Economic evaluation of pharmacological treatments for overactive bladder from the perspective of the UK National Health Service

Mirabegron in the Management of Overactive Bladder Syndrome

Overactive bladder (OAB) negatively affects work productivity and quality of life in sufferers. Its overall impact is likely to increase as a result of increasing prevalence in an ageing population. The pathophysiology of OAB is not completely understood but the β3-adrenoceptor, which is highly expressed in the urinary bladder, is thought to be important for mediating human detrusor relaxation during the storage phase. Clinical trial results have demonstrated that mirabegron, a selective β3-adrenoceptor agonist offers substantial clinical efficacy and good adherence rates over 12 months. Furthermore, due to its different mechanism of action, it is likely to offer a favourable tolerability profile when compared with antimuscarinic agents, resulting in improved persistence over long-term treatment. Finally, from a health economic perspective, despite its higher drug acquisition cost, mirabegron has been found to be cost-effective, owing to the greater increase in quality-adjusted-life-years gained, when compared to antimuscarinic medications. The PubMed database was searched for English language articles published between 1 January 2005 to 31 January 2022, on the subject of mirabegron. Search terms included "mirabegron", "overactive bladder", "β3-adrenoceptor agonist", "urinary incontinence". This review summarises the evidence for mirabegron as a treatment option for the management of OAB.

Review of Economic Value Drivers of the Treatment of Overactive Bladder

Overactive bladder (OAB) is a symptom-driven condition with economic burden estimated to be on the order of several hundred dollars or euros per patient in some North American and European countries. This work reviews recently published economic models to evaluate how health states are defined, what cost components are considered, and what utility values are used to estimate the cost effectiveness of OAB pharmacotherapies, botulinum toxin, or sacral neuromodulation. It was found that no clear standard exists for determining OAB health states, although most were defined by some measure of incontinence frequency. Costs of physician visits and incontinence pads were included in nearly all models; however, OAB-associated depression and nursing home costs were rarely included, despite being large cost drivers of global economic burden studies. Utility values used in the models ranged from 0.544 to 0.933, highlighting the uncertainty associated with how OAB patients value health-related quality of life. More research is warranted so that health states providing delineations among OAB symptom severity and quality of life are clinically and economically meaningful as well as meaningful to affected patients.

Mirabegron improves quality-of-life, treatment satisfaction, and persistence in patients with overactive bladder: a multi-center, non-interventional, real-world, 12-month study

OBJECTIVE

Observational studies can provide evidence about patient outcomes in routine clinical practice. This prospective, non-interventional study (BELIEVE) is the largest real-world European study to date to assess quality-of-life, treatment satisfaction, resource utilization, and persistence in patients with overactive bladder (OAB) who were prescribed mirabegron as part of routine clinical practice.

METHODS

The primary objective was to evaluate change from baseline in quality-of-life based on overactive bladder questionnaire (OAB-q) sub-scales. Secondary objectives included evaluation of treatment persistence, patient satisfaction, healthcare resource utilization and adverse events (AEs). Follow-up was for 12 months with visit windows at 2-4 and 10-12 months. Median change from baseline in total OAB-q and its sub-scales (Health-related quality-of-life [HRQoL] and symptom bother scale) were assessed.

RESULTS

Overall, 862 patients were enrolled from eight European countries. In the Full Analysis Set (FAS), 73.7% were female, mean age was 61.2 years; 47.7% ≥65 years. At baseline, 41.3% had switched from other OAB treatments, 42.2% were treatment naïve, 10.1% were lapsed, and 6.4% were on combination treatment. Symptom bother and HRQoL total scores improved from baseline to 2-4 and 10-12 months. There was a notable improvement in dry rate, increasing from 34.9% at baseline to 43.7% at 10-12 months in the FAS, and a reduction in pad use. Persistence was high, with 53.8% of FAS patients remaining on mirabegron at 10-12 months. Overall, no unexpected safety issues were observed and AEs were consistent with the known safety profile of mirabegron.

CONCLUSION

Patients receiving mirabegron in a real-world setting reported meaningful improvements in QoL and health status, with a persistence rate of 53.8% at 12 months for the FAS. No unexpected safety issues were observed, and AEs were consistent with the known safety profile of mirabegron.

Clinical and economic impact of mirabegron compared with antimuscarinics for the treatment of overactive bladder in Canada

BACKGROUND

The β₃-adrenoceptor agonist, mirabegron, and antimuscarinic agents provide similar efficacy for the treatment of overactive bladder (OAB), but mirabegron appears to be associated with better persistence, perhaps due to an absence of anticholinergic side-effects. This study estimated the expected costs associated with the management of OAB in Canada from a societal perspective by utilizing real-world evidence.

METHODS

An economic model with monthly cycles and a 1-year time horizon was developed to depict a treatment pathway for a hypothetical cohort of 100 patients with OAB. At model entry, patients receive mirabegron or an antimuscarinic. Patients who do not persist may switch treatment, undergo a minimally invasive procedure, or remain symptomatic (uncontrolled). The model includes direct costs (e.g. physician visits) and indirect costs (e.g. lost productivity). A one-way univariate sensitivity analysis assessed a ±20% variation in each of the key model inputs.

RESULTS

At 1 year, a greater proportion of patients persisted on treatment with mirabegron compared with antimuscarinics (33% vs 15-23%), and a smaller proportion switched treatment (17% vs 20-22%). The number of healthcare visits (292 vs 299-304), pads used (74,098 vs 77,878-81,669), and work hours lost (4,497 vs 5,372-6,249) were all lower for mirabegron vs antimuscarinics. The estimated total annual cost of treatment per patient with mirabegron was $2,127.46 Canadian dollars (CAD) ($5.82 CAD/day) compared with $2,150.20-$2,496.69 CAD ($5.89-$6.84 CAD/day) for antimuscarinics. The one-way sensitivity analysis indicated the results are robust.

CONCLUSIONS

Improved persistence observed in routine clinical practice with mirabegron appears to translate into benefits of reduced healthcare resource use, and lower direct and indirect costs of treatment compared with antimuscarinics. Overall, these data suggest that mirabegron may offer clinical and economic benefits for the management of patients with OAB in Canada.

Economic Impact of Mirabegron Versus Antimuscarinics for the Treatment of Overactive Bladder in the UK

PURPOSE

Our objective was to estimate the economic outcomes of using mirabegron versus antimuscarinics in the treatment of patients with overactive bladder (OAB) from a societal perspective in the UK.

MATERIALS AND METHODS

A Markov model was developed using Microsoft Excel^®. The time horizon and cycle length are 12 and 1 months, respectively; and the hypothetical cohort size 100 patients. Antimuscarinic comparators are fesoterodine, oxybutynin extended release (ER) and immediate release (IR), solifenacin, tolterodine ER/IR, trospium ER/IR, darifenacin and flavoxate. Model inputs included real-world treatment patterns data, healthcare resource use (e.g. clinic visits) and direct and indirect costs (e.g. drug acquisition and productivity loss). Model outputs included patient disposition, healthcare resource use, drug acquisition costs and other treatment-related costs over a 1-year time horizon. A one-way sensitivity analysis was performed to determine the key drivers of the model.

RESULTS

In a hypothetical cohort of 100 patients, total annual costs per patient were lower with mirabegron than with all antimuscarinics (£1270.84 vs. 1321.71-1607.48). Healthcare resource use was lower with mirabegron than with all antimuscarinics (115 vs. 119-123 general practitioner visits; 173 vs. 178-185 specialist visits and 0.0042 vs. 0.0050-0.0060 surgical operations) and fewer work hours were lost (4017 vs. 5114-6990 [all per 100 patients]). Sensitivity analysis showed the model was sensitive to persistence and switching rates, although the impact on the overall results was minimal.

CONCLUSIONS

In the UK, using mirabegron to treat OAB may improve persistence and lead to reductions in switching treatment, healthcare resource utilization, productivity costs, and overall treatment costs versus antimuscarinics.

Postmenopausal overactive bladder

Bladder storage symptoms have a severe impact on many areas as regards the quality of life including health-related, social, psychological and working functions. Pharmacotherapy of lower urinary tract stores (LUTS) has been developed to optimize neural control of the lower urinary tract in pathologic states. The bladder can be overactive or underactive. Overactive bladder (OAB) is highly prevalent and is associated with considerable morbidity, especially in aging population. Therefore, an effective treatment of OAB must result in a meaningful reduction in urinary symptoms. Pharmacotherapy for the OAB must be individualized based on the degree of bother, medication side-effect profile, concomitant comorbidities and current medication regimen. Antimuscarinic agents will continue to represent the current gold standard for the first-line pharmacological management of OAB. Alternatively to antimuscarinic therapy, β3-adrenergic receptor agonists, due to their efficacy and favorable adverse event profile, are a novel and attractive option of pharmacological treatment of overactive bladder symptoms. A combination of selective antimuscarinic and β3-adrenergic receptor agonists, agents with the different mechanism of action, gives a new treatment option for the patient with OAB according to its harms profile. A number of putative novel therapeutic agents is under clinical evaluations that may ultimately provide alternative or combination treatment options for OAB in the nearest future.