BACKGROUND OF THE INVENTION
[0001] This invention relates to an ophthalmic pharmaceutical composition for use in a method
of treatment of glaucoma or ocular hypertension, the composition comprising an effective
amount of brimonidine tartrate and an effective amount of timolol maleate in a pharmaceutically
acceptable carrier therefor. Such combinations or formulations are available for separate
use in the ophthalmic art and have been combined in serial application during the
course of treatment of glaucoma. However, there are concerns and expressed reservations
in the ophthalmic community about patient compliance when the patient is required
to administer separate medications to treat a single disease or condition such as
glaucoma. There is, moreover, a long felt need for an effective and safe topical ophthalmic
pharmaceutical composition including brimonidine tartrate and timolol maleate which
has increased stability and requires a lower effective concentration of preservative
as compared to the individual agents taken alone. Finally, there is a need to increase
the efficacy of many topical ophthalmic agents, without increasing the systemic concentration
of such topical agents, since it is well known that many of such topically-applied
ophthalmic agents cause systemic side effects, e.g. drowsiness, heart effects, etc.
Unexpectedly it has been discovered that brimonidine tartrate in combination with
timolol maleate meets these criteria.
DESCRIPTION OF THE INVENTION
[0004] Brimonidine tartrate is an alpha adrenergic agonist represented by the following
formula:

[0005] The chemical name for brimonidine tartrate is 5-Bromo-6-(2-imidazolidinylideneamino)quinoxaline
L-tartrate.
[0006] Timolol maleate is a beta adrenergic agent represented by the following formula:

[0007] Brimonidine tartrate is available from Allergan, Inc., Irvine, California as an ophthalmic
pharmaceutical product having the name Alphagan®.
[0008] Timolol maleate is available from various sources, including Merck Co., Rahway, New
Jersey.
[0009] The compositions of the present invention are administered topically. The dosage
is preferably 0.001 to 1.0, e.g. mg/per eye BID; wherein the cited mass figures represent
the sum of the two components, brimonidine tartrate and timolol maleate. The compositions
of the present invention can be administered as solutions in a suitable ophthalmic
vehicle.
[0010] In forming compositions for topical administration, the mixtures are preferably formulated
as 0.01 to 0.5 percent by weight brimonidine tartrate and 0.1 to 1.0 percent by weight
timolol maleate solution in water at a pH of 4.5 to 8.0, e.g. about 6.9. While the
precise regimen is left to the discretion of the clinician, it is recommended that
the solution be topically applied by placing one drop in each eye two times a day.
Other ingredients which may be desirable to use in the ophthalmic preparations of
the present invention include preservatives, co-solvents and viscosity building agents.
Antimicrobial Preservative:
[0011] Ophthalmic products are typically packaged in multidose form. Preservatives are thus
required to prevent microbial contamination during use. Suitable preservatives include:
benzalkonium chloride, thimerosal, chlorobutanol, methyl paraben, propyl paraben,
phenylethyl alcohol, edetate disodium, sorbic acid, Onamer M, or other agents known
to those skilled in the art. In the prior art ophthalmic products, typically such
preservatives are employed at a level of from 0.004% to 0.02%. In the compositions
of the present application the preservative, preferably benzalkonium chloride, may
be employed at a level of from 0.001% to less than 0.01%, e.g. from 0.001% to 0.008%,
preferably about 0.005% by weight. It has been found that a concentration of benzalkonium
chloride of 0.005% is sufficient to preserve the compositions of the present invention
from microbial attack. This concentration may be advantageously compared to the requirement
of 0.01 % benzalkonium chloride to preserve timolol in the individual, commercially-available
ophthalmic products. Moreover, it has been found that adequate lowering of intraocular
pressure has been obtained when administering the compositions of this invention twice
a day as compared to the FDA-approved regimen wherein brimonidine ophthalmic solution,
i.e. Alphagan® ophthalmic solution is administered three times a day and timolol ophthalmic
solution, i.e. Timoptic® ophthalmic solution is administered twice a day. This results
in the exposure of the patient to 67% and 50% of benzalkonium chloride, with the compositions
of this invention, as compared to the administration of Alphagan® and Timoptic®, respectively.
In FDA-approved adjunctive therapy, wherein Alphagan® and Timoptic® are serially administered,
the patient is exposed to almost three times the concentration of benzalkonium chloride
as compared to the administration of the compositions of this invention twice a day.
(It is noted that it is known that benzalkonium chloride at high concentrations is
cytotoxic. Therefore, minimizing the patient's exposure to benzalkonium chloride,
while providing the preservative effects afforded by benzalkonium chloride, is clearly
desirable.)
Co-Solvents:
[0012] The solubility of the components of the present compositions may be enhanced by a
surfactant or other appropriate co-solvent in the composition. Such cosolvents include
polysorbate 20, 60, and 80, Pluronic F68, F-84 and P-103, cyclodextrin, or other agents
known to those skilled in the art. Typically such co-solvents are employed at a level
of from 0.01% to 2% by weight.
Viscosity Agents:
[0013] Viscosity increased above that of simple aqueous solutions may be desirable to increase
ocular absorption of the active compound, to decrease variability in dispensing the
formulation, to decrease physical separation of components of a suspension or emulsion
of the formulation and/or to otherwise improve the ophthalmic formulation. Such viscosity
building agents include as examples polyvinyl alcohol, polyvinyl pyrrolidone, methyl
cellulose, hydroxy propyl methylcellulose, hydroxyethyl cellulose, carboxymethyl cellulose,
hydroxy propyl cellulose or other agents known to those skilled in the art. Such agents
are typically employed at a level of from 0.01% to 2% by weight.
[0014] The present invention further comprises an article of manufacture comprising packaging
material and a pharmaceutical agent contained within said packaging material, wherein
the pharmaceutical agent is therapeutically effective for lowering intraocular pressure
and wherein the packaging material comprises a label which indicates the pharmaceutical
agent can be used for lowering intraocular pressure and wherein said pharmaceutical
agent comprises an effective amount of brimonidine and an effective amount of timolol.
[0015] The following example is a representative pharmaceutical composition of the invention
for topical use when indicated for treating glaucoma.
EXAMPLE I
[0016] The combination of active pharmaceutical ingredients is as follows: Brimonidine Tartrate
0.20 %(w/v) and Timolol Maleate 0.68 %(w/v) (Equivalent to 0.50 %(w/v) timolol)
[0017] The Brimonidine-Timolol combination formulation presented in the Table, below, is
a sterile, preserved, aqueous solution. The formulation vehicle is based upon a timolol
ophthalmic solution which contains an isotonic phosphate buffer system at pH 6.9.
The formulation preservative is benzalalkonium chloride (BAK) at a concentration of
0.005 %(w/v) (50 ppm). The formulation passes regulatory required preservative efficacy
testing (PET) criteria for USP (United States Pharmacopoeia) and EP (European Pharmacopoeia-A
and -B over 24 months.
Table
| Ingredient |
Function |
Concentration, %(w/v) |
| Brimonidine Tartrate |
Active |
0.2 |
| Timolol Maleate, EP |
Active |
0.681 |
| Benzalkonium Chloride, NF, EP |
Preservative |
0.005 |
| Sodium Phosphate, monobasic monohydrate, USP |
Buffer |
0.43 |
| Sodium Phosphate, dibasic heptahydrate, USP |
Buffer |
2.15 |
| Sodium Hydroxide, NF |
pH adjust |
Adjust pH to 6.9 |
| Hydrochloric Acid, NF |
pH adjust |
Adjust pH to 6.9 |
| Purified Water, USP, EP |
Solvent |
q.s. ad |
| 1 Equivalent to 0.5%(w/v) Timolol, free base |
[0018] The pharmaceutical composition of Example I is used in the clinical study reported
below.
EXAMPLE II
Objectives:
[0019] To compare the safety and efficacy of twice-daily dosed brimonidine tartrate 0.2%/timolol
0.5% ophthalmic solution combination (henceforth referred to as Combination) with
that of twice-daily dosed timolol ophthalmic solution 0.5% (henceforth referred to
as Timolol) and three-times-daily dosed ALPHAGAN
® (brimonidine tartrate ophthalmic solution) 0.2% (henceforth referred to as Brimonidine)
administered for three months (plus 9-month masked extension) in patients with glaucoma
or ocular hypertension.
Methodology:
[0020]
Structure: multicenter, double-masked, randomized, parallel-group, active control
Randomization: patients were randomized to one of the 3 masked treatment groups (Combination, Brimonidine
or Timolol) based on an even allocation at each site
Visit Schedule: prestudy, baseline (day 0), week 2, week 6, month 3, month 6, month 9, and month
12
Number of Patients (Planned and Analyzed):
[0021] 560 planned to enroll; 586 enrolled (Combination = 193, Brimonidine = 196, Timolol
= 197); 502 completed. Mean (range) age: 62.4 (23 to 87) years; 46.1% (270/586) males,
53.9% (316/586) females.
Diagnosis and Main Criteria for Inclusion:
[0022]
Diagnosis: ocular hypertension, chronic open-angle glaucoma, chronic angle-closure glaucoma
with patent iridotomy, pseudoexfoliative glaucoma or pigmentary glaucoma and requiring
bilateral treatment.
Key Inclusion Criteria: ≥ 18 years, day 0 (post-washout) intraocular pressure (IOP) ≥ 22 mm Hg and ≤ 34
mm Hg in each eye and asymmetry of IOP ≤ 5 mm Hg, best-corrected Early Treatment of
Diabetic Retinopathy Study (ETDRS) visual acuity equivalent to a Snellen score of
20/100 or better in each eye.
Key Exclusion Criteria: uncontrolled systemic disease, abnormally low or high blood pressure or pulse rate
for age or contraindication to beta-adrenoceptor antagonist therapy, anticipated alteration
of existing chronic therapy with agents which could have a substantial effect on IOP,
contraindication to brimonidine therapy, allergy or sensitivity to any of the study
medication ingredients, anticipated wearing of contact lenses during the study, laser
surgery, intraocular filtering surgery or any other ocular surgery within the past
3 months, or required chronic use of other ocular medications during the study (intermittent
use of artificial tear product was allowed).
Test Product, Dose and Mode of Administration, Batch Number:
[0023] Brimonidine tartrate 0.2%/timolol 0.5% combination ophthalmic solution one drop (~35
µL) instilled in each eye BID in the morning and evening; and vehicle of the Combination
ophthalmic solution, one drop (~35 µL) instilled in each eye once daily (QD) in the
afternoon (for masking purposes).
Duration of Treatment: 3 months (with a 9-month masked extension)
Reference Therapy, Dose and Mode of Administration, Batch Number:
[0024] Active control ALPHAGAN
® (brimonidine tartrate ophthalmic solution) 0.2%, one drop (~35 µL) instilled in each
eye TID in the morning, afternoon, and evening. Active control timolol ophthalmic
solution 0.5%, one drop (~35 µL) instilled in each eye BID in the morning and evening;
and vehicle of the Combination ophthalmic solution, one drop (~35 µL) instilled in
each eye once daily (QD) in the afternoon (for masking purposes).
Criteria for Evaluation:
Efficacy:
[0025] IOP (hours 0, 2, 7, and 9), patient satisfaction questionnaire, patient comfort of
study medication questionnaire, pharmacoeconomic evaluation by investigator
Safety:
[0026] Adverse events (AE); biomicroscopy, visual acuity (VA), visual field, ophthalmoscopy,
cup/disc ratio, heart rate, blood pressure, hematology, serum chemistry, urinalysis
and pregnancy test.
Other:
[0027] Quantitation of plasma brimonidine and timolol concentrations (at selected sites),
resource utilization (to be reported upon completion of the 1 year study).
Statistical Methods:
[0028] All data were summarized with descriptive statistics, frequency tables, and/or data
listings. Safety analyses included all patients who received at least 1 dose of study
medication. Analyses were performed for the primary efficacy variable IOP using the
intent-to-treat (ITT) population with last observation carried forward (LOCF), and
the per protocol population with observed cases.
[0029] Ordinal categorical variables were analyzed by the Wilcoxon rank-sum test. Nominal
categorical variables were analyzed using Fisher's exact or Pearson's chi-square tests.
Within-group changes from baseline for categorical variables were analyzed using the
Wilcoxon signed-rank test. Continuous variables (eg, IOP) were analyzed using analysis
of variance (ANOVA). Within-group changes from baseline for continuous variables were
analyzed using paired t-tests.
[0030] A 2-way ANOVA model with factors for treatment and investigator was used for the
analysis of IOP. Comparisons were made between the Combination and each of the 2 monotherapies
in a pairwise fashion using contrasts from the ANOVA model, with the same error term.
A separate ANOVA model was employed at each hour/visit measurement of IOP. Each of
the 2 null hypotheses (Combination versus Timolol and Combination versus Brimonidine)
was tested at the 0.05 significance level. Point estimates of the mean treatment differences,
as well as 2-sided 95% confidence intervals (CI) of the difference, were provided
at each timepoint.
Summary - Conclusions:
Efficacy:
[0031] At baseline, mean values of diurnal IOP ranged from 22.2 mm Hg to 24.9 mm Hg in the
Combination group, 22.5 mm Hg to 25.0 mm Hg in the Brimonidine group, and 22.3 mm
Hg to 24.8 mm Hg in the Timolol group. There were no statistically significant differences
between treatment groups.
[0032] Mean changes from baseline diurnal IOP at week 2, week 6 and month 3 ranged from:
-5.2 to -7.9 mm Hg in the Combination group
-3.5 to -5.7 mm Hg in the Brimonidine group
-4.5 to -6.4 mm Hg in the Timolol group
[0033] The mean decreases from baseline diurnal IOP were statistically significant within
each treatment group at each follow-up timepoint (p < 0.001).
[0034] The mean decrease from baseline diurnal IOP was statistically significantly greater
with Combination than with Brimonidine at hours 0, 2, and 7 at all follow-up visits
(p < 0.001). In addition, clinically significant differences of more than 1.5 mm Hg
in mean change from baseline IOP favoring Combination over Brimonidine were seen at
hours 0, 2, and 7 at all follow-up visits. At hour 9, the decreases from baseline
diurnal IOP were greater for the Combination group than the Brimonidine group at all
follow-up visits, although the differences were not statistically significant (p ≥
0.104).
[0035] The mean decrease from baseline diurnal IOP was statistically significantly greater
with Combination than with Timolol at hours 0, 2, 7 and 9 at all follow-up visits
(p ≤ 0.041). In addition, clinically significant differences of more than 1.5 mm Hg
in mean change from baseline IOP favoring Combination over Timolol were seen at week
2 (hours 0, 2, and 7), week 6 (hours 2 and 7), and month 3 (hours 0 and 2). Mean values
of diurnal IOP at week 2, week 6 and month 3 ranged from:
15.9 to 18.1 mm Hg in the Combination group
17.4 to 21.5 mm Hg in the Brimonidine group
17.5 to 18.9 mm Hg in the Timolol group
[0036] Mean values of diurnal IOP were statistically significantly less with Combination
than with Brimonidine at hours 0, 2, and 7 at all follow-up visits (p < 0.001) and
at hour 9 at week 6 and month 3 (p ≤ 0.011). The mean values of IOP at hour 9 at week
2 were lower for the Combination group than the Brimonidine group, although the difference
was not statistically significant (p = 0.205). In addition, clinically significant
differences of more than 1.5 mm Hg in mean IOP favoring Combination over Brimonidine
were seen at hours 0, 2, and 7 at all follow-up visits and at hour 9 at month 3.
[0037] Mean values of diurnal IOP were statistically significantly less with Combination
than with Timolol at hour 0 at week 2 and month 3; and at hours 2, 7 and 9 at all
follow-up visits (p ≤ 0.050). The mean values of IOP at hour 0, week 6, were lower
for the Combination group than the Timolol group, although the difference was not
statistically significant (p = 0.102). In addition, clinically significant differences
of more than 1.5 mm Hg in mean IOP favoring Combination over Timolol were seen at
week 2 (hours 0, 2, and 7), week 6 (hours 2, 7, and 9), and month 3 (hours 2 and 9).
[0038] At the month 3 or exit visit, a statistically significantly greater "yes" response
to the Investigator Pharmacoeconomic Evaluation was recorded for patients receiving
Combination (91.1%, 173/190) than for patients receiving Brimonidine (73.4%, 141/192,
p <0.001). A "yes" response was recorded for 92.7% (179/193) of patients receiving
Timolol. There were no statistically significant differences in the change from baseline
in treatment comfort between Combination and each of the monotherapy groups.
[0039] Treatment satisfaction was better than baseline for a statistically significantly
greater percentage of patients in the Combination group (23.4%, 36/154) than in the
Brimonidine group (13.2%, 20/151, p = 0.005). A total of 19.9% (30/151) of patients
in the Timolol group reported better treatment satisfaction than baseline.
Safety:
[0040] Through month 3 of the study, 53.4% (103/193) of patients in the Combination group,
61.7% (121/196) of the Brimonidine group, and 50.8% (100/197) of the Timolol group
experienced one or more adverse events, regardless of causality. The incidences of
oral dryness, eye pruritus, foreign body sensation and conjunctival folliculosis were
statistically significantly lower with the Combination than with Brimonidine (p ≤
0.034), while burning and stinging were statistically significantly higher with the
Combination than with Brimonidine (p ≤ 0.028). There were no statistically significant
differences in adverse events between the Combination and Timolol, except for a statistically
significantly higher incidence of eye discharge with the Combination (2.6%, 5/193)
compared to Timolol (0%, 0/197; p = 0.029). The most frequently reported adverse events
(> 3% in any treatment group) were as follows, tabulated by descending order in the
Combination group:
| |
Combination |
Brimonidine |
Timolol |
| Preferred Term |
N = 193 |
N = 196 |
N = 197 |
| burning sensation in eye |
23 (11.9%) |
11 (5.6%) |
25 (12.7%) |
| conjunctival hyperemia |
16 (8.3%) |
23 (11.7%) |
11 (5.6%) |
| stinging sensation eye |
13 (6.7%) |
4 (2.0%) |
11 (5.6%) |
| infection (body as a whole) |
11 (5.7%) |
6 (3.1%) |
8 (4.1%) |
| visual disturbance |
6 (3.1%) |
11 (5.6%) |
3 (1.5%) |
| epiphora |
5 (2.6%) |
8 (4.1%) |
3 (1.5%) |
| oral dryness |
4 (2.1%) |
19 (9.7%) |
1 (0.5%) |
| eye pruritus |
3 (1.6%) |
13 (6.6%) |
3 (1.5%) |
| allergic conjunctivitis |
3 (1.6%) |
7 (3.6%) |
0 (0.0%) |
| asthenia |
3 (1.6%) |
6 (3.1%) |
1 (0.5%) |
| foreign body sensation |
2 (1.0%) |
10 (5.1%) |
5 (2.5%) |
| conjunctival folliculosis |
2 (1.0%) |
9 (4.6%) |
1 (0.5%) |
| somnolence |
2 (1.0%) |
7 (3.6%) |
0 (0.0%) |
[0041] Adverse events led to the discontinuation of 3.6% (7/193) of patients in the Combination
group, similar to 3.0% (6/197) of patients in the Timolol group, and statistically
significantly less than 14.3% (28/196) of patients in the Brimonidine group (p < 0.001).
Serious adverse events were reported for 1.0% (2/193) of patients in the Combination
group, 2.0% (4/196) of patients in the Brimonidine group, and 2.0% (4/197) of patients
in the Timolol group. Two patients receiving Timolol had 4 serious adverse events
(emphysema in one patient; nausea, sweating, and tachycardia in the other patient)
which were considered possibly related to the study drug. There was 1 death in the
Brimonidine group, possibly due to complications from cardiac surgery, and not related
to study drug.
[0042] There were no clinically relevant differences between the Combination and either
of the individual components in the mean change from baseline to month 3 for any hematology,
chemistry, or urinalysis parameter. Statistically significant (p ≤ 0.048) within-group
changes from baseline were found, but were small and not clinically relevant.
[0043] Small but statistically significant (p ≤ 0.001) mean reductions in heart rate ranging
from -2.1 to -3.7 bpm were seen with the Combination, similar to Timolol. Small but
statistically significant (p≤0.003) mean reductions in blood pressure at hour 2 (postdose)
were seen with the Combination, similar to Brimonidine. These small changes in mean
heart rate and blood pressure were associated with clinical symptoms in only a few
patients.
[0044] Increases from baseline in the severity of conjunctival erythema and conjunctival
follicles on biomicroscopy were statistically significantly less with the Combination
than with Brimonidine (p ≤ 0.011). The majority of patients in each treatment group
showed less than a 2-line change from baseline visual acuity. There were no significant
between-group differences for changes in visual fields or cup/disc ratio.
Pharmacokinetics:
[0045] Blood samples were available for 55 patients in the Combination group, 49 patients
in the Brimonidine group, and 54 patients in the Timolol group. All samples were assayed
for both brimonidine (lower limit of quantitation [LLOQ] 5 pg/mL) and timolol (LLOQ
5 pg/mL). Plasma brimonidine and timolol concentrations were not quantifiable in all
but 1 sample on day 0, hour 0 for both Combination and the monotherapy treatment groups.
[0046] In the Combination group, mean ± standard deviation (SD) plasma brimonidine concentrations
1 hour postdose at week 2 and month 3 were 49.7 ± 36.1 and 52.8 ± 46.7 pg/mL, respectively.
In the Brimonidine group, mean ± SD plasma brimonidine concentrations at week 2 and
month 3 were 81.0 ± 63.8 and 78.6 ± 48.9 pg/mL, respectively. In the Combination group,
mean ± SD plasma timolol concentrations at week 2 and month 3 were 0.499 ± 0.327 and
0.586 ± 0.580 ng/mL, respectively. In the Timolol group, mean ± SD plasma timolol
concentrations at week 2 and month 3 were 0.950 ± 0.709 and 0.873 ± 0.516 ng/mL, respectively.
[0047] Plasma brimonidine and timolol concentrations 1 hour postdose were steady and did
not increase over the 3-month study duration. Brimonidine concentrations were 39%,
34% and 39% lower in the Combination group than in the monotherapy group at week 2
(p = 0.004), month 3 (p = 0.013), and month 12, respectively. Timolol concentrations
were 47% and 33% lower in the Combination group than in the monotherapy group at week
2 (p < 0.001) and month 3 (p = 0.011), respectively.
[0048] Timolol concentrations were also significantly lower in the combination treatment
group than in the Timolol monotherapy treatment group (p=0.0006). Timolol concentrations
were 49%, 32%, and 21% lower in the combination group than in the monotherapy group
at week 2, month 3, and month 12, respectively.
[0049] The plasma brimonidine concentration in males was statistically significantly lower
than in females for the Brimonidine group (37% lower at week 2 [p = 0.034] and 37%
lower at month 3 [p = 0.017]); the difference was not statistically significant in
the Combination group. The plasma timolol concentration in males was statistically
significantly lower than in females for both the Combination group (not statistically
significant at week 2; 52% lower at month 3 [p = 0.012]) and the Timolol group (45%
lower at week 2 [p = 0.006] and 39% lower at month 3 [p= 0.003]).
[0050] Plasma brimonidine concentration in the elderly group was not significantly different
from in the young group for the combined data from both the combination and Brimonidine
treatment groups (p-value=0.1323). However, plasma timolol concentration in the young
group was significantly lower than in the elderly group for combined data from both
the combination and the Timolol treatment groups (p-value=0.0005).
Conclusions:
[0051] The Combination treatment (brimonidine tartrate 0.2%/timolol 0.5%) administered BID
for 3 months was superior to Timolol (timolol 0.5%) BID and Brimonidine (brimonidine
tartrate 0.2%) TID in lowering the elevated IOP of patients with glaucoma or ocular
hypertension. The Combination administered BID demonstrated a favorable safety profile
that was comparable to Timolol BID and better than Brimonidine TID with regard to
the incidence of adverse events and discontinuations due to adverse events.