P-036 - (Poster #36) Sublingual cyclobenzaprine (TNX-102 SL) for fibromyalgia: efficacy and safety in two randomized placebo-controlled trials

Fibromyalgia (FM) is a chronic pain disorder characterized by heightened sensory and pain signaling within the central nervous system (CNS). Affecting approximately 6 to 12 million U.S. adults, primarily women, FM causes widespread pain, nonrestorative sleep, fatigue, and cognitive dysfunction. TNX-102 SL, believed to target FM sleep disturbance, is a novel sublingual cyclobenzaprine tablet that significantly improved FM pain in two Phase 3 studies.

Purpose/Objectives: To report the efficacy via responder analysis and safety of TNX-102 SL in the treatment of FM from two Phase 3 randomized placebo-controlled trials (RELIEF and RESILIENT).

Methods:

Two randomized clinical trials assessed the efficacy and safety of TNX-102 SL. The primary endpoint in both studies was the change from baseline in weekly average of daily pain numeric rating scale scores at Week 14, analyzed using a mixed model for repeated measures with multiple imputation for missing data. In both studies, TNX-102 SL treatment resulted in significant improvements in the primary pain endpoint (RELIEF, p=0.010 and RESILIENT, p=0.00005). A responder analysis was performed to evaluate clinically meaningful reduction in pain, defined as a ≥30% reduction in the primary endpoint. A ≥50% responder analysis was also conducted. Safety assessments included reporting of adverse events (AEs).

Results:

In RESILIENT, compared to the placebo group, the TNX-102 SL group had a higher proportion of ≥30% responders (45.9% vs 27.1%; p< 0.001, uncorrected) and ≥50% responders (22.5% vs 13.3%; p=0.011, uncorrected). In RELIEF, the uncorrected p-value was 0.006 for ≥30% responder analysis and 0.141 for ≥50%. TNX-102 SL was generally well tolerated, with an AE profile that was similar to prior studies and was without new safety signals. The most common AE was transient tongue or mouth numbness at the administration site, which was mild and self-limited and rarely caused study discontinuation. Excluding COVID-19, all systemic AE rates were below 4.0%.

Conclusions/Implications for future research and/or clinical care:

In conclusion, TNX-102 SL significantly reduced pain and improved clinical outcomes in FM patients. Its favorable tolerability profile and novel mechanism targeting the sleep disturbance in FM make it a promising potential treatment.