Clinical Pharmacology for Myrbetriq
Mechanism Of Action
Mirabegron is an agonist of the human beta-3 adrenergic receptor (AR) as demonstrated by in vitro laboratory experiments using the cloned human beta-3 AR. Mirabegron relaxes the detrusor smooth muscle during the storage phase of the urinary bladder fill-void cycle by activation of beta-3 AR which increases bladder capacity. Although mirabegron showed very low intrinsic activity for cloned human beta-1 AR and beta-2 AR, results in humans indicate that beta-1 AR stimulation occurred at a mirabegron dose of 200 mg.
Pharmacodynamics
Urodynamics
The effects of mirabegron on maximum urinary flow rate and detrusor pressure at maximum flow rate were assessed in a urodynamic study consisting of 200 male patients with lower urinary tract symptoms (LUTS) and BOO. Administration of mirabegron once daily for 12 weeks did not adversely affect the mean maximum flow rate or mean detrusor pressure at maximum flow rate in this study. Nonetheless, mirabegron should be administered with caution to patients with clinically significant BOO [see WARNINGS AND PRECAUTIONS].
Cardiac Electrophysiology
The effect of multiple doses of mirabegron 50 mg, 100 mg, and 200 mg (four times the maximum recommended dose) once daily on QTc interval was evaluated in a randomized, placebo- and active-controlled (moxifloxacin 400 mg), four-treatment arm, parallel crossover study in 352 healthy subjects. In a study with demonstrated ability to detect small effects, the upper bound of the one-sided 95% confidence interval for the largest placebo-adjusted, baseline-corrected QTc based on individual correction method (QTcI) was below 10 msec. For the 50 mg mirabegron dose group (the maximum approved dosage), the mean difference from placebo on QTcI interval at 4 to 5 hours post-dose was 3.7 msec (upper bound of the 95% CI 5.1 msec).
For the mirabegron 100 mg and 200 mg dose groups (dosages greater than the maximum approved dose and resulting in substantial multiples of the anticipated maximum blood levels at 50 mg), the mean differences from placebo in QTcI interval at 4 to 5 hours post dose were 6.1 msec (upper bound of the 95% CI 7.6 msec) and 8.1 msec (upper bound of the 95% CI 9.8 msec), respectively. At the mirabegron 200 mg dose, in females, the mean effect was 10.4 msec (upper bound of the 95% CI 13.4 msec).
In this thorough QT study, mirabegron increased heart rate on ECG in a dose-dependent manner. Maximum mean increases from baseline in heart rate for the 50 mg, 100 mg, and 200 mg dose groups compared to placebo were 6.7 bpm, 11 bpm, and 17 bpm, respectively. In the clinical efficacy and safety studies, the change from baseline in mean pulse rate for mirabegron 50 mg was approximately 1 bpm. In this thorough QT study, mirabegron also increased blood pressure in a dose-dependent manner (see Effects On Blood Pressure).
Effects On Blood Pressure
In a study of 352 healthy subjects assessing the effect of multiple daily doses of 50 mg, 100 mg, and 200 mg (four times the maximum recommended dose) of mirabegron for 10 days on the QTc interval, the maximum mean increase in supine systolic blood pressure (SBP)/diastolic blood pressure (DBP) at the maximum recommended dose of 50 mg was approximately 4.0/1.6 mm Hg greater than placebo [see WARNINGS AND PRECAUTIONS]. The 24-hour average increases in SBP compared to placebo were 3.0, 5.5, and 9.7 mm Hg at mirabegron doses of 50 mg, 100 mg, and 200 mg, respectively. Increases in DBP were also dose-dependent, but were smaller than SBP.
In another study in 96 healthy subjects to assess the impact of age on pharmacokinetics of multiple daily doses of 50 mg, 100 mg, 200 mg, and 300 mg (six times the maximum recommended dose) of mirabegron for 10 days, SBP also increased in a dose-dependent manner. The mean maximum increases in SBP were approximately 2.5, 4.5, 5.5, and 6.5 mm Hg for mirabegron exposures associated with doses of 50 mg, 100 mg, 200 mg, and 300 mg, respectively.
In three, 12-week, double-blind, placebo-controlled, safety and efficacy studies (Studies 1, 2, and 3) in patients with OAB receiving mirabegron 25 mg, 50 mg, or 100 mg (two times the maximum recommended dose) once daily, mean increases in SBP/DBP compared to placebo of approximately 0.5 – 1 mm Hg were observed. Morning SBP increased by at least 15 mm Hg from baseline in 5.3%, 5.1%, and 6.7% of placebo, mirabegron 25 mg and mirabegron 50 mg patients, respectively. Morning DBP increased by at least 10 mm Hg in 4.6%, 4.1%, and 6.6% of placebo, mirabegron 25 mg, and mirabegron 50 mg patients, respectively. Both SBP and DBP increases were reversible upon discontinuation of treatment.
In a 12-week, double-blind, placebo-controlled, safety and efficacy study (Study 6) in patients with OAB receiving mirabegron 25 mg or 50 mg once daily coadministered with solifenacin succinate 5 mg, no consistent differences in 24-hour mean SBP/DBP were observed compared to placebo, mirabegron or solifenacin succinate monotherapy as assessed with 24-hour Ambulatory Blood Pressure Monitoring (ABPM). Similar frequencies of categorical changes were observed for combination treatment versus placebo in 24-hour mean SBP/DBP.
Effect On Intraocular Pressure (IOP)
Mirabegron 100 mg once daily did not increase IOP in healthy subjects after 56 days of treatment. In a phase 1 study assessing the effect of mirabegron on IOP using Goldmann applanation tonometry in 310 healthy subjects, a dose of mirabegron 100 mg was non-inferior to placebo for the primary endpoint of the treatment difference in mean change from baseline to day 56 in subject average IOP; the upper bound of the two-sided 95% CI of the treatment difference between mirabegron 100 mg and placebo was 0.3 mm Hg.
Pharmacokinetics
Absorption
MYRBETRIQ Monotherapy for Adult OAB
After oral administration of mirabegron in healthy volunteers, mirabegron was absorbed to reach maximum plasma concentrations (Cmax) at approximately 3.5 hours. The absolute bioavailability increased from 29% at a dose of 25 mg to 35% at a dose of 50 mg. Mean Cmax and AUC increased more than dose proportionally. This relationship was more apparent at doses above 50 mg. In the overall population of males and females, a 2-fold increase in dose from 50 mg to 100 mg mirabegron increased Cmax and AUCtau by approximately 2.9- and 2.6-fold, respectively, whereas a 4-fold increase in dose from 50 to 200 mg mirabegron increased Cmax and AUCtau by approximately 8.4- and 6.5-fold. Steady-state concentrations were achieved within 7 days of once daily dosing with mirabegron. After once daily administration, plasma exposure of mirabegron at steady-state was approximately double that seen after a single dose.
MYRBETRIQ/MYRBETRIQ Granules for Pediatric Neurogenic Detrusor Overactivity (NDO)
The median Tmax of mirabegron following oral administration of a single dose of MYRBETRIQ or mirabegron for extended-release oral suspension in pediatric patients under fed state was 4-5 hours. Population pharmacokinetic analysis predicted that the median Tmax of MYRBETRIQ or mirabegron for extended-release oral suspension at steady-state was 3-4 hours.
Effect Of Food
MYRBETRIQ Monotherapy for Adult OAB
There were no clinically significant differences in mirabegron pharmacokinetics when administered with or without food in adult patients.
MYRBETRIQ/MYRBETRIQ Granules for Pediatric Neurogenic Detrusor Overactivity (NDO)
In the fasted state, steady-state mirabegron AUC increased by 120% relative to the fed state in pediatric patients receiving MYRBETRIQ. Fasted Cmax and AUC increased by 170% and 80%, respectively, compared to the fed state following administration of MYRBETRIQ Granules in healthy volunteers.
Distribution
MYRBETRIQ Monotherapy for Adult OAB
Mirabegron is extensively distributed in the body. The volume of distribution at steady-state (Vss) is approximately 1670 L following intravenous administration. Mirabegron is bound (approximately 71%) to human plasma proteins, and shows moderate affinity for albumin and alpha-1 acid glycoprotein. Mirabegron distributes to erythrocytes. Based on an in vitro study, erythrocyte concentrations of 14C-mirabegron were about 2-fold higher than in plasma.
MYRBETRIQ/MYRBETRIQ Granules for Pediatric Neurogenic Detrusor Overactivity (NDO)
Mirabegron volume of distribution was relatively large in pediatric patients (the range of mean Vz/F under fed state in pediatric patients across studies: 4895-13726 L) and increased with increasing body weight.
Elimination
MYRBETRIQ Monotherapy for Adult OAB
The terminal elimination half-life (t1/2) of mirabegron is approximately 50 hours in patients.
MYRBETRIQ/MYRBETRIQ Granules for Pediatric Neurogenic Detrusor Overactivity (NDO)
The mean terminal elimination half-life (t1/2) of mirabegron is approximately 26 to 31 hours in pediatric patients.
Metabolism
Mirabegron is metabolized via multiple pathways involving dealkylation, oxidation, (direct) glucuronidation, and amide hydrolysis. Mirabegron is the major circulating component following a single dose of 14C-mirabegron. Two major metabolites were observed in human plasma and are phase 2 glucuronides representing 16% and 11% of total exposure, respectively. These metabolites are not pharmacologically active toward beta-3 adrenergic receptor. Although, in vitro studies suggest a role for CYP2D6 and CYP3A4 in the oxidative metabolism of mirabegron, in vivo results indicate that these isozymes play a limited role in the overall elimination. In healthy subjects who were genotypically poor metabolizers of CYP2D6, mean Cmax and AUCtau were approximately 16% and 17% higher than in extensive metabolizers of CYP2D6, respectively. In vitro and ex vivo studies have shown the involvement of butylcholinesterase, uridine diphospho-glucuronosyltransferases (UGT), and possibly alcohol dehydrogenase in the metabolism of mirabegron, in addition to CYP3A4 and CYP2D6.
Excretion
MYRBETRIQ Monotherapy for Adult OAB
Total body clearance (CLtot) from plasma is approximately 57 L/h following intravenous administration. Renal clearance (CLR) is approximately 13 L/h, which corresponds to nearly 25% of CLtot. Renal elimination of mirabegron is primarily through active tubular secretion along with glomerular filtration. The urinary elimination of unchanged mirabegron is dose-dependent and ranges from approximately 6.0% after a daily dose of 25 mg to 12.2% after a daily dose of 100 mg. Following the administration of 160 mg 14C-mirabegron solution to healthy volunteers, approximately 55% of the radioactivity dose was recovered in the urine and 34% in the feces. Approximately 25% of unchanged mirabegron was recovered in urine and 0% in feces.
MYRBETRIQ/MYRBETRIQ Granules for Pediatric Neurogenic Detrusor Overactivity (NDO)
Population pharmacokinetic model predicted that mirabegron clearance in pediatric patients increased with body weight.
Specific Populations
Geriatric Patients
The Cmax and AUC of mirabegron following multiple oral doses in elderly volunteers (≥ 65 years) were similar to those in younger volunteers (18 to 45 years) [see Use In Specific Populations].
Pediatric Patients
In patients 3 to less than 18 years of age, age was not predicted to affect mirabegron pharmacokinetic parameters after accounting for differences in body weight [see Use In Specific Populations].
Gender
MYRBETRIQ Monotherapy for Adult OAB
The Cmax and AUC of mirabegron were approximately 40% to 50% higher in females than in males. When corrected for differences in body weight, the mirabegron systemic exposure was 20%-30% higher in females compared to males.
MYRBETRIQ/MYRBETRIQ Granules for Pediatric Neurogenic Detrusor Overactivity (NDO)
Gender has no meaningful impact on mirabegron pharmacokinetics in the pediatric population from 3 to less than 18 years of age.
Race
The pharmacokinetics of mirabegron were comparable between Caucasians and African-American Blacks. Cross studies comparison showed that the exposure in Japanese subjects were higher than that in North American subjects. However, when the Cmax and AUC were normalized for dose and body weight, the difference was smaller.
Patients with Renal Impairment
Following single-dose administration of 100 mg mirabegron in adult volunteers with mild renal impairment (eGFR 60 to 89 mL/min/1.73 m2 as estimated by MDRD), mean mirabegron Cmax and AUC were increased by 6% and 31% relative to adult volunteers with normal renal function. In adult volunteers with moderate renal impairment (eGFR 30 to 59 mL/min/1.73 m2), Cmax and AUC were increased by 23% and 66%, respectively. In adult volunteers with severe renal impairment (eGFR 15 to 29 mL/min/1.73 m2), mean Cmax and AUC values were 92% and 118% higher compared to healthy subjects with normal renal function. Mirabegron has not been studied in adult patients with End-Stage Renal Disease (ESRD) (eGFR less than 15 mL/min/1.73 m2) or adult patients requiring dialysis.
Patients with Hepatic Impairment
Following single-dose administration of 100 mg mirabegron in adult volunteers with mild hepatic impairment (Child-Pugh Class A), mean mirabegron Cmax and AUC were increased by 9% and 19%, relative to adult volunteers with normal hepatic function. In adult volunteers with moderate hepatic impairment (Child-Pugh Class B), mean Cmax and AUC values were 175% and 65% higher. Mirabegron has not been studied in adult patients with severe hepatic impairment (Child-Pugh Class C).
Drug Interaction Studies
In Vitro Studies
Effect of Other Drugs on Mirabegron
Mirabegron is transported and metabolized through multiple pathways. Mirabegron is a substrate for CYP3A4, CYP2D6, butyrylcholinesterase, UGT, the efflux transporter P-glycoprotein (P-gp), and the influx organic cation transporters (OCT) OCT1, OCT2, and OCT3. Sulfonylurea hypoglycemic agents glibenclamide (a CYP3A4 substrate), gliclazide (a CYP2C9 and CYP3A4 substrate), and tolbutamide (a CYP2C9 substrate) did not affect the in vitro metabolism of mirabegron.
Effect of Mirabegron on Other Drugs
Studies of mirabegron using human liver microsomes and recombinant human CYP enzymes showed that mirabegron is a moderate and time-dependent inhibitor of CYP2D6 and a weak inhibitor of CYP3A. Mirabegron is unlikely to inhibit the metabolism of coadministered drugs metabolized by the following cytochrome P450 enzymes: CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and CYP2E1 because mirabegron did not inhibit the activity of these enzymes at clinically relevant concentrations. Mirabegron did not induce CYP1A2 or CYP3A. Mirabegron inhibited P-gp-mediated drug transport at high concentrations. Mirabegron is predicted not to cause clinically relevant inhibition of OCT-mediated drug transport. Mirabegron did not affect the metabolism of glibenclamide or tolbutamide.
Effect of Alcohol on Mirabegron
The addition of alcohol (5, 10, 20, and 40%) increases the dissolution rate of mirabegron from MYRBETRIQ Granules at pH 6.8. The clinical impact on the systemic exposure of mirabegron has not been evaluated. The addition of alcohol does not increase the dissolution rate of MYRBETRIQ Granules at pH 1.0 or MYRBETRIQ (extended-release tablets) regardless of pH.
In Vivo Studies
MYRBETRIQ Monotherapy for Adult OAB
The effect of coadministered drugs on the pharmacokinetics of mirabegron and the effect of mirabegron on the pharmacokinetics of coadministered drugs was studied after single and multiple doses of mirabegron. Most drug-drug interactions (DDI) were studied using mirabegron 100 mg extended-release tablets. However, interaction studies of mirabegron with metoprolol and with metformin were studied using mirabegron 160 mg immediate-release (IR) tablets.
The effect of ketoconazole, rifampicin, solifenacin succinate, tamsulosin, and metformin on systemic mirabegron exposure is shown in Figure 1.
The effect of mirabegron on metoprolol, desipramine, combined oral contraceptive-COC (ethinyl estradiol-EE, levonorgestrel-LNG), solifenacin succinate, digoxin, warfarin, tamsulosin, and metformin is shown in Figure 2.
In these studies, the largest increase in mirabegron systemic exposure was seen in the ketoconazole DDI study. As a potent CYP3A4 inhibitor, ketoconazole increased mirabegron Cmax by 45% and mirabegron AUC by 80% after multiple dose administration of 400 mg of ketoconazole for 9 days prior to the administration of a single dose of 100 mg mirabegron in 23 male and female healthy subjects.
As a moderate CYP2D6 inhibitor, mirabegron increased the systemic exposure to metoprolol and desipramine:
- Mirabegron increased the Cmax of metoprolol by 90% and metoprolol AUC by 229% after multiple doses of 160 mg mirabegron IR tablets once daily for 5 days and a single dose of 100 mg metoprolol tablet in 12 healthy male subjects administered before and concomitantly with mirabegron.
- Mirabegron increased the Cmax of desipramine by 79% and desipramine AUC by 241% after multiple dose administration of 100 mg mirabegron once daily for 18 days and a single dose of 50 mg desipramine before and concomitantly with mirabegron in 28 male and female healthy subjects.
The effect on the pharmacokinetics of coadministered digoxin and tamsulosin was studied after multiple doses of a combination of mirabegron and solifenacin succinate. Concomitant administration of 0.25 mg digoxin with a combination of 5 mg solifenacin succinate and 50 mg mirabegron increased digoxin AUCtau and Cmax by approximately 10% and 14%, respectively. Concomitant administration of 0.4 mg tamsulosin with a combination of 5 mg solifenacin succinate and 50 mg mirabegron increased tamsulosin AUCtau and Cmax by 47.5% and 54.3%, respectively. The observed changes in the pharmacokinetics of tamsulosin are in line with cytochrome P450 inhibition as shown by coadministration with mirabegron alone.
Figures 1 and 2 show the magnitude of these interactions on the pharmacokinetic parameters and the recommendations for dose adjustment, if any:
Figure 1: The Effect of Coadministered Drugs on Exposure of MYRBETRIQ and Dose Recommendation
 |
| (1) Although no dose adjustment is recommended with solifenacin succinate or tamsulosin based on the lack of pharmacokinetic interaction, MYRBETRIQ should be administered with caution to patients taking muscarinic antagonist medications for the treatment of OAB and in patients with clinically significant BOO because of the risk of urinary retention [see WARNINGS AND PRECAUTIONS]. |
Figure 2: The Effect of MYRBETRIQ on Exposure of Coadministered Medication
 |
(1) Since mirabegron is a moderate CYP2D6 inhibitor, the systemic exposure to CYP2D6 substrates such as metoprolol and desipramine is increased when coadministered with mirabegron. Therefore, appropriate monitoring and dose adjustment may be necessary, especially with narrow therapeutic index CYP2D6 substrates, such as thioridazine, flecainide, and propafenone [see WARNINGS AND PRECAUTIONS and DRUG INTERACTIONS].
(2) For patients who are initiating a combination of mirabegron and digoxin, the lowest dose for digoxin should initially be prescribed. Serum digoxin concentrations should be monitored and used for titration of the digoxin dose to obtain the desired clinical effect [see DRUG INTERACTIONS]. The same approach for the dose of digoxin should be followed when digoxin is coadministered with mirabegron and solifenacin succinate.
(3) Warfarin was administered as a single 25 mg dose of the racemate (a mixture of R-warfarin and S-warfarin). Based on this single-dose study, mirabegron had no effect on the warfarin pharmacodynamic endpoints such as INR and prothrombin time. However, the effect of mirabegron on multiple doses of warfarin and on warfarin pharmacodynamic end points such as INR and prothrombin time has not been fully investigated [see DRUG INTERACTIONS].
(4) Although no dose adjustment is recommended with solifenacin succinate or tamsulosin based on the lack of pharmacokinetic interaction, MYRBETRIQ should be administered with caution to patients taking muscarinic antagonist medications for the treatment of OAB and in BOO because of the risk of urinary retention [see WARNINGS AND PRECAUTIONS]. |
Clinical Studies
MYRBETRIQ Monotherapy For Adult OAB
MYRBETRIQ was evaluated in three, 12-week, double-blind, randomized, placebo-controlled, parallel group, multicenter clinical trials in patients with overactive bladder with symptoms of urge urinary incontinence, urgency, and urinary frequency (Studies 1, 2, and 3). Entry criteria required that patients had symptoms of overactive bladder for at least 3 months duration, at least 8 micturitions per day, and at least 3 episodes of urgency with or without incontinence over a 3-day period. The majority of patients were Caucasian (94%) and female (72%) with a mean age of 59 years (range 18 – 95 years). The population included both naïve patients who had not received prior muscarinic antagonist pharmacotherapy for overactive bladder (48%) and those who had received prior muscarinic antagonist pharmacotherapy for OAB (52%).
In Study 1 (NCT00689104), patients were randomized to placebo, MYRBETRIQ 50 mg, MYRBETRIQ 100 mg, or an active control once daily. In Study 2 (NCT00662909), patients were randomized to placebo, MYRBETRIQ 50 mg or MYRBETRIQ 100 mg once daily. In Study 3 (NCT00912964), patients were randomized to placebo, MYRBETRIQ 25 mg or MYRBETRIQ 50 mg once daily.
The co-primary efficacy endpoints in all 3 trials were (1) change from baseline to end of treatment (Week 12) in mean number of incontinence episodes per 24 hours and (2) change from baseline to end of treatment (Week 12) in mean number of micturitions per 24 hours, based on a 3-day micturition diary. An important secondary endpoint was the change from baseline to end of treatment (Week 12) in mean volume voided per micturition.
Results for the co-primary endpoints and mean volume voided per micturition from Studies 1, 2, and 3 are shown in Table 13.
Table 13: Mean Baseline and Change from Baseline at Week 121 for Incontinence Episodes, Micturition Frequency, and Volume Voided per Micturition in Patients with Overactive Bladder in Studies 1, 2, and 3
| Parameter |
Study 1 |
Study 2 |
Study 3 |
| Placebo |
MYRBETRIQ 50 mg |
Placebo |
MYRBETRIQ 50 mg |
Placebo |
MYRBETRIQ 25 mg |
MYRBETRIQ 50 mg |
| Number of Incontinence Episodes per 24 Hours2 |
| n |
291 |
293 |
325 |
312 |
262 |
254 |
257 |
| Baseline (mean) |
2.67 |
2.83 |
3.03 |
2.77 |
2.43 |
2.65 |
2.51 |
| Change from baseline (adjusted mean3) |
-1.17 |
-1.57 |
-1.13 |
-1.47 |
-0.96 |
-1.36 |
-1.38 |
| Difference from placebo (adjusted mean3) |
- |
-0.41 |
- |
-0.34 |
- |
-0.40 |
-0.42 |
| 95% Confidence Interval |
- |
(-0.72, -0.09) |
- |
(-0.66, -0.03) |
- |
(-0.74, -0.06) |
(-0.76, -0.08) |
| p-value |
- |
0.0034 |
- |
0.0264 |
- |
0.0054 |
0.0014 |
| Number of Micturitions per 24 Hours |
| n |
480 |
473 |
433 |
425 |
415 |
410 |
426 |
| Baseline (mean) |
11.71 |
11.65 |
11.51 |
11.80 |
11.48 |
11.68 |
11.66 |
| Change from baseline (adjusted mean3) |
-1.34 |
-1.93 |
-1.05 |
-1.66 |
-1.18 |
-1.65 |
-1.60 |
| Difference from placebo (adjusted mean3) |
- |
-0.60 |
- |
-0.61 |
- |
-0.47 |
-0.42 |
| 95% Confidence Interval |
- |
(-0.90, -0.29) |
- |
(-0.98, -0.24) |
- |
(-0.82, -0.13) |
(-0.76, -0.08) |
| p-value |
- |
< 0.0014 |
- |
0.0014 |
- |
0.0074 |
0.0154 |
| Volume Voided (mL) per Micturition |
| n |
480 |
472 |
433 |
424 |
415 |
410 |
426 |
| Baseline (mean) |
156.7 |
161.1 |
157.5 |
156.3 |
164.0 |
165.2 |
159.3 |
| Change from baseline (adjusted mean3) |
12.3 |
24.2 |
7.0 |
18.2 |
8.3 |
12.8 |
20.7 |
| Difference from placebo (adjusted mean3) |
- |
11.9 |
- |
11.1 |
- |
4.6 |
12.4 |
| 95% Confidence Interval |
- |
(6.3, 17.4) |
- |
(4.4, 17.9) |
- |
(-1.6, 10.8) |
(6.3, 18.6) |
| p-value |
- |
< 0.0014 |
- |
0.0014 |
- |
0.15 |
< 0.0014 |
1. Week 12 is the last observation on treatment.
2. For incontinence episodes per 24 hours, the analysis population is restricted to patients with at least 1 episode of incontinence at baseline.
3. Least squares mean adjusted for baseline, gender, and geographical region.
4. Statistically significantly superior compared to placebo at the 0.05 level with multiplicity adjustment. |
MYRBETRIQ 25 mg was effective in treating the symptoms of OAB within 8 weeks and MYRBETRIQ 50 mg was effective in treating the symptoms of OAB within 4 weeks. Efficacy of both 25 mg and 50 mg doses of MYRBETRIQ was maintained through the 12-week treatment period.
Figures 3 through 8 show the co-primary endpoints, mean change from baseline (BL) over time in number of incontinence episodes per 24 hours, and mean change from baseline over time in number of micturitions per 24 hours, in Studies 1, 2, and 3.
Figure 3: Mean (SE) Change from Baseline in Mean Number of Incontinence Episodes per 24 Hours – Study 1
Figure 4: Mean (SE) Change from Baseline in Mean Number of Micturitions per 24 Hours – Study 1
Figure 5: Mean (SE) Change from Baseline in Mean Number of Incontinence Episodes per 24 Hours – Study 2
Figure 6: Mean (SE) Change from Baseline in Mean Number of Micturitions per 24 Hours – Study 2
Figure 7: Mean (SE) Change from Baseline in Mean Number of Incontinence Episodes per 24 Hours – Study 3
Figure 8: Mean (SE) Change from Baseline in Mean Number of Micturitions per 24 Hours – Study 3
MYRBETRIQ Combination Therapy For Adult OAB
Coadministration Of MYRBETRIQ With Solifenacin Succinate
Coadministration of MYRBETRIQ with solifenacin succinate was evaluated in a 12-week, double-blind, randomized, placebo-controlled, parallel group, multicenter clinical trial in patients with OAB with symptoms of urge urinary incontinence, urgency, and urinary frequency (Study 6). Entry criteria required that patients had symptoms of OAB for at least 3 months duration, on average at least 8 micturitions and at least 1 urgency episode per day, and at least 3 episodes of incontinence, over a 7-day period. The majority of patients were Caucasian (80%) and female (77%) with a mean age of 57 years (range 18 to 86 years). The population included both naïve patients who had not received prior pharmacotherapy for OAB (54%) and those who had received prior pharmacotherapy for OAB (46%).
In Study 6 (NCT01972841), patients were randomized to placebo, solifenacin succinate 5 mg, MYRBETRIQ 25 mg, MYRBETRIQ 50 mg, solifenacin succinate 5 mg plus MYRBETRIQ 25 mg, or solifenacin succinate 5 mg plus MYRBETRIQ 50 mg once daily.
The co-primary efficacy endpoints in Study 6 were (1) change from baseline to end of treatment (week 12) in mean number of incontinence episodes per 24 hours and (2) change from baseline to end of treatment (week 12) in mean number of micturitions per 24 hours, based on a 7-day micturition diary. An important secondary endpoint was the change from baseline to end of treatment (week 12) in mean volume voided per micturition.
Results for the co-primary endpoints and mean volume voided per micturition for the overall patient population from Study 6 are shown in Table 14.
Table 14: Mean Baseline and Change from Baseline at Week 121 for Incontinence Episodes, Micturition Frequency, and Volume Voided per Micturition Overall Population with Overactive Bladder in Study 6
| Parameter |
Placebo |
MYRBETRIQ
25 mg |
MYRBETRIQ
50 mg |
Solifenacin Succinate
5 mg |
MYRBETRIQ 25 mg
+
Solifenacin Succinate 5 mg |
MYRBETRIQ 50 mg
+
Solifenacin Succinate 5 mg |
| Number of Incontinence Episodes per 24 Hours |
| n |
412 |
409 |
406 |
413 |
823 |
816 |
| Baseline (mean) |
3.40 |
3.42 |
3.16 |
3.59 |
3.21 |
3.15 |
| Change from baseline (adjusted mean2) |
-1.34 |
-1.70 |
-1.76 |
-1.79 |
-2.04 |
-1.98 |
| Difference from Solifenacin Succinate (adjusted mean2) |
- |
- |
- |
- |
-0.25 |
-0.20 |
| 95% Confidence Interval |
- |
- |
- |
- |
(-0.49, -0.01) |
(-0.44, 0.04) |
| Difference from MYRBETRIQ (at the same MYRBETRIQ dose, adjusted mean2) |
- |
- |
- |
- |
-0.34 |
-0.23 |
| 95% Confidence Interval |
- |
- |
- |
- |
(-0.58, -0.10) |
(-0.47, 0.01) |
| Number of Micturitions per 24 Hours |
| n |
412 |
409 |
406 |
413 |
823 |
816 |
| Baseline (mean) |
10.97 |
10.81 |
11.19 |
10.74 |
10.72 |
10.72 |
| Change from baseline (adjusted mean2) |
-1.64 |
-2.00 |
-2.03 |
-2.20 |
-2.49 |
-2.59 |
| Difference from Solifenacin Succinate (adjusted mean2) |
- |
- |
- |
- |
-0.29 |
-0.39 |
| 95% Confidence Interval |
- |
- |
- |
- |
(-0.57, -0.01) |
(-0.67, -0.11) |
| Difference from MYRBETRIQ (at the same MYRBETRIQ dose, adjusted mean2) |
- |
- |
- |
- |
-0.48 |
-0.56 |
| 95% Confidence Interval |
- |
- |
- |
- |
(-0.76, -0.21) |
(-0.84, -0.28) |
| Volume Voided (mL) per Micturition |
| n |
413 |
407 |
408 |
411 |
821 |
821 |
| Baseline (mean) |
157.82 |
152.46 |
155.35 |
151.86 |
159.19 |
153.83 |
| Change from baseline (adjusted mean2) |
8.44 |
13.32 |
21.99 |
30.99 |
34.84 |
39.73 |
| Difference from Solifenacin Succinate (adjusted mean2) |
- |
- |
- |
- |
3.85 |
8.75 |
| 95% Confidence Interval |
- |
- |
- |
- |
(-2.29, 10.00) |
(2.61, 14.89) |
| Difference from MYRBETRIQ (at the same MYRBETRIQ dose, adjusted mean2) |
- |
- |
- |
- |
21.52 |
17.74 |
| 95% Confidence Interval |
- |
- |
- |
- |
(15.35, 27.68) |
(11.58, 23.90) |
ANCOVA: Analysis of covariance
1. Week 12 is the last observation on treatment.
2. Least squares mean adjusted for baseline, gender, age group (< 65, ≥ 65 years), previous OAB medication (yes, no), and geographical region using an ANCOVA model. |
Figures 9 and 10 show the co-primary endpoints, mean change from baseline (BL) over time in number of incontinence episodes per 24 hours, and mean change from baseline over time in number of micturitions per 24 hours, in the overall patient population in Study 6.
Figure 9: Mean Change from Baseline in Mean (± SE) Number of Incontinence Episodes per 24 Hours at Each Visit (FAS) – Study 6
Figure 10: Mean Change from Baseline in Mean (± SE) Number of Micturitions per 24 Hours at Each Visit (FAS) – Study 6
MYRBETRIQ As Add-On Therapy To Solifenacin Succinate
MYRBETRIQ add-on therapy to solifenacin succinate was evaluated in one, 12-week, double-blind, randomized, active-controlled, multicenter clinical trial in incontinent OAB patients who received solifenacin succinate for 4 weeks and required additional relief for their OAB symptoms (Study 7). Entry criteria required that patients had symptoms of OAB for at least 3 months duration (urge urinary incontinence, urgency, and urinary frequency), and at least 1 incontinence episode during a 3-day period after being treated with solifenacin succinate 5 mg for 4 weeks. The majority of patients were Caucasian (94%) and female (83%) with a mean age of 57 years (range 18 to 89 years). Patients were randomized to solifenacin succinate 5 mg, solifenacin succinate 10 mg, or solifenacin succinate 5 mg plus MYRBETRIQ 25 mg once daily. After 4 weeks, all patients in the combination treatment arm had a dose increase from MYRBETRIQ 25 mg to MYRBETRIQ 50 mg.
The primary efficacy endpoint in Study 7 (NCT01908829) was change from baseline to end of treatment (week 12) in mean number of incontinence episodes per 24 hours. Two important secondary endpoints were change from baseline to end of treatment in mean number of micturitions per 24 hours and change from baseline to end of treatment in mean volume voided per micturition. Results for the primary and additional endpoints from Study 7 are shown in Table 15.
Table 15: Change from Baseline at Week 121 for Incontinence Episodes, Micturition Frequency, and Volume Voided per Micturition in Patients with Overactive Bladder in Study 7
| Parameter |
Solifenacin Succinate
5 mg |
MYRBETRIQ
25 mg/50 mg
+
Solifenacin
Succinate
5 mg |
| Number of Incontinence Episodes per 24 Hours |
| n |
704 |
706 |
| Baseline (mean) |
3.15 |
3.24 |
| Change from baseline (adjusted mean2) |
-1.53 |
-1.80 |
| Difference (MYRBETRIQ + Solifenacin Succinate) from Solifenacin Succinate (adjusted mean3) |
-0.26 |
- |
| 95% Confidence Interval |
(-0.47, -0.05) |
| Number of Micturitions per 24 Hours |
| n |
704 |
706 |
| Baseline (mean) |
8.90 |
9.13 |
| Change from baseline (adjusted mean2) |
-1.14 |
-1.59 |
| Difference (MYRBETRIQ + Solifenacin Succinate) from Solifenacin Succinate (adjusted mean3) |
-0.45 (0.12) |
- |
| 95% Confidence Interval |
(-0.67, -0.22) |
| Volume Voided (mL) per Micturition |
| n |
682 |
680 |
| Baseline (mean) |
170.92 |
172.93 |
| Change from baseline (adjusted mean2) |
16.52 |
28.05 |
| Difference (MYRBETRIQ + Solifenacin Succinate) from Solifenacin Succinate (adjusted mean3) |
11.52 |
- |
| 95% Confidence Interval |
(6.06, 16.99) |
ANCOVA: Analysis of covariance
1. Week 12 is the last observation on treatment.
2. Least squares mean adjusted for baseline, gender, age group (< 65, ≥ 65 years), geographical region, and 4-week incontinence reduction group using ANCOVA model.
3. Differences of adjusted means are calculated by subtracting the adjusted mean of solifenacin succinate monotherapy groups from adjusted mean of MYRBETRIQ + Solifenacin Succinate group based on ANCOVA model described above. |
Long-Term Coadministration Of MYRBETRIQ With Solifenacin Succinate
Long-term efficacy of coadministration of MYRBETRIQ 50 mg with solifenacin succinate 5 mg was evaluated in a 52-week, double-blind, randomized, active-controlled, parallel group, multicenter clinical trial in patients with OAB Study 8 (NCT02045862). The primary objective of this study was to evaluate the safety and tolerability of long-term combination treatment and the evaluation of efficacy was the secondary objective of the study. Entry criteria included patients who had completed Study 6 or Study 7 or new patients. All patients had symptoms of OAB for at least 3 months duration, on average at least 8 micturitions and at least 1 urgency episode per day, and at least 3 episodes of incontinence over a 7-day period. Patients were randomized to solifenacin succinate 5 mg, MYRBETRIQ 50 mg, or solifenacin succinate 5 mg plus MYRBETRIQ 50 mg once daily.
Primary efficacy variables were change from baseline to end of treatment in mean number of incontinence episodes per 24 hours and change from baseline to end of treatment in mean number of micturitions per 24 hours. Combination treatment with MYRBETRIQ and solifenacin succinate demonstrated statistically significant greater improvements from baseline compared to MYRBETRIQ 50 mg and solifenacin succinate 5 mg for both efficacy endpoints. The improvements from baseline observed with coadministration of MYRBETRIQ 50 mg and solifenacin succinate 5 mg compared to MYRBETRIQ 50 mg and solifenacin succinate 5 mg were demonstrated at 3 months and were maintained throughout the 1-year treatment period. Also, for the secondary efficacy variable of change from baseline to end of treatment in mean volume voided (MVV) per micturition, the increase in MVV was statistically significantly greater for combination treatment compared to the MYRBETRIQ 50 mg and solifenacin succinate 5 mg groups.
MYRBETRIQ/MYRBETRIQ Granules For Pediatric Neurogenic Detrusor Overactivity (NDO)
The efficacy of MYRBETRIQ/MYRBETRIQ Granules was evaluated in Study 9 (NCT02751931), a 52-week, open-label, baseline-controlled, multicenter, dose titration study in pediatric patients 3 years of age and older for the treatment of neurogenic detrusor overactivity (NDO). Study 9 included patients 3 to 17 years of age. Entry criteria required that patients had a diagnosis of neurogenic detrusor overactivity (NDO) with involuntary detrusor contractions with detrusor pressure increase greater than 15 cm H2O and that patients or their caregivers practiced clean intermittent catheterization (CIC). MYRBETRIQ/MYRBETRIQ Granules were administered orally once daily. All patients initially received a weight-based starting dose equivalent to 25 mg daily dose followed by dose titration to a dose equivalent of 50 mg daily dose. The duration of the dose titration period was up to 8 weeks and this period was followed by a dose maintenance period that continued for the duration of the 52-week study.
In Study 9, a total of 86 patients 3 to 17 years of age received MYRBETRIQ/MYRBETRIQ Granules. Of these, 71 patients completed treatment through week 24 and 70 completed 52 weeks of treatment. A total of 68 patients (43 patients 3 to less than 12 years of age and 25 patients 12 to 17 years of age) had valid urodynamic measurements for evaluation of efficacy. The study population included 39 males (45%) and 47 females (55%). The optimized maintenance dose within this study population included 94% of patients at the maximum dose, and 6% of patients at the starting dose.
The primary efficacy endpoint was change from baseline in the patients’ maximum cystometric (bladder) capacity (MCC) after 24 weeks of treatment with MYRBETRIQ/MYRBETRIQ Granules. As shown in Table 16, improvements in MCC were observed in patients 3 to less than 12 years of age and in patients 12 to 17 years of age. The magnitude of the observed changes from baseline in the primary and secondary efficacy endpoints were comparable between patients 3 to less than 12 years of age and patients 12 to 17 years of age.
Table 16: Change from Baseline in Maximum Cystometric Capacity (MCC) at 24Weeks in Pediatric Patients with Neurogenic Detrusor Overactivity (NDO) Treated with MYRBETRIQ/MYRBETRIQ Granules in Study 9
| Parameter |
Children
Aged 3 to Less than 12 Years
(N=43)1
Mean (SD) |
Adolescents
Aged 12 to 17 Years
(N=25)1
Mean (SD) |
| Maximum Cystometric Capacity (mL) |
| Baseline |
159 (95) |
239 (99) |
| Week 24 |
231 (129) |
352 (125) |
| Change from baseline |
72 (87) |
113 (83) |
| 95% CI |
(45, 99) |
(79, 147) |
| 1. N is the number of patients who took at least one dose and provided valid values for MCC at Baseline and Week 24. |
Secondary efficacy endpoints from Study 9 for MYRBETRIQ/MYRBETRIQ Granules in pediatric patients with neurogenic detrusor overactivity (NDO) are shown below in Table 17 and Table 18.
Table 17: Changes from Baseline in Other Urodynamic Parameters at Week 24 in Pediatric Patients with Neurogenic Detrusor Overactivity (NDO) Treated with MYRBETRIQ/MYRBETRIQ Granules in Study 9
| Parameter |
Children
Aged 3 to Less than 12 Years
(N=43)1
Mean (SD) |
Adolescents
Aged 12 to 17 Years
(N=25)1
Mean (SD) |
| BladderCompliance (mL/cmH2O)2 |
| Baseline |
16.0 (55.8) |
11.1 (10.7) |
| Change from baseline |
14.6 (42.1) |
13.6 (15.0) |
|
95% CI: -0.3, 29.5 |
95% CI: 6.7, 20.4 |
| Number of OveractiveDetrusor Contractions (> 15 cm H2O)2 |
| Baseline |
3.0 (4.0) |
2.1 (3.1) |
| Change from baseline |
-1.9 (4.2) |
-0.8 (3.9) |
|
95% CI: -3.3, -0.4 |
95% CI: -2.5, 0.9 |
| Bladder Volume Prior To First Detrusor Contraction (> 15 cm H2O)2 |
| Baseline |
115 (83) |
177 (117) |
| Change from baseline |
93 (88) |
121 (160) |
|
95% CI: 64, 122 |
95% CI: 54, 189 |
1. N is the number of patients who took at least one dose and provided valid values for MCC at Baseline and Week 24.
2. Number of patients (Children/Adolescents) with data available for both Baseline and Week 24; Bladder Compliance: n=33/21; Number of Overactive Detrusor Contractions: n=36/22; Bladder Volume Prior To First Detrusor Contraction: n=38/24. |
Table 18: Changes from Baseline in Maximum Catheterized Urine Volume and Number of Leakage Episodes at Week 24 in Pediatric Patients with Neurogenic Detrusor Overactivity (NDO) Treated with MYRBETRIQ/MYRBETRIQ Granules in Study 9
| Parameter |
Children
Aged 3 to Less than 12 Years
(N=43)1
Mean (SD) |
Adolescents
Aged 12 to 17 Years
(N=25)1
Mean (SD) |
| Maximum Catheterized Urine Volume per Day (mL)2 |
| Baseline |
304 (109) |
360 (111) |
| Change from baseline |
50 (104) |
84 (122) |
|
95% CI: 17, 83 |
95% CI: 32, 137 |
| Number of Leakage Episodes per Day2 |
| Baseline |
2.8 (3.7) |
1.8 (1.7) |
| Change from baseline |
-2.0 (3.2) |
-1.0 (1.1) |
|
95% CI: -3.2, -0.7 |
95% CI: -1.5, -0.5 |
1. N is the number of patients who took at least one dose and provided valid values for MCC at Baseline and Week 24.
2. Number of patients (Children/Adolescents) with data available for both Baseline and Week 24; Maximum Catheterized Urine Volume per Day: n=41/23; Number of Leakage Episodes per Day: n=26/21. |