PERSISTENCE IN THE TREATMENT OF OABWITH MIRABEGRON IN A MULTICENTRE CLINICAL STUDY
A. MARTAN1, K. SVABIK1, J. MASATA 1, J. KRHUT 2, R.ZACHOVAL 3, T. HANUS 4;
1Dpt. ofObstet. and Gynecol., 1st Faculty of Med., Charles Univ. and Gen.Univ. Hosp., Prague, Czech Republic, 2Dpt. of Urology,Univ. Hosp., Ostrava, Czech Republic, 3Dept. of Urology,Thomayer Hosp., Prague, Czech Republic, 4Dpt. of Urology,1st Faculty of Med., Charles Univ. and Gen. Univ. Hosp., Prague,Czech Republic.
Introduction: The first-linetreatment of overactive bladder symptoms (OAB) is the use ofpharmacologic therapy with antimuscarinic drugs, which are oftenassociated with poor levels of treatment persistence in patientssuffering from OAB. Recently mirabegron, a β3-adrenoreceptoragonist, has been included in the treatment of OAB.
Objective:The objective of this project was to evaluate treatment persistencein patients being treated for overactive bladder symptoms withmirabegron, employing clinical follow-up in a prospective,multicentre study.
Methods: This is an analysis ofmulticenter (6 gynecological and 4 urological centers) monitoring ofpatients who began treatment in May 2014 and were evaluated 18 monthsafter the first visit. The patients were all over 18 years of age andhad had symptoms of OAB for a minimum of 3 months. The dosage ofmirabegron was 50 mg per day for 162 patients, while for another 44patients at some point between the beginning of treatment and the18-month follow-up either the dosage of mirabegron was increased to100 mg per day (13 patients) or antimuscarinics (trospium orsolifenacin) were added (30 patients). One patient ended the18 months of treatment within the study on a dosage of mirabegron 100mg per day combined with antimuscarinics. During the check-up it wasascertained how many patients discontinued the treatment, and theirreasons were established. Discontinuation of the treatment was firstevaluated in the whole group. Then the patients involved in themonitoring were split into two groups: the first group comprised 75patients ≤ 60 years of age (36%), and the second group was of 131patients over 60 (64%). Discontinuation of therapy was evaluated inrelation to gender, treatment type (dosage of mirabegron) andprevious anticholinergic medication. For efficacy assessment we usedpatient perception of bladder condition scale (PPBC) and treatmentsatisfaction visual analogue scale TS-VAS. The statistics werecalculated using the software STATISTICA 12 (Statsoft, USA) and SPSS(IBM, v.20.0).
Results: Monitoring was performed on 206patients with OAB. 178 (86%) of patients had been givenanticholinergic treatment previously, for an average of 714 days (~ 2years). Their mean age when we started our study was 62.8 years(range 23-89), 62.7 years for females (range 23-89) years and 63.4years in the group of males (range 30-78). Mean body mass index (BMI)for the whole group of patients was 27.3 (SD 4.96): the male groupwas 27.6 (SD 3.85) and the females 27.3 (SD 5.14). We did not findany statistical significant differences between these groups. At thecheck-up 18 months (±2 weeks) post-initiation of treatment itemerged that 79 (38.3%) patients had discontinued the treatment. Thereasons for discontinuation in the whole group were: 28 (35.4%)insufficient treatment efficacy, 39(49.4%) other reasons (the mainreasons here were hospitalisation, surgery, gravidity, indispositionfor collaboration) and 12 (15.2%) discontinued therapy because ofside effects. The side effects were tachycardia, headache, vertigo,nausea, eye irritation, lower abdominal pain. In the group ofpatients ≤ 60, 75/206 patients (36.4%), there were 27/75 (36%)patients who terminated the study prematurely, 6/27 (22 %) of themfor insufficient efficacy, and 5/27 (19%) for reported side effects;in the group over 60, 131/206 (63.6%), there were 52/131 (40%)patients who discontinued the study, 22/52 (42%) due to insufficientefficacy, and 7/52 (13%) of them for reported side effects.Discontinuation of the treatment was 11/28 (39%) in the group ofpatients without previous treatment before mirabegron and 68/178(38%) in patients with previous anticholinergic treatment, mostfrequently involving solifenacin. When divided by gender the patientswho discontinued the study prematurely were 16/30 (53%) male /63/176(36%) female. The difference was not statistically significant(p=0.078). We found statistical significant differences in thediscontinuation rate between the group of patients who remained onthe initial 50mg dosage of mirabegron (76/162:47%) and the group ofpatients with increased dosage of 100 mg mirabegron or with acombination of mirabegron and antimuscarinics (3/44:7%). The meanPPBC score at baseline was 4.6 (SD 0.92) vs 2.7 (SD 1.26 ) at thelast follow-up, with score difference - 1.9 ( p<0.001), TS-VAS was73.4 (SD 21.93) at the last follow -up.
Conclusions: In ourclinical prospective multicenter study, persistence in treatment withmirabegron reached a figure of 61.7%. The reasons were good efficacyand reduced side effects of mirabegron.