CLINICAL PHARMACOLOGY
Mechanism Of Action
The antidiuretic effects of desmopressin are mediated by
stimulation of vasopressin 2 (V2) receptors, thereby increasing water
re-absorption in the kidneys, and reducing urine production.
Pharmacodynamics
In a pharmacodynamic study following sublingual
administration of 60 mcg desmopressin (1.2 and 2.4 times the maximum
recommended dose in men and women, respectively) with suppression of the
endogenous vasopressin release by continuous intake of water, the mean time to
onset of antidiuretic action was observed within 30 minutes and lasted 6 hours
after dosing.
In a study in patients with nocturia due to nocturnal
polyuria, the weight-corrected NOCDURNA dose that induced 50% maximum
achievable drug effect on nocturnal urine volume (ED50) differed significantly
between women and men. The ED50 value for men was 2.7-fold (95% CI 1.3-8.1)
higher than the value for women, corresponding to higher desmopressin
sensitivity among women [see DOSAGE AND ADMINISTRATION].
Dose, sex, age and renal impairment affect the risk of
developing hyponatremia [see WARNINGS AND PRECAUTIONS].
Pharmacokinetics
The pharmacokinetics of desmopressin following sublingual
administration of NOCDURNA has not been characterized. The pharmacokinetic
information provided below is from studies following sublingual administration
of higher doses or intravenous injection of desmopressin.
Absorption
The overall mean absolute bioavailability of desmopressin
administered sublingually (at doses of 200, 400 and 800 mcg, which represents
4, 8, and 16 times the maximum recommend dosage in men) was 0.25% (95% CI 0.21–0.31%).
Distribution
The volume of distribution of desmopressin after
intravenous administration of 2 mcg is 26.5 L.
Elimination
The geometric mean terminal half-life is 2.8 hours.
Metabolism
In vitro studies in human liver microsome preparations
have shown that desmopressin is not a substrate for the human CYP450 system.
Excretion
Desmopressin is mainly excreted in the urine. After
intravenous administration of 2 mcg, 52% of the dose was recovered in the urine
within 24 hours as unchanged desmopressin.
Drug Interaction Studies
In vitro studies in human liver microsome preparations
have shown that desmopressin does not inhibit the human CYP450 system. No in
vivo interaction studies have been performed with NOCDURNA.
Patients With Renal Impairment
A pharmacokinetic study was conducted in subjects with
normal renal function and patients with mild, moderate, and severe renal
impairment (n=24, 6 subjects in each group) who received a single 2 mcg dose of
desmopressin intravenous injection.
The geometric mean terminal half-life was 2.8 hours in
subjects with normal renal function, and 4, 6.6, and 8.7 hours in patients with
mild, moderate, and severe renal impairment, respectively. In patients with
mild, moderate and severe renal impairment, mean desmopressin area under the plasma
drug concentration time curve (AUC) was 1.5-fold, 2.4-fold and 3.7-fold higher,
respectively, compared to that of subjects with normal renal function [see CONTRAINDICATIONS,
Use In Specific Populations].
Clinical Studies
The efficacy of NOCDURNA in the treatment of adults with
nocturia due to nocturnal polyuria was established in two 3-month randomized,
double-blind, placebo-controlled, multicenter trials in adults over 18 years of
age. Study 1 enrolled only women and Study 2 enrolled only men. At baseline,
patients were required to document at least two nocturnal voids per night in a consecutive
3-day diary collected during screening. Randomization for studies 1 and 2 was stratified
by age group (<65 vs. ≥65 years). Subjects with severe daytime voiding
dysfunction and other possible causes of nocturia (e.g., uncontrolled diabetes
mellitus, obstructive sleep apnea) were excluded.
In Studies 1 and 2, the mean age was approximately 60
years and the ethnic/racial distribution was approximately 80% Caucasian, 20%
African American, and 1% Asian.
In Study 1, a total of 237 women with nocturia due to
nocturnal polyuria were randomized to receive either sublingual NOCDURNA 27.7
mcg (n=121) or placebo (n=116) every night approximately 1 hour prior to
bedtime for 3 months. In Study 2, a total of 230 men with nocturia due to
nocturnal polyuria were randomized to receive sublingual NOCDURNA 55.3 mcg
(n=102) or placebo (n=128) every night approximately 1 hour prior to bedtime
for 3 months. Nocturnal polyuria was defined as nighttime urine production
exceeding one-third of the 24-hour urine production confirmed with a 24-hour
urine frequency/volume chart.
The co-primary efficacy endpoints in each trial were 1) the
change in number of nocturia episodes per night from baseline during the
3-month treatment period, and 2) 33% responder status during three months of
treatment. A 33% responder was defined as a subject with a decrease of at least
33% in the mean number of nocturnal voids compared to baseline.
Many conditions can cause nocturia. The efficacy and
safety of NOCDURNA have not been established for the treatment of all causes of
nocturia. NOCDURNA is indicated only for patients who have nocturia due to
nocturnal polyuria.
The results for the co-primary efficacy endpoints among
patients with nocturia due to nocturnal polyuria are shown in Table 5.
Table 5: Primary Efficacy Results in Subjects with
Nocturia due to Nocturnal Polyuria in Studies 1 and 2 (mITT population)
|
Women (Study 1) |
Men (Study 2) |
Placebo
N=114 |
NOCDURNA 27.7 mcg once daily
N=118 |
Placebo
N=128 |
NOCDURNA 55.3 mcg once daily
N=102 |
Mean number of nocturnal voids |
Baseline (mean) |
2.9 |
2.9 |
3.0 |
3.0 |
Change from baseline1 |
-1.2 |
-1.5 |
-0.9 |
-1.3 |
Difference from placebo1 |
-0.3 |
-0.4 |
95% CI1 |
(-0.5, -0.1) |
(-0.6, -0.2) |
33% responder status |
Probability2 |
0.62 |
0.78 |
0.50 |
0.67 |
Odds Ratio2 |
2.15 |
2.02 |
95% CI2 |
(1.36, 3.41) |
(1.30, 3.14) |
mITT: modified Intent-to-Treat (including all randomized
patients who received at least one dose of study drug)
CI = confidence interval
1 Repeated measures ANCOVA of change from baseline at Week 1, Month
1, Month 2 and Month 3, adjusted for age stratification factor (<65, ≥65
years), visit, and baseline nocturnal voids
2 GEE Method for 33% responder status at Week 1, Month 1, Month 2
and Month 3, adjusted for age stratification factor (<65, ≥65 years),
visit, and baseline nocturnal voids |
To help interpret the clinical meaningfulness of the
efficacy findings, results of the additional analyses for the percentage of
nights during the 3-month treatment period with no nocturia and the percentage
of nights during the 3-month treatment period with at most one nocturia
episode, are displayed in Table 6.
Table 6 : Summary of Additional Analysis Results in
Subjects with Nocturia due to Nocturnal Polyuria in Studies 1 and 2 (mITT
population)
|
Women (Study 1) |
Men (Study 2) |
Placebo
N=114 |
NOCDURNA 27.7 mcg once daily
N=118 |
Placebo
N=128 |
NOCDURNA 55.3 mcg once daily
N=102 |
Percentage of nights with at most one nocturnal void |
Baseline (mean) |
0% |
1% |
1% |
0% |
Percentage1 |
45% |
58% |
32% |
44% |
Difference from placebo1 |
|
13% |
|
11% |
95% CI1 |
|
(4%, 21%) |
|
(3%, 20%) |
Percentage of nights with no nocturnal voids |
Baseline (mean) |
0% |
0% |
0% |
0% |
Percentage1 |
15% |
19% |
7% |
15% |
Difference from placebo1 |
|
4% |
|
9% |
95% CI1 |
|
(-3%, 11%) |
|
(4%, 14%) |
mITT: modified Intent-to-Treat (including all randomized
patients who received at least one dose of study drug)
CI: confidence interval
1 ANCOVA model adjusted for treatment, age stratification factor
(<65, ≥65 years), and baseline nocturnal voids |