The U.S. Food and Drug Administration (FDA) has approved cyclobenzaprine HCl sublingual tablets (Tonmya, Tonix Pharmaceuticals) for the treatment of fibromyalgia in adults. Tonmya is a first-in-class, non-opioid, once-daily bedtime treatment designed for rapid absorption via a sublingual formulation.
Approval was based on results from two double-blind, randomized, placebo-controlled, Phase 3 clinical trials that evaluated cyclobenzaprine as a bedtime treatment for fibromyalgia. This included the RESILIENT study, where Patients (n=456) were randomized 1:1 to receive cyclobenzaprine 2.8 mg nightly for 2 weeks, followed by 5.6 mg for 12 weeks, or matching placebo. The primary endpoint was change from baseline in the weekly average of daily diary pain intensity scores at week 14. cyclobenzaprine demonstrated statistically significant improvement in pain scores compared to placebo (mean change: -1.8 vs -1.2; SE = 0.12; P < .001).
All six secondary endpoints were also significantly improved with cyclobenzaprine versus placebo (P = .001). The treatment completion rate was 81.0 percent in the cyclobenzaprine group and 79.6 percent in the placebo group and cyclobenzaprine was generally well tolerated. The most common adverse events (incidence =2% and at a higher incidence in cyclobenzaprine-treated patients compared to placebo-treated patients) included oral hypoesthesia (numbness in the mouth), oral discomfort, abnormal product taste, somnolence (drowsiness), oral paresthesia (tingling, pricking or burning in the mouth), oral pain, fatigue, dry mouth, and aphthous ulcer (canker sore).
Cyclobenzaprine significantly improved pain, function, and sleep-related outcomes in patients with fibromyalgia and was well tolerated. Its approval represents the first new FDA-approved treatment for fibromyalgia in over 15 years.