Sustainability of Intraocular Pressure Reduction of Travoprost Ophthalmic Solution in Subjects with Normal Tension Glaucoma

Sovesudil (locally acting rho kinase inhibitor) for the treatment of normal-tension glaucoma: the randomized phase II study

PURPOSE

To evaluate ocular hypotensive efficacy and the safety of sovesudil (formally known as PHP-201), a novel Rho-associated protein kinase (ROCK) inhibitor, in patients with normal-tension glaucoma (NTG).

DESIGN

Multicentre, prospective, double-masked, randomized, placebo-controlled, parallel clinical study.

METHODS

Patients with NTG (unmedicated baseline IOP ≤ 21 mmHg) were randomized in 3 groups and treated with sovesudil in concentrations of 0.25% and 0.5%, or with a placebo three times daily (TID) for 4 weeks. The primary end-point was the mean diurnal IOP change from the baseline at week 4. Safety was recorded over a 4-week treatment period and the following 2-week observation period.

RESULTS

A total of 119 patients were included in the primary efficacy analysis. The mean diurnal IOP change from the baseline at week 4 was -1.56 mmHg for the high-dose group, -1.10 mmHg for the low-dose group and -0.65 mmHg for the placebo group. The difference between the high-dose and the placebo groups was -0.91 mmHg (95% confidence intervals: -1.73, -0.09). 0.5% sovesudil TID met the criteria for superiority to the placebo. The most frequent ocular adverse event among sovesudil-treated patients was conjunctival hyperaemia (24.4% for the high-dose and 17.5% for the low-dose group) and predominately classified as mild.

CONCLUSIONS

Sovesudil 0.25% and 0.5% TID showed statistically significant IOP-lowering effects and 0.5% concentration's IOP-lowering effects met the superiority criteria in comparison with the placebo at week 4. Sovesudil was well tolerated with mild adverse events including relatively low incidence of conjunctival hyperaemia in patients with NTG.

Ocular hypotensive effects of prostaglandin analogs in Japanese patients with normal-tension glaucoma: a literature review

PURPOSE

This paper aimed to evaluate the intraocular pressure (IOP)-lowering effects of prostaglandin analogs (PGAs) in Japanese patients with normal-tension glaucoma (NTG) by reviewing the current literature.

METHODS

In February 2018, database searches were performed in PubMed, Embase, ProQuest, and the Japanese databases JAPICDOC and JMEDPlus. Studies were sorted into two categories: Category 1 consisted of studies of patients with NTG who reported reduced IOP values and Category 2 consisted of studies of patients with NTG who had IOP values at predosing and a final evaluation point. Search terms included ([unoprostone or latanoprost or travoprost or bimatoprost or tafluprost] and [glaucoma] and [Japan or Japanese]). The weighted ocular hypotensive efficacy was calculated. A scatter plot analysis was performed and a regression equation was calculated for each medication. The fitting of each regression equation was evaluated by the least squares method.

RESULTS

Eleven articles were eligible for Category 1 and 25 articles for Category 2. In the rank order of IOP-lowering efficacy of PGAs, bimatoprost was the strongest and latanoprost the weakest. Travoprost and tafluprost had almost the same level of ocular hypotensive effect, and both were stronger than latanoprost. The scatter plot analysis showed that all PGAs reduced IOP by 15%-20%. At higher IOP (17-18 mmHg), the ocular hypotensive effect was almost the same with latanoprost, travoprost, and tafluprost. In contrast, at lower IOP (12-15 mmHg), the IOP reduction with latanoprost was weaker than with travoprost or tafluprost.

CONCLUSION

This literature review of the ocular hypotensive effects of PGAs in Japanese patients with NTG highlighted that PGAs had different ocular hypotensive effects. Ophthalmologists should understand the IOP-lowering profiles of various PGAs and apply them to patients with NTG on a case-by-case basis.

TRIAL REGISTRATION

UMIN Clinical Trials Registry UMIN000032344.

Multicenter, Randomized, Investigator-Masked Study Comparing Brimonidine Tartrate 0.1% and Timolol Maleate 0.5% as Adjunctive Therapies to Prostaglandin Analogues in Normal-Tension Glaucoma

INTRODUCTION

This study compared the efficacy and safety of adjunctive brimonidine tartrate 0.1% ophthalmic solution (brimonidine) and timolol maleate 0.5% ophthalmic solution (timolol) in prostaglandin analogue (PGA)-treated normal-tension glaucoma (NTG), assessing the non-inferiority of brimonidine in terms of intraocular pressure (IOP) reduction.

METHODS

In this multicenter, randomized, investigator-masked, parallel-group, clinical study, adjunctive brimonidine or timolol was administered twice daily for 12 weeks in eyes with NTG that had been treated with PGA for at least 90 days and required additional treatment despite an IOP of 16 mmHg or less. IOP was measured on at least three visits before add-on therapy (mean baseline IOP), and at weeks 4, 8, and 12 after adjunctive administration. Systolic/diastolic blood pressure, pulse rate, and adverse events (AEs) were recorded at each visit.

RESULTS

A total of 152 individuals were enrolled and 128 (84.2%) were eligible for efficacy analyses. IOP in both groups at each visit decreased significantly from baseline (P < 0.001). However, the difference in the change from baseline IOP at week 12 between the brimonidine (-1.05 ± 1.81 mmHg) and timolol (-1.41 ± 1.40 mmHg) groups was 0.36 mmHg (95% confidence interval [CI] [-0.21, 0.92]), which exceeded the value of the non-inferiority margin (0.75 mmHg). Baseline systolic/diastolic blood pressure decreased significantly in both groups at certain visits (P < 0.05), while baseline pulse rates decreased significantly in the timolol group (P < 0.001), with no significant differences in the brimonidine group. AE-related treatment discontinuation occurred in 2/71 (2.8%) and 2/75 (2.7%) patients in the brimonidine and timolol groups, respectively.

CONCLUSION

This study demonstrated an add-on effect of brimonidine to PGAs, although non-inferiority of brimonidine to timolol as adjunctive therapy in PGA-treated NTG in terms of IOP reduction was not observed. Brimonidine was associated with no adverse effects on pulse rate.

FUNDING

Senju Pharmaceutical Co., Ltd.

TRIAL REGISTRATION

UMIN Clinical Trials Registry identifier, UMIN000014810.