Concomitant administration of travoprost and brinzolamide versus fixed latanoprost/timolol combined therapy: three-month comparison of efficacy and safety

The Efficacy and Safety of Timolol Maleate versus Brinzolamide Each Given Twice Daily Added to Travoprost in Patients with Ocular Hypertension or Primary Open-Angle Glaucoma

PURPOSE

To compare the efficacy and safety of timolol maleate 0.5% versus brinzolamide 1% when added to travoprost 0.004% in patients with ocular hypertension or primary open-angle glaucoma.

DESIGN

A prospective, double-masked, randomized, active-controlled, parallel comparison.

METHODS

Qualified patients at Visit 1 were placed on travoprost dosed every evening for 4 weeks and then were randomized at baseline (Visit 2) to the addition of timolol maleate or brinzolamide each given twice daily. Patients returned to clinic at Week 4 (Visit 3) for a safety visit and Week 12 (Visit 4) for an efficacy visit. At Visits 2 and 4 the intraocular pressure (IOP) was measured at 08:00, 12:00, and 16:00 hours.

RESULTS

Ninety-seven patients on brinzolamide had a baseline diurnal IOP of 21.5+/-2.2 mmHg and 95 on timolol maleate had 21.3+/-2.5 mmHg, each added to travoprost. The diurnal mean IOP at Week 12 was 18.1+/-2.7 mmHg for brinzolamide and 18.1+/-3.0 mmHg for timolol maleate (p=0.96). There was no statistical difference found between treatment groups in the absolute level of pressure, or in the reduction in IOP from baseline, at each time point or for the diurnal curve (p>0.05). There was no significant difference for any adverse event between groups (p>0.05), with the most common side effect being conjunctival hyperemia in 15/97 (16%) brinzolamide and 6/95 (6%) timolol treated patients (p=0.06).

CONCLUSIONS

This study showed that brinzolamide provides similar safety and efficacy compared to timolol maleate when added to travoprost.

Long-term medical management of primary open-angle glaucoma and ocular hypertension in the UK: optimizing cost-effectiveness and clinic resources by minimizing therapy switches

PURPOSE

The objective was to assess the long-term economic consequences of the medical management of glaucoma in the UK.

METHODS

The economic evaluation was conducted using the results from a 10-year Markov model based around 3 key triggers for a switch in medical therapy for glaucoma, namely: lack of tolerance (using hyperemia as a proxy); intraocular pressure (IOP) not meeting treatment benchmark; and glaucoma progression. Clinical data from a comprehensive systematic literature review and meta-analysis were used. Direct costs associated with glaucoma treatment are considered (at 2008/9 prices) from the perspective of the UK NHS as payer (outpatient/secondary care setting). Using this model, the economic consequences of 3 prostaglandin-based treatment sequences were compared.

RESULTS

Drug acquisition costs account for around 8% to 13% of the total cost of glaucoma and, if ophthalmologist visits are included, amount to approximately £0.80 to £0.90 per day of medical therapy. The total long-term costs of all prostaglandin strategies are similar because of a shift in resources: increased drug costs are offset by fewer clinic visits to instigate treatment switches, and by avoiding surgery or costs associated with managing low vision. Under the latanoprost-based strategy, patients would have longer intervals between the need to switch therapies, which is largely due to a reduction in hyperemia, seen as a proxy for tolerance. This leads to a delay in glaucoma progression of 12 to 13 months. For every 1000 clinic appointments, 719 patients can be managed for 1 year with a latanoprost-based strategy compared with 586 or 568 with a bimatoprost or travoprost-based strategy.

CONCLUSIONS

Drug acquisition costs are not a key driver of the total cost of glaucoma management and the cost of medical therapy is offset by avoiding the cost of managing low vision. Economic models of glaucoma should include the long-term consequences of treatment as these will affect cost-effectiveness. This analysis supports the hypothesis that the economic and clinical benefits can be optimized by minimizing therapy switches.

Intraocular pressure-lowering effects of commonly used fixed-combination drugs with timolol: a systematic review and meta-analysis

Background

The first goal of medical therapy in glaucoma is to reduce intraocular pressure (IOP), and the fixed-combination medications are needed to achieve sufficiently low target IOP. The aim of this systematic review and meta-analysis is to evaluate IOP-lowering effect of the commonly used fixed-combination drugs containing 0.5% timolol.

Methods

Pertinent publications were identified through systematic searches. Over 85% of the patients had to be diagnosed with primary open-angle glaucoma (POAG) or ocular hypertension (OHT). Forty-one randomized clinical trials were included in the meta-analysis. The main efficacy measures were the absolute and relative values of mean diurnal IOP reduction, and the highest and lowest IOP reductions on the diurnal IOP curve. The pooled 1- to 3-month IOP-lowering effects after a medicine-free washout period was calculated by performing meta-analysis using the random effects model, and relative treatment effects among different fixed combinations were assessed using a mixed-effects meta-regression model.

Results

The relative reductions for mean diurnal IOP were 34.9% for travoprost/timolol, 34.3% for bimatoprost/timolol, 33.9% for latanoprost/timolol, 32.7% for brinzolamide/timolol, 29.9% for dorzolamide/timolol, and 28.1% for brimonidine/timolol. For the highest IOP decrease, relative reductions ranged from 31.3% for dorzolamide/timolol to 35.5% for travoprost/timolol; for the lowest IOP decrease, those varied from 25.9% for dorzolamide/timolol to 33.1% for bimatoprost/timolol. Both latanoprost/timolol and travoprost/timolol were more effective in lowering mean diurnal IOP than brimonidine/timolol (WMD: 5.9 and 7.0) and dorzolamide/timolol (WMD: 3.8 and 3.3).

Conclusions

All six commonly used fixed-combination drugs containing timolol can effectively lower IOP in patients with POAG and OHT, and both latanoprost/timolol and travoprost/timolol might achieve better IOP-lowering effects among the six fixed-combination agents.

[Adjunctive therapy with brinzolamide in patients on travoprost treatment]

INTRODUCTION

This study was aimed at evaluating the safety and efficacy of brinzolamide 1% suspension (Azopt 1%) and travoprost 0.004% (Travatan) combined therapy in patients with open-angle glaucoma or ocular hypertension who are in need of additional intraocular pressure lowering.

MATERIAL AND METHODS

This is a prospective, three-month, open-label, clinical study. Forty patients (80 eyes) with primary open-angle glaucoma or ocular hypertension on Travatan treatment and with unsatisfactory results in lowering intraocular pressure were included in the study. The qualifying intraocular pressure on previous treatment with Travatan (at least 6 weeks) was 22-36 mmHg in at least one eye at 8 a.m. intraocular pressure measurements at three eligibility visits. The patients received brinzolamide 1% twice a day in addition to travoprost 0.004% given once a day in the evening for 3 months. The follow-up examinations assessing the safety and efficacy of combined therapy of brinzolamide 1% and travoprost 0.004% were performed after 1 and 3 months.

RESULTS

Adjunctive therapy with brinzolamide resulted in statistically significant reductions in intraocular pressure from the travoprost baseline at all visits. Treatment with brinzolamide/travoprost caused statistically significant sustained reduction in intraocular pressure with the reduction of 17.39% (p < 0.001) after 4 weeks and 20.08% (p < 0.001) after 12 weeks. The intraocular pressure change from the baseline ranged from -3.9 mmHg after 4 weeks to -4.48 mmHg after 12 weeks. The most frequently related adverse effect was abnormal taste and blurred vision.

CONCLUSION

Brinzolamide 1% (b.i.d) used adjunctively with travoprost 0.004% (q.d.) lowers intraocular pressure significantly compared to travoprost alone. Both drugs were well tolerated and safe in the studied patients.

Mixed treatment comparison of repeated measurements of a continuous endpoint: an example using topical treatments for primary open-angle glaucoma and ocular hypertension

Mixed treatment comparison (MTC) meta-analyses estimate relative treatment effects from networks of evidence while preserving randomisation. We extend the MTC framework to allow for repeated measurements of a continuous endpoint that varies over time. We used, as a case study, a systematic review and meta-analysis of intraocular pressure (IOP) measurements from randomised controlled trials evaluating topical ocular hypotensives in primary open-angle glaucoma or ocular hypertension because IOP varies over the day and over the treatment course, and repeated measurements are frequently reported. We adopted models for conducting MTC in WinBUGS (The BUGS Project, Cambridge, UK) to allow for repeated IOP measurements and to impute missing standard deviations of the raw data using the predictive distribution from observations with standard deviations. A flexible model with an unconstrained baseline for IOP variations over time and time-invariant random treatment effects fitted the data well. We also adopted repeated measures models to allow for class effects; assuming treatment effects to be exchangeable within classes slightly improved model fit but could bias estimated treatment effects if exchangeability assumptions were not valid. We enabled all timepoints to be included in the analysis, allowing for repeated measures to increase precision around treatment effects and avoid bias associated with selecting timepoints for meta-analysis.The methods we developed for modelling repeated measures and allowing for missing data may be adapted for use in other MTC meta-analyses.

Brinzolamide ophthalmic suspension: a review of its pharmacology and use in the treatment of open angle glaucoma and ocular hypertension

Brinzolamide is a white powder commercially formulated as a 1% ophthalmic suspension to reduce intraocular pressure (IOP). Pharmacologically, brinzolamide is a highly specific, non-competitive, reversible, and effective inhibitor of carbonic anhydrase II (CA-II), able to suppress formation of aqueous humor in the eye and thus to decrease IOP. Several clinical trials have evaluated its safety and the most commonly ocular adverse events are blurred vision (3%-8%), ocular discomfort (1.8%-5.9%), and eye pain (0.7%-4.0%). Brinzolamide has been introduced to treat ocular hypertension and primary open-angle glaucoma. In some clinical studies it has been estimated that brinzolamide reduced IOP by was about 18%. Brinzolamide can be added to beta-blockers and prostaglandins. In the latter combination, because prostaglandin derivatives improve the uveoscleral outflow but also increase the activity of CA in ciliary epithelium with a secondary increase in aqueous humor secretion, and slightly reduce the efficacy of prostaglandin analogues, theoretically topical CA inhibitors (CAI) decrease IOP by inhibiting CA-II, thus improving prostaglandin efficacy as well as lowering IOP. Brinzolamide could have a secondary possible effect on ocular flow too. Some clinical studies showed a mild improvement of ocular blood flow. Theoretically, CAI could give rise to metabolic acidosis, with secondary vasodilatation and improvement of blood flow. Systemic acidosis can occur in the setting of oral CAI therapy, and local acidosis within ocular tissues is theoretically possible with topical CAI therapy, with the potential for a local increase in ocular blood flow. In conclusion, topical CAI treatment has efficacy in IOP-lowering ranging from 15% to 20%. From published data, brinzolamide can be used as first-line medication, even if other medications have a higher efficacy, with few side effects and it is a good adjunctive treatment. In some type of glaucoma patients with a vascular dysregulation, topical CAI could have a double effect: reducing IOP and improving ocular blood flow.

Mixed treatment comparison and meta-regression of the efficacy and safety of prostaglandin analogues and comparators for primary open-angle glaucoma and ocular hypertension

OBJECTIVES

Primary open-angle glaucoma (POAG) is a chronic condition characterised by optic neuropathy and vision loss. Elevated intraocular pressure (IOP) can damage the optic nerve and is a risk factor for glaucoma, thus treatment usually comprises topical hypotensives. This analysis aims to address methodological issues associated with the synthesis of glaucoma clinical trial data, given variations in study methodology and IOP measurement.

METHODS

Meta-regression was used to estimate how IOP varies over time for patients receiving treatment. Relative treatment effects were assessed using a random-effects mixed treatment comparison (MTC) in order to preserve randomisation and avoid selection bias. To produce clinically meaningful outputs, these analyses were combined to obtain the mean on-treatment IOP and the proportion of patients achieving different IOP targets at different time points. A further MTC estimated the probability of hyperaemia events.

RESULTS

The analysis showed that after 3 months' treatment, between 58 and 83% of patients will have a > or =20% reduction in IOP and 70-93% of patients will have an absolute IOP <20 mmHg. Latanoprost and bimatoprost were found to produce significantly lower on-treatment IOP compared with timolol (p < 0.05); the difference between latanoprost and bimatoprost was not significant. Travoprost produced a lower mean IOP compared with timolol (not significant). Latanoprost-timolol was found to produce significantly lower IOP than latanoprost alone or beta-blockers. The probability of hyperaemia-type events varied between treatments from 14.8 to 63.03%. Latanoprost had significantly lower odds of hyperaemia than travoprost, bimatoprost, travoprost-timolol, or bimatoprost-timolol.

CONCLUSION

This analysis suggests that latanoprost and bimatoprost produce a statistically significant reduction in IOP compared with timolol, but are associated with a higher risk of hyperaemia. Out of all the prostaglandins, latanoprost may achieve a good balance between tolerability and IOP efficacy. As with all forms of meta-analysis, the results are based on the assumption that the studies and intervention groupings are sufficiently similar to be compared.

Effects of brinzolamide vs timolol as an adjunctive medication to latanoprost on circadian intraocular pressure control in primary open-angle glaucoma Japanese patients

Purpose

To study the effect of the concomitant use of brinzolamide and latanoprost on the 24-hour variation in intraocular pressure (IOP) in primary open-angle glaucoma (POAG) patients first treated with timolol and latanoprost.

Methods

We studied 30 eyes from 30 POAG patients previously treated with latanoprost monotherapy. After a washout of four weeks in both eyes, all patients were treated with 0.5% timolol and latanoprost. Three months after the initiation of treatment with timolol and latanoprost, the 24-hour IOP variation was measured. Thereafter, all patients were treated with concomitant 1% brinzolamide and latanoprost. Three months after changing the therapeutic regimen, the 24-hour IOP variation was measured a second time. Latanoprost was administered once a day, and timolol and brinzolamide were twice a day. IOP was measured with a noncontact tomometer.

Results

On treatment with brinzolamide and latanoprost, a significant decrease in IOP compared to timolol and latanoprost was observed at all time points except at 3 PM and 6 PM. As a group, the patients had a significantly lower diurnal mean IOP and nocturnal mean IOP during treatment with brinzolamide and latanoprost than with timolol and latanoprost.

Conclusions

Treatment of POAG with a combination of brinzolamide and latanoprost demonstrated improved hypotensive effects compared with timolol and latanoprost during a 24-hour period.

Efficacy and safety of combination therapy with latanoprost after a change in therapeutic regimen from timolol to brinzolamide in Japanese adult patients with primary open-angle glaucoma and ocular hypertension: open, non-randomized 12-week study

Purpose

To compare the efficacy of brinzolamide in Japanese patients with primary open-angle glaucoma (POAG) or ocular hypertension (OH) after a change from timolol in combination therapy with latanoprost.

Methods

A 12-week, prospective, open-label, comparative study was performed in 20 patients [11 males and 9 females, mean age of 64.5 ± 11.0 (SD)y] with POAG or OH treated with both latanoprost once daily and timolol 0.5% twice daily. During the study brinzolamide was substituted for timolol. Intraocular pressure (IOP) was measured at baseline, 4, 8, and 12 weeks. Blood pressure (BP), pulse rate (PR), and adverse events were also recorded.

Results

IOPs at baseline, 4, 8, and 12 weeks were 18.6 ± 2.1 mmHg, 17.8 ± 2.6 mmHg, 17.4 ± 2.5 mmHg, and 17.3 ± 3.5 mmHg, respectively. IOP reduction at 4 and 8 weeks was statistically significant (p < 0.05). The PR was significantly increased at 12 weeks (p < 0.01), but BP was not significantly affected. Four ocular adverse events were noted, but all were mild and transient.

Conclusions

Substituting brinzolamide 1% for timolol 0.5% in combination therapy with latanoprost 0.005% demonstrated significant IOP reduction with improvement in PR with POAG or OH. Combination therapy using latanoprost and brinzolamide may be recommended for better IOP control with fewer systemic adverse events.

Effect of Concomitant Use of Latanoprost and Brinzolamide on 24-hour Variation of IOP in Normal-tension Glaucoma

PURPOSE

To study the effect of the concomitant use of latanoprost and brinzolamide on the 24-hour variation in the intraocular pressure (IOP) in patients with normal-tension glaucoma (NTG).

METHODS

We studied a total of 44 eyes from 22 NTG patients. Mean 24-hour IOP variation was determined after a washout period of > or =4 weeks. Latanoprost monotherapy was continued in both eyes for 8 weeks. Thereafter, patients were randomized to continue latanoprost monotherapy in 1 eye whereas brinzolamide was added as an adjunct to latanoprost therapy in the other eye. Eight weeks after the initiation of brinzolamide treatment, the 24-hour IOP variation was remeasured. IOP was measured in the sitting position 8 times daily using a Goldmann applanation tonometer before and after treatment.

RESULTS

The eyes treated with latanoprost monotherapy and those treated with latanoprost and brinzolamide showed a significant decrease in IOP at all time points. Percent reductions in the diurnal mean IOP (mean IOP at 10 AM, 1 PM, and 4 PM) and in nocturnal mean IOP (mean IOP at 10 PM, 1 AM, and 3 AM) were significantly greater in the eyes treated with the combination of latanoprost and brinzolamide than those with latanoprost alone (diurnal mean IOP: latanoprost and brinzolamide=19.8%, latanoprost=14.1%, P<0.001; nocturnal mean IOP: latanoprost and brinzolamide=13.4%, latanoprost=10.0%, P<0.05).

CONCLUSIONS

For the treatment of NTG, the combination of latanoprost and brinzolamide demonstrated additive effects in lowering IOP, not only during the day, but also at night.

Relationship between travoprost and central corneal thickness in ocular hypertension and open-angle glaucoma

PURPOSE

To evaluate whether treatment with travoprost, an F2a prostaglandin analog, affects central corneal thickness (CCT) and whether intraocular pressure (IOP) response to the medication is related to baseline CCT.

METHODS

This was a prospective, interventional, nonrandomized, nonconsecutive, clinical trial. In this multicenter study, 379 total patients, 220 with newly or previously diagnosed open-angle glaucoma (OAG), 141 with ocular hypertension (OHT), and 18 unspecified, were recruited from 15 Canadian sites. IOP and CCT assessments were performed at baseline and 6 weeks after treatment with travoprost. Patients on IOP-lowering therapy at the time of enrollment were washed out for 4 weeks before baseline examinations. IOP was measured with Goldmann tonometers and CCT with Accutome IV pachymeters. Statistical analysis was performed with S-PLUS software.

RESULTS

Posttherapy mean IOP decreased by 6.31 mm Hg or 24.4% (P < 0.001), and regression analysis indicated relatively greater IOP reduction in patients with higher pretherapy IOP (slope = 0.64; 95% CI, 0.54-0.76). Mean CCT decreased by 6.9 microm (P < 0.001). IOP reduction was not related to CCT reduction (slope = 0.253; 95% CI, -0.232 to 0.739; P = 0.305). Percent IOP decrease was not related to baseline CCT (slope = -0.02; 95% CI, -0.06 to 00.02; P = 0.33) in the total study sample. When OHT and OAG groups were considered separately, the OAG patients had less percent IOP decrease with thicker baseline CCT (slope = -0.067; 95% CI, -0.13 to -0.004; P = 0.037).

CONCLUSIONS

Treatment with travoprost decreased IOP significantly and was associated with CCT thinning, which had little or no effect on actual IOP decrease. In the OAG group, IOP decrease was found to be statistically smaller in patients with thicker corneas.

Influence of switching to travoprost on intraocular pressure of uncontrolled chronic open-angle glaucoma patients compliant to previously-used topical medication

OBJECTIVE

To investigate the influence of switching to travoprost on intraocular pressure (IOP) of chronic open-angle glaucoma (COAG) patients.

RESEARCH DESIGN AND METHODS

Multicentre, open-label, non-comparative, 12-week, phase IV study conducted at 10 academic and hospital centres in Hungary. Patients' compliance to use of the pre-study medication was confirmed at a visit 10 days before the baseline measurements, and compliance was monitored throughout the study period.

RESULTS

Of the 203 COAG patients three (1.48%) ceased travoprost medication due to ocular hyperaemia, and one subject was lost from follow-up. Self-reported compliance was optimal except for two patients. For the per-protocol analysis 197 patients were evaluable. IOP of the 37 per-protocol patients receiving additional travoprost medication decreased from 23.1 +/- 3.2 mmHg (mean +/- SD) to 17.3 +/- 2.6 mmHg at week 12 (p < 0.001). Switching the 121 per-protocol patients from latanoprost to travoprost IOP decrease from 20.8 +/- 3.5 mmHg to 17.7 +/- 2.4 mmHg (p < 0.001). IOP of the 11 patients switched from topical nonselective beta-blockers to travoprost decreased from 20.1 +/- 2.1 mmHg to 15.7 +/- 1.5 mmHg (p < 0.001). For the whole per-protocol population (n = 197) IOP decreased from 21.0 +/- 3.4 mmHg to 17.4 +/- 2.4 mmHg (p < 0.001). Defining responders as having an IOP decrease > 2.0 mmHg or >or= 5 mmHg at week 12, the responder rate was respectively 62.9% or 31% for the total study population; 86.5% or 54.1% when travoprost was added to the established therapy; 54.5% or 24.0% if latanoprost was switched to travoprost; and 90.9% or 36.4% for those who switched from beta-blockers.

CONCLUSION

Travoprost provided a clinically and statistically significant IOP decrease in uncontrolled COAG patients whose self-reported compliance to their previous topical medication was optimal. Our results suggest that the IOP reduction found after switching to travoprost is not explainable by improved compliance due to the clinical study situation.

A 12-week, randomized, double-masked, multicenter study of the fixed combination of latanoprost and timolol in the evening versus the individual components

PURPOSE

To compare the efficacy and tolerability of fixed-combination latanoprost and timolol applied in the evening with the concomitant use of the individual components.

DESIGN

Twelve-week, randomized, double-masked, multicenter study.

PARTICIPANTS

Five hundred seventeen randomized patients with ocular hypertension; open-angle, pigmentary, or exfoliation glaucoma; and baseline (after washout) intraocular pressure (IOP) levels between 23 and 33 mmHg.

METHODS

Patients received either the fixed combination of latanoprost and timolol once daily in the evening and a placebo in the morning and evening or the unfixed combination of latanoprost once daily in the evening and timolol in the morning and evening. Study visits were at weeks 2, 6, and 12.

MAIN OUTCOME MEASURES

The primary efficacy end point was mean change from baseline to week 12 in diurnal IOP (mean IOPs of 8 am, 12 pm, and 4 pm). The fixed combination was considered noninferior to the unfixed combination if the upper limit of the 95% confidence interval (CI) of the difference was <1.5 mmHg (analysis of covariance). Adverse events were recorded at each visit.

RESULTS

In all, 502 patients were included in intent-to-treat analyses (fixed combination, n = 255; unfixed combination, n = 247). For the fixed- and unfixed-combination groups, mean baseline diurnal IOP levels were 25.4 mmHg and 25.2 mmHg, respectively, and mean diurnal IOP reductions were 8.7 mmHg and 9.0 mmHg (between-treatment difference, 0.3 mmHg; 95% CI, -0.1 to 0.7 mmHg; P = 0.15). Both treatments were well tolerated.

CONCLUSIONS

The fixed combination of latanoprost and timolol administered once daily in the evening is not inferior to the unfixed combination of latanoprost once daily in the evening and timolol twice daily. The fixed combination provides an effective and well-tolerated alternative to multiple instillations.