ObjectiveTo investigate the safety and feasibility of precise delivery of a long-acting gel formulation containing 6% dexamethasone (SPT-2101) to the round window membrane for the treatment of Menière's diseaseStudy DesignProspective, unblinded, cohort studySettingTertiary care neurotology clinicPatientsAdults 18 to 85 years with a diagnosis of unilateral definite Menière’s disease per Barany society criteriaIntervention(s)A single injection of a long-acting gel formulation under direct visualization into the round window nicheMain Outcome Measure(s)Procedure success rate, adverse events, and vertigo control. Vertigo control was measured with definitive vertigo days (DVDs), defined as any day with a vertigo attack lasting 20 minutes or longer.ResultsTen subjects with unilateral Menière’s disease were enrolled. Precise placement of SPT-2101 at the round window was achieved in all subjects with in-office microendoscopy. Adverse events included one tympanic membrane perforation, which healed spontaneously after the study, and two instances of otitis media, which resolved with antibiotics. The average number of DVDs was 7.6 during the baseline month, decreasing to 3.3 by month 1, 3.7 by month 2, and 1.9 by month 3. Seventy percent of subjects had zero DVDs during the third month after treatment.ConclusionsSPT-2101 delivery to the round window is safe and feasible, and controlled trials are warranted to formally assess efficacy