Efficacy and tolerability of fixed combination of brimonidine 0.2%/timolol 0.5% compared with fixed combination of dorzolamide 2%/timolol 0.5% in the treatment of patients with elevated intraocular pressure: a meta-analysis of randomized controlled trials

Dorzolamide/Timolol Fixed Combination: Learning from the Past and Looking Toward the Future

The key clinical attributes of preserved dorzolamide/timolol fixed combination (DTFC) and the emerging potential of preservative-free (PF) DTFC are reviewed with published evidence and clinical experience. The indications and role of DTFC in current glaucoma management are critically discussed. Preserved DTFC became the first intraocular pressure (IOP)-lowering fixed combination (FC) approved by the US Food and Drug Administration (FDA) and remains one of most commonly used medications worldwide. The pharmacological properties of DTFC reflect those of its two time-tested constituents, i.e., the carbonic anhydrase inhibitor dorzolamide and the non-selective beta-blocker timolol. In regulatory studies DTFC lowers IOP on average by 9 mmHg (32.7%) at peak and by 7.7 mmHg (27%) at trough. In trials DTFC shows equivalence to unfixed concomitant therapy, but in real-life practice it may prove superior owing to enhanced convenience, elimination of the washout effect from the second drop, improved tolerability, and better adherence. PF DTFC became the first PF FC approved, first in unit-dose pipettes, and more recently in a multidose format. Cumulative evidence has confirmed that PF DTFC is at least equivalent in efficacy to preserved DTFC and provides a tangible clinical benefit to patients with glaucoma suffering from ocular surface disease by improving tolerability and adherence. Finally, we identify areas that warrant further investigation with preserved and PF DTFC

A Phase III Randomized Clinical Trial of a 0.5% Timolol + 0.2% Brimonidine + 2.0% Dorzolamide Fixed Combination, Preservative-Free Ophthalmic Solution vs. 0.5% Timolol + 0.2% Brimonidine + 2.0% Dorzolamide Fixed Combination in Patients with Controlled Primary Open-Angle Glaucoma

Introduction

The aim of this prospective crossover study was to evaluate the non-inferiority of PRO-122 (a preservative-free fixed combination) compared with 0.5% timolol + 0.2% brimonidine + 2.0% dorzolamide fixed combination (KOF) by evaluating its efficacy, tolerability and safety in subjects with controlled primary open-angle glaucoma (POAG) previously treated with KOF for at least 2 months.

Methods

In a prospective, crossover, randomized, double-masked multicenter study, patients previously treated with KOF were randomly assigned to receive either PRO-122 or KOF for 30 days. On day 31, the A sequence changed to KOF, while the B sequence received PRO-122. All patients remained in the protocol for 30 additional days for a total of 60 days. The main efficacy endpoint was maintaining the controlled intraocular pressure (IOP). The safety and tolerability of both products were assessed by the presence of adverse events (AEs), ocular findings, a questionnaire on ocular comfort and the VF-14 index.

Results

A total of 51 patients participated. After application of PRO-122 twice a day, its efficacy was demonstrated through maintenance of the controlled IOP in patients previously controlled with KOF. The crossover between PRO-122 and KOF and vice versa, after 30 days of use, did not affect IOP control. PRO-122 was shown not to be inferior to KOF in maintaining IOP at control levels. The safety of both drugs is similar, as neither presented drug-related AEs or differences regarding safety issues. The tolerability of the two medications—evaluated by ocular findings, the questionnaire on ocular comfort and the VF-14 index—was also determined to be similar.

Conclusions

The controlled IOP in patients with controlled POAG treated with PRO-122 was maintained both in relation to the initial controlled IOP of the study and when compared with KOF in the B sequence. Finally, the treatment with PRO-122 demonstrated similar safety and tolerability to KOF.

Funding

Laboratorios Sophia, S.A. de C.V. (Zapopan, Jalisco, México).

Trial Registration

ClinicalTrials.gov identifier: NCT03257813 (registered retrospectively).