first 337 participants enrolled in the RALLY study, an independent data monitoring committee found that TNX-102 SL was unlikely to demonstrate a statistically significant improvement in pain compared to placebo. No issues were reported on the safety of the drug.

The finding of the monitoring committee is somewhat surprising, because Tonix recently reported results from another Phase 3 study, which found that TNX-102 SL significantly reduced pain compared to placebo and also improved sleep, fatigue and function in fibromyalgia patients.

“We are surprised and disappointed that the interim analysis did not support continued enrollment in this Phase 3 RALLY study, especially considering the previous Phase 3 RELIEF study, which had a similar design and achieved statistical significance on the primary endpoint,” said Seth Lederman, MD, President and CEO of Tonix. “These results underscore the difficulty in managing and treating fibromyalgia.”

Lederman said the company would continue its Phase 3 trial with the patients who are already enrolled and report the results in the fourth quarter of 2021. It will then determine its next steps.

TNX-102 SL is a sublingual tablet formulation of cyclobenzaprine hydrochloride, a muscle relaxant and anti-depressant that’s being evaluated as a daily bedtime treatment for fibromyalgia. The goal is to see if TNX-102 SL helps fibromyalgia patients sleep better.  In addition to fibromyalgia, TNX-102 SL is also being considered as a treatment for post-traumatic stress disorder (PTSD), alcohol use disorder and agitation in Alzheimer’s disease.

Fibromyalgia is a poorly understood disorder characterized by widespread body pain, fatigue, poor sleep and depression. The National Institutes of Health estimates about 5 million Americans have fibromyalgia. Most people diagnosed with fibromyalgia are women, although men and children can also be affected.

The FDA has approved only three drugs to treat fibromyalgia; the antidepressants duloxetine (Cymbalta) and milnacipran (Savella), and the anti-seizure medication pregabalin (Lyrica). Many fibromyalgia patients say the drugs are ineffective and have unwelcome side effects. A recent analysis found little evidence to support the long-term use of any medication or therapy to treat fibromyalgia.