Sublingual Cyclobenzaprine improves pain control in fibromyalgia patients

A new study published in Arthritis Care & Research showed that treatment with TNX-102 SL was linked with substantial decreases in daily pain and was safe and well tolerated in a phase 3 randomized, controlled study of fibromyalgia patients.

For many years, cyclobenzaprine in the form of regular pills has been proposed as a viable treatment for fibromyalgia pain, but thorough research has not clearly shown a benefit. The majority of the "no evidence" for fibromyalgia pain alleviation was discovered in a study written for the Agency for Healthcare Research and Quality in 2020. In order to assess the effectiveness and safety of TNX-102 SL, a once-daily sublingual formulation of cyclobenzaprine, in relieving pain in individuals with fibromyalgia, Seth Lederman and colleagues conducted this study.

The RELIEF trial was a randomized, double-blind, placebo-controlled study. Overall, 503 patients received matched placebo (255 patients), TNX-102 SL 2.8 mg for 2 weeks, then 5.6 mg for 12 weeks. The weekly average of daily pain ratings at week 14 were the main goal. The Patient-Reported Outcomes Measurement Information System (PROMIS) Sleep Disturbance and Fatigue scores, Patient Global Impression of Change (PGIC) scores, Fibromyalgia Impact Questionnaire Revised (FIQR) scores, and daily sleep quality were used as secondary endpoints. Adverse occurrences (AEs) were used to evaluate safety.

The key findings of this study were:

TNX-102 SL significantly reduced daily pain from baseline at week 14 compared to placebo.

At week 14, PGIC did not significantly improve as a result of TNX-102 SL, although there was an improvement in FIQR, PROMIS, and daily sleep quality.

Mouth hypoesthesia, mouth paresthesia, and altered product taste were the most frequently reported treatment-emergent adverse events (AEs) in patients receiving TNX-102 SL and 46.3% in patients receiving placebo.

Patients with fibromyalgia wanting to find a more practical and efficient version of cyclobenzaprine at their neighborhood pharmacies must wait for the third and current phase III study of the drug to be completed, since the prior two produced conflicting findings.

Reference:

Lederman, S., Arnold, L. M., Vaughn, B., Kelley, M., & Sullivan, G. M. (2023). Efficacy and Safety of TNX ‐102 SL (Sublingual Cyclobenzaprine) for the Treatment of Fibromyalgia: Results From the Randomized, Placebo‐Controlled RELIEF Trial. In Arthritis Care & Research. Wiley. https://doi.org/10.1002/acr.25142