Randomized Controlled Trial Evaluating Efficacy & Safety of a Novel Stress Incontinence Device

Objectives: To compare the safety and efficacy of a novel intravaginal insert (Yōni.Fit®) compared to sham, for stress urinary incontinence (SUI) in women.

Methods: This multicenter, randomized, sham-controlled, single-blind trial enrolled women with SUI for ≥3 months with a positive cough stress test. Participants were randomized to either the novel device (Yōni.Fit®, Figure 1) or sham device. After a brief training, participants self-fit from 6 sizes and wore the insert daily for 12 hours. Twelve-hour pad weights, voiding diaries and subjective outcome measures were collected after baseline (1 week), fitting (1 week), treatment (1 week) and open-label (4 weeks) phases, during which sham subjects could cross-over to the novel device. The primary outcome was responder rate, defined as ≥50% reduction in pad weights during treatment. Secondary endpoints included change in pad weight, change in frequency of SUI episodes, ≥50% reduction in SUI episodes, number of dry days, patient global impression of change (PGIC) score, Incontinence-Quality of Life (I-QOL) Assessment Questionnaire and the Usefulness, Satisfaction, and Ease of Use (USE) Questionnaire. A sample size of 70 subjects achieved 80% power at α-0.05 assuming a responder rate of 58% in the novel device, 25% in the sham, and 30% dropout. Data were analyzed as modified intention-to-treat and per protocol.

Results: From January 2020 to August 2022, 79 patients were screened for eligibility, 71 enrolled, 58 were randomized, 56 completed treatment phase and 54 continued to the open label phase. Demographic characteristics were similar between groups and all subjects were able to self-fit the devices. In the treatment phase, responder rate based on pad weights was higher for the novel device compared to sham (53.0% vs 23.3%, p=0.013, absolute difference 29.6%, 95% confidence interval 7.4% to 51.8%). The percent change in SUI episodes was higher in the novel device compared to sham (p< 0.001). Greater than 50% reduction in SUI episodes from baseline occurred in 96.3% of subjects using the novel device and 27.2% of the sham (p< 0.001). At the end of treatment phase, more subjects using the novel device felt their status was “much improved” or better compared to sham (p=0.001). Participants using the novel device scored higher on the USE Questionnaire subdomain of usefulness (Table 1). The adverse event (AE) rate during fitting and treatment phases was 54.8% in the novel device and 29.6% in the sham. The most common AE was vaginal discomfort in 9 novel versus 5 sham subjects. There were no device-related serious AEs.

Conclusions: More patients using the novel vaginal device (Yōni.Fit®) had a ≥50% reduction in pad weights, less SUI events and felt the novel device was more useful compared to sham. AEs were mild. Additional studies are warranted to assess safety in long-term use.