Tonix ends 16-year hiatus in fibromyalgia treatment

Tonix Pharma is preparing to launch the first new therapy for fibromyalgia in the US in 16 years, after claiming FDA approval for Tonmya, an oral drug used to treat the pain associated with the condition.

Tonmya – a new under-the-tongue formulation of well-established muscle relaxant cyclobenzaprine HCl – has been cleared to treat adults with fibromyalgia, a common condition causing chronic pain, fatigue, poor sleep, and cognitive dysfunction that is estimated to affect more than 10 million people in the US. It mostly affects women.

Tonix is planning to launch Tonmya in the fourth quarter of this year as a once-daily analgesic designed to be taken at bedtime, and it is the first drug in its class to be approved for fibromyalgia.

The FDA approval came too late on Friday to affect Tonix's share price, but the stock was up nearly 13% in pre-market trading today. Some analysts have suggested that the drug could reach peak sales of $800 million or more, depending on its pricing, according to a Reuters report.

The company hasn't revealed its pricing plans yet, but the sales estimates are based on a modest premium to current drugs used to treat fibromyalgia, such as Pfizer's Lyrica (pregabalin), Eli Lilly's Cymbalta (duloxetine), and AbbVie's Savella (milnacipran), which dominate the market and cost around $150 to $200 per month. Savella was the last therapy to be approved by the FDA for fibromyalgia in 2009.

Tonix is holding an investor call later today, at which its pricing and commercial plans may be revealed. The company has prepared for the launch of Tonmya by acquiring two sumatriptan-based drugs (Zembrace SymTouch and Tosymra) for migraine – another pain-related condition that affects more women than men – from Upsher-Smith in 2023.

The two drugs bring in modest revenues of around $2 million a quarter, but buying them has allowed Tonix to build a women's health-focused sales operation in anticipation of Tonmya's approval.

Tonmya's approval comes on the back of two phase 3 trials (RELIEF and RESILIENT) involving nearly 1,000 patients, which showed a significant reduction in daily pain scores compared to placebo at 14 weeks, as well as an increase in the proportion of patients achieving a 30% or better improvement.

Its sublingual route of administration means that it bypasses first-pass metabolism in the liver, differentiating it from traditional oral formulations of cyclobenzaprine that are metabolised primarily in the liver and can cause side effects like confusion, unsteadiness, and fainting.

Tonix chief executive Seth Lederman said the approval is "a landmark advancement for the millions of people in the U.S. suffering from the debilitating pain this condition causes."

Meanwhile, rheumatology specialist Philip Mease of the University of Washington School of Medicine said that fibromyalgia currently has limited options that do not adequately meet treatment needs for the majority of patients, adding: "Tonmya is a novel treatment approach that targets nonrestorative sleep that is characteristic of fibromyalgia and can impact core symptoms, specifically pain."

Photo by Yuris Alhumaydy on Unsplash