Mirabegron Can Improve Overactive Bladder Symptoms

MDLinx
07 Nov, 2019 ,

Mirabegron, a beta 3-adrenoreceptor agonist, was safe and effective in treating overactive bladder (OAB) across various patient groups, a pooled analysis shows. Dr. Chapple and colleagues pooled data from 10 Astellas Pharma-sponsored, phase 2-4 double-blind, 12-week mirabegron monotherapy studies in adults who had received one or more doses of the drug. Participants received 25 mg or 50 mg mirabegron; 2.5 mg, 5 mg or 10 mg solifenacin or 4 mg extended-release (ER) tolterodine. Solifenacin 2.5 mg and 10 mg were not included in the efficacy analyses because of small numbers.

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Mirabegron, a beta 3-adrenoreceptor agonist, was safe and effective in treating overactive bladder (OAB) across various patient groups, a pooled analysis shows.

Dr. Christopher Chapple of Royal Hallamshire Hospital in Sheffield, UK, told Reuters Health by email, "This detailed analysis confirms the findings of an earlier real-life clinical practice study, (which showed) that antimuscarinic agents are associated with significant, often intolerable, side effects, which leads to discontinuation of therapy...at a median of 56 days as compared to 169 days with mirabegron." (http://bit.ly/34LUt6b)

Dr. Chapple and colleagues pooled data from 10 Astellas Pharma-sponsored, phase 2-4 double-blind, 12-week mirabegron monotherapy studies in adults who had received one or more doses of the drug. Participants received 25 mg or 50 mg mirabegron; 2.5 mg, 5 mg or 10 mg solifenacin or 4 mg extended release (ER) tolterodine. Solifenacin 2.5 mg and 10 mg were not included in the efficacy analyses because of small numbers.

As reported online October 18 in European Urology, baseline hypertension and diabetes were more frequent across treatment groups in older (> 65) vs younger patients and in men vs women. Within sexes, frequencies were similar between groups.

Differences in baseline characteristics included type of incontinence and medical history between sexes.

Mirabegron 25 mg and 50 mg, solifenacin 5 mg, and tolterodine ER 4 mg were associated with greater improvement from baseline vs placebo in mean numbers/24 h of incontinence episodes, micturitions, urgency episodes, volume voided/micturition, and nocturia episodes.

The magnitude of the changes from baseline in the mean number of incontinence episodes/24 h was generally greater in older patients, women, and those who had received prior overactive OAB medication. Findings were similar in analyses of micturitions/24 h, urgency episodes/24 h, nocturia episodes, and mean volume voided/micturition.

"As with previous OAB studies, a high placebo response was observed," the authors noted. The use of bladder diaries likely contributed to this effect. Withdrawal from treatment was low across groups.

For the safety analyses, data were evaluated for aggregate treatment groups —i.e., placebo, total mirabegron (MIRA) and total antimuscarinics (AM)—rather than between individual treatment and dose groups. Generally, the frequency of treatment-emergent adverse events (TEAEs) was similar among the groups, although the incidence of dry mouth for the AM group was higher than that for the MIRA or placebo group, and more drug-related AEs were reported for the AM versus the MIRA group (21.4% vs 17.0%).

Further, overall, a higher frequency of TEAEs was reported for older vs younger patients and women vs men.

Dr. Chapple said, "Although it has not been studied in these trials, there is now mounting evidence of the potential negative impact of antimuscarinic therapy in producing cognitive dysfunction in the elderly." (http://bit.ly/36EzJ1D)

Dr. Peter Schlegel, urologist-in-chief at NewYork-Presbyterian and Weill Cornell Medicine in New York City, commented in an email to Reuters Health, "Many insurers do not reimburse for mirabegron, unless other similar medications have been used and failed. If this drug does not provide adequate benefit, other medications—i.e., anti-cholinergics—can still be tried, albeit with higher side effect profile."

The study was designed, analyzed and funded by Astellas Pharma Inc. Dr. Chapple and coauthors have received fees from the company.