Apnimed sees Phase 2 positive results for sulthiame to treat OSA 

CAMBRIDGE, Mass. - Apnimed has announced The Lancet has published positive results from the Phase 2 FLOW study evaluating sulthiame, a differentiated, once-daily oral carbonic anhydrase inhibitor, in the treatment of obstructive sleep apnea (OSA).

The study demonstrated that sulthiame significantly improved important OSA metrics in adults with moderate to severe OSA, the company says. 

"The positive data from the FLOW trial confirm previous proof-of-concept study results and suggest that sulthiame offers the potential to treat obstructive sleep apnea with a mechanism of action that is distinct from other investigational drugs, including that of our lead asset AD109," said Larry Miller, M.D., CEO of Apnimed. "Multiple mechanisms and approaches are needed if we are to effectively tackle the large prevalence, complexity and heterogeneity of OSA. We are thrilled to have these compelling data published in a peer reviewed scientific journal as prestigious as The Lancet, and are particularly encouraged by the consistent improvements seen across multiple efficacy measures. We look forward to working with our colleagues at Shionogi to advance sulthiame into further clinical development." 

Study design 

The FLOW study, a multicenter, randomized, double-blind, placebo-controlled, dose-finding trial, evaluated three dosages of sulthiame (100 mg, 200 mg, and 300 mg) administered once daily at bedtime for 15 weeks. The study enrolled 298 adult patients with untreated, moderate to severe OSA across 28 sites in five European countries. The primary endpoint, relative change in the apnea-hypopnea index (AHI3a) from baseline to Week 15, was met for all sulthiame doses. A dose-response effect was identified and well-characterized. 

Key findings 

• Significant reduction in OSA severity: All sulthiame doses demonstrated a consistent and dose-dependent reduction in breathing disturbances, as measured by AHI3a. 

• Improved nocturnal oxygenation: Sulthiame led to significant improvements in oxygen desaturation index (ODI) and mean overnight oxygen saturation, indicating improved nocturnal oxygenation. 

• Favorable safety profile: Sulthiame was generally well-tolerated, with adverse events consistent with prior experience and the known pharmacology of carbonic anhydrase inhibitors. Most adverse events were mild or moderate and dose-dependent. 

Related reading 

• Apnimed enters joint venture with Shionogi. 

• Apnimed announces positive results for sleep apnea pill, plans FDA filing.