A systematic review of the characteristics of randomised control trials featuring prostaglandins for the treatment of glaucoma

Preparation and Chiral HPLC Separation of the Enantiomeric Forms of Natural Prostaglandins

Four enantiomeric forms of natural prostaglandins, ent-PGF2α ((−)-1), ent-PGE2 ((+)-2) ent-PGF1α ((−)-3), and ent-PGE1 ((+)-4) have been synthetized in gram scale by Corey synthesis used in the prostaglandin plants of CHINOIN, Budapest. Chiral HPLC methods have been developed to separate the enantiomeric pairs. Enantiomers of natural prostaglandins can be used as analytical standards to verify the enantiopurity of synthetic prostaglandins, or as biomarkers to study oxidation processes in vivo.

Does the intraocular pressure-lowering effect of prostaglandin analogues continue over the long term?

The purpose of the study is to assess the changes in the long-term effects of prostaglandin analogues (PGAs) on intraocular pressure (IOP) reduction in patients with primary open-angle glaucoma (POAG). Data of POAG patients treated with latanoprost (0.005 %), travoprost (0.004 %), or bimatoprost (0.03 %) as the first line treatment for 5 years or more were retrospectively evaluated. Baseline ophthalmic assessment values were recorded together with the IOP at the 6th month, 1st year, and then annually. The 79 patients included 33 (41.8 %) men and 46 (58.2 %) women. There were 34 (43.0 %) patients using latanoprost (0.005 %), 23 (29.1 %) patients using bimatoprost (0.03 %), and 22 (27.8 %) patients using travoprost (0.004 %). There was no difference between the groups in terms of age, gender, or baseline IOP levels. IOP levels at the 6th month were significantly lower than baseline IOP levels in all groups (p < 0.01, Friedman test). The IOP decrease was maintained after the 6th month in all three group with no statistically significant difference compared to the 6th month IOP value (p > 0.05, Friedman test) and no statistically significant difference between the groups during follow-up (Kruskal-Wallis test, p > 0.05). IOP reductions with PGAs were adequate and stable in the 5-year follow-up period with no decrease in effectiveness over time.

Preservative-free versus preserved latanoprost eye drops in patients with open-angle glaucoma or ocular hypertension

OBJECTIVE

This study compared the efficacy, safety, and pharmacokinetics of a preservative-free latanoprost formulation to an established, benzalkonium chloride (BAK) containing formulation for the treatment of open-angle glaucoma or ocular hypertension.

METHODS

This was a phase II, randomized, cross-over, investigator-masked, multi-center, pilot study (NCT01494753). A total of 30 untreated adult patients (aged ≥18 years) with primary open angle glaucoma, pseudo-exfoliative glaucoma, pigmentary glaucoma, or ocular hypertension received either preservative-free or preserved latanoprost once daily in both eyes for 6 weeks, before crossing over to receive the other treatment. Efficacy (intraocular pressure [IOP] at 8 am, midday, 4 pm and 8 pm, and global efficacy assessment by investigator), safety (adverse events, ocular symptoms and global tolerance, slit lamp examination, funduscopy, visual field examination, visual acuity, and heart rate), and pharmacokinetics were assessed at Days 0, 42, and 84.

RESULTS

Both treatments resulted in a reduction in IOP that was similar for the preservative-free and the preserved formulation at all time points. Similarly, the overall diurnal reduction was similar in both groups (6.3 mmHg [27.9% reduction] and 6.4 mmHg [28.1% reduction] for preserved and preservative-free latanoprost, respectively). There were no differences in global efficacy assessment or in the safety and tolerance of each treatment. Systemic concentrations of latanoprost were very low; AUC0-30 and Cmax were lower and tmax was longer for preservative-free latanoprost.

CONCLUSIONS

Preservative-free latanoprost showed similar efficacy at all time points compared to BAK preservative containing formulation, with no difference in tolerance, allowing progression to phase III clinical development.

Efficacy and safety of tafluprost 0.0015% versus latanoprost 0.005% eye drops in open-angle glaucoma and ocular hypertension: 24-month results of a randomized, double-masked phase III study

PURPOSE

The objective of the study was to compare the long-term efficacy and safety of tafluprost 0.0015% with latanoprost 0.005% eye drops in patients with open-angle glaucoma or ocular hypertension.

METHODS

This double-masked, active-controlled, parallel-group, multinational, multicentre, phase III study was conducted at 49 centres in 8 countries. Eligible patients were assigned to treatment administered once daily at 20:00 hrs for up to 24 months. Change from baseline intraocular pressure (IOP) was the primary efficacy variable. Adverse events were recorded and ocular safety was evaluated. Both tafluprost and latanoprost were preserved with benzalkonium chloride.

RESULTS

From 533 patients randomized, 402 patients completed 24 months of therapy. Both treatments had a substantial IOP-lowering effect which persisted throughout the study (-7.1 mmHg for tafluprost and -7.7 mmHg for latanoprost at 24 months). Although the IOP-lowering effect during the study was slightly larger with latanoprost, this difference was clinically small and the noninferiority of tafluprost to latanoprost over all diurnal IOP measurements was shown with anova and almost reached with ancova (upper limits of the 95% confidence intervals 1.38 and 1.52 for the overall period, respectively). The noninferiority limit was 1.5 mmHg.

CONCLUSIONS

Tafluprost is a new effective and well-tolerated treatment for glaucoma and ocular hypertension.

New prostaglandin derivative for glaucoma treatment

A hydrogen sulphide-releasing derivative of latanoprost acid (ACS 67) was synthesized and tested in vivo to evaluate its activity on reduction of intraocular pressure and tolerability. Glutathione (GSH) and cGMP content were also measured in the aqueous humour. The increased reduction of intraocular pressure, with a marked increase of GSH and cGMP and the related potential neuroprotective properties, make this compound interesting for the treatment of glaucoma. This is the first time that an application of a hydrogen sulphide-releasing molecule is reported for the treatment of ocular diseases.

The effect of the Rho-associated protein kinase inhibitor, HA-1077, in the rabbit ocular hypertension model induced by water loading

PURPOSE

The aim of this study was to investigate the intraocular pressure (IOP)-lowering effect of a new anti-glaucoma drug, the Rho-associated protein kinase (ROCK) inhibitor, HA-1077, in a rabbit ocular hypertension model.

METHODS

Experiments were carried out in 18 male New Zealand white rabbits, with ocular hypertension induced by water loading. Animals were divided into three groups followed by topical administration of 1 mM, 2 mM, and 3 mM HA-1077 in the left eye. As a control, phosphate buffered saline was administered in the opposite eye.

RESULTS

After administration of HA-1077 eye drops, there was a significant time- and dose-dependent decrease of the IOP. While minor conjunctival injection was seen in a few cases, no abnormalities of the anterior chamber or fundus were observed.

CONCLUSIONS

This is the first report of the effect of the ROCK inhibitor, HA-1077, on the IOP in an ocular hypertension model. Study results indicated that HA-1077 has a strong IOP-lowering effect.