Randomized, open-label, tolterodine-controlled, comparative study of the novel antimuscarinic agent imidafenacin in patients with overactive bladder

Mixed urinary incontinence: Are there effective treatments?

The aim of this debate article is to discuss whether effective treatments are available for mixed urinary incontinence (MUI). Because patients with MUI have both stress and urgency urinary incontinence (SUI and UUI) episodes and current treatment guidelines currently recommend treating the predominant symptom first, this article presents standard and emerging treatments for both SUI and UUI before discussing how well these treatments meet the medical needs of patients with MUI. Standard treatments presented include noninvasive options such as lifestyle changes and pelvic floor exercises, pharmacological agents, and surgery. Treatment of all three types of urinary incontinence (UI) is usually initiated with noninvasive options, after which treatment options diverge based on UI subtype. Multiple pharmacological agents have been developed for the treatment of UUI and overactive bladder, whereas surgery remains the standard option for SUI and stress-predominant MUI. The divide between UUI and SUI options seems to be propagated in emerging treatments, with most novel pharmacological agents still targeting UUI and even having SUI and stress-predominant MUI as exclusion criteria for participation in clinical trials. Considering that current treatment options focus almost exclusively on treating the predominant symptom of MUI and that emerging pharmacological treatments exclude patients with stress-predominant MUI during the development phase, effective treatments for MUI are lacking both in standard and emerging practice. Ideally, agents with dual mechanisms of action could provide symptom benefit for both the stress and urgency components of MUI.

Pharmacological Management of Urinary Incontinence: Current and Emerging Treatment

Pharmacological management of urinary incontinence (UI) is currently based on antimuscarinic and beta-3-agonist drugs. Botulinum toxin A detrusor injections represent an effective but more invasive alternative. This review covers the latest developments of the currently available drugs and the emerging compounds for the treatment of UI. Evidence shows that new antimuscarinics and beta-3-agonists with improved safety profiles may offer unique options to patients intolerant to currently available drugs. Combination therapy proved to be a non-invasive alternative for patients refractory to first-line monotherapy. Exciting advances are ongoing in the research to improve the efficacy/tolerability profile of botulinum toxin, through innovative routes of administration. Several new agents emerged from preclinical studies, some of which have now entered the clinical phase of development and could represent, in the coming years, a new way for the treatment of UI. Recent evidence on the existence of different overactive bladder phenotypes could be the key to tailored treatment. Rather than discovering new molecules, reaching the ability to identify the right drug for the right patient could be the real gamechanger of the future.

A double-blind, randomized, placebo-controlled, parallel study to evaluate the efficacy and safety of imidafenacin in patients with overactive bladder in Taiwan

OBJECTIVE

This study evaluated the efficacy and safety of imidafenacin 0.1 mg twice daily vs placebo for Taiwanese patients with overactive bladder (OAB) after a 12-week oral administration.

METHODS

This randomized, double-blind, placebo-controlled, two-arm, parallel-group, prospective study enrolled 118 patients across 11 study sites in Taiwan. Subjects were randomized to imidafenacin or placebo in a 2:1 ratio and entered the 12-week treatment period. At the subsequent visits, efficacy outcome measures and safety assessments were collected for analysis. The primary efficacy outcome was the change in the mean number of micturitions per day. Secondary endpoints included mean changes from baseline in urgency episodes and urge incontinence episodes per day and mean volume voided per micturition. Safety outcomes were also collected and compared between groups.

RESULTS

A total of 78 and 40 patients were allocated to the imidafenacin and placebo groups, respectively. Among them, 100 patients (imidafenacin, 65 and placebo, 35) completed the trial. Compared with placebo, imidafenacin was significantly better at reducing the number of micturitions per day (-1.29 ± 2.23 vs -0.46 ± 3.49, P = .0171) and reducing the mean number of urge incontinence episodes (-0.15 ± 0.52 vs 0.04 ± 0.50, P = .0386) at week 12. Adverse events were reported in 35 subjects (44.9%) and 16 (40%) in the imidafenacin and placebo groups, including constipation (n = 3, 4), dry mouth (n = 11, 2), and urinary tract infection (n = 7, 4), respectively. One patient in the imidafenacin group had mild dysuria.

CONCLUSION

Imidafenacin demonstrated efficacy and safety in the treatment of OAB in Taiwanese patients.

Is imidafenacin an alternative to current antimuscarinic drugs for patients with overactive bladder syndrome?

PURPOSE

Previous studies have included a limited number of randomized controlled trials (RCTs) and compared limited parameters after treatment with imidafenacin and other anticholinergic drugs (ADs) for overactive bladder syndrome (OAB), and controversy about the superiority of these ADs still remains. We aim to update the evidence and provide better clinical guidance.

METHODS

A systematic search of PubMed, Embase, ClinicalTrial.gov and Cochrane Library Central Register of Controlled Trials was conducted from January 2007 to April 2019. Meta-analysis of all published RCTs comparing imidafenacin with other ADs in patients with OAB was performed. The primary outcomes were the changes in OAB symptoms and OAB symptom score (OABSS). Secondary outcomes included adverse events (AEs) and the dropout rate related to AEs.

RESULTS

A total of 6 studies including 7 RCTs involving 1430 patients with mean follow-up of 23.43 weeks were included. All ADs improved OAB symptoms. Regarding efficacy, these drugs had similar efficacy in voids, urgency episodes, urgency incontinence episodes, incontinence episodes and OABSS. However, imidafenacin performed better in the reduction of nocturia episodes (MD = -0.24, 95% CI -0.44 to -0.04, P = 0.02). Moreover, imidafenacin was associated with a statistically lower dry mouth rate (RR = 0.87, 95% CI 0.75-1.00, P = 0.04), lower constipation rate (RR = 0.68, 95% CI 0.50-0.93, P = 0.01) and lower AE-related withdrawal rate (RR = 0.51, 95% CI 0.29-0.89, P = 0.02). There was no significant difference in terms of other complications.

CONCLUSIONS

In conclusion, imidafenacin was comparable to other ADs in the treatment of OAB. Moreover, imidafenacin presented a lower dry mouth rate, lower constipation rate and higher adherence and persistence.