Fixed combination netarsudil-latanoprost for the treatment of glaucoma and ocular hypertension

Rho-kinase Inhibitors in Ocular Diseases: A Translational Research Journey

Aim

This review summarizes current data on Rho-kinase (ROCK) inhibitors use in ocular diseases, primarily glaucoma.

Background

Translational research over the last decade culminating in the development of ROCK inhibitors has provided a much-needed shot in the arm to glaucoma pharmacopeia. ROCK pathway is intricately involved in cytoskeletal modulation with action on cell morphology, cell motility, cell adhesion, cell apoptosis, and smooth muscle contraction. This cytoskeletal modulation property has been utilized to modify trabecular meshwork (TM) resistance, resulting in the discovery of ROCK inhibitors to increase trabecular outflow.

Review results

Multicentric trials on ROCK inhibitors for antiglaucoma medications are summarized. The focus is on linking pharmacological action to the clinical utility of these drugs. While the Rho Kinase Elevated intraocular Pressure (IOP) Treatment (ROCKET) trials compared monotherapy with ROCK inhibitor netarsudil vs timolol, MERCURY trials compared a fixed dose combination of latanoprost and ROCK inhibitor netarsudil [fixed combination netarsudil-latanoprost (FCNL)] vs monotherapy with either and bimatoprost-timolol combination. While ROCKET trials showed ROCK inhibitors to be non-inferior to timolol, MERCURY trials showed FCNL achieving a much greater IOP reduction than monotherapy with either. Conjunctival hyperemia was the most common side effect reported with ROCK inhibitor use.

Conclusion

Moderate efficacy of ROCK inhibitors with a common side effect of conjunctival hyperemia, makes it an adjunctive antiglaucoma drug of choice and not a first-line therapy.

Clinical significance

ROCK inhibitors' action on diseased TM is more physiological compared to available antiglaucoma medications that either reduce aqueous secretion or enhance uveoscleral outflow. The property of ROCK inhibition to stabilize the endothelium of both retinal vasculature and cornea has opened a new chapter in the treatment of diabetic retinopathy and corneal decompensation.

How to cite this article

Singh K, Singh A. Rho-kinase Inhibitors in Ocular Diseases: A Translational Research Journey. J Curr Glaucoma Pract 2023;17(1):44-48.

A novel fixed-combination timolol-netarsudil-latanoprost ophthalmic solution for the treatment of glaucoma and ocular hypertension

Currently commercial fixed-concomitant three agents have multiple problems such as multiple dosing administration, poor efficacy and side effects. Once-daily fixed-combination timolol-netarsudil-latanoprost ophthalmic solution (FC-TNL) has the ability to treat glaucoma by lowering the intraocular pressure (IOP) with great efficacy and improving patient compliance. However, the commercialized netarsudil dimesylate precipitated when the pH of the solution was above 5.4, or when maleic acid, the salt of commercial timolol maleate, was mixed with netarsudil dimesylate. Consequently, the homologous salt engineering strategy was used to make netarsudil dimesylate soluble in pH 4.8-5.2 solution by synthesizing timolol mesylate. Next, the morphology of timolol mesylate was observed by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and powder X-ray diffraction. The prepared FC-TNL showed good stability during refrigeration storage. Additionally, FC-TNL exerted no influence on the intraocular penetration of each active compounds in the pharmacokinetic study. Importantly, once-daily FC-TNL exerted potent IOP-lowering effect and protective effect on retinal ganglion cells. The FC-TNL was stable, safe and effective, being a promising glaucoma therapeutic.

The use of fixed dose drug combinations for glaucoma in clinical settings: a retrospective, observational, single-centre study

BACKGROUND

The aim of study was to understand anti-glaucoma fixed dose drug combination use in real-world settings, focussing on drug selection, repeated prescription of the same active ingredient, and administration of fixed dose combinations, thus providing a reference for doctors during prescription and pharmacists during prescription review, ultimately educating patients on medication.

METHODS

A retrospective, observational, single-centre study was conducted. Outpatient prescriptions for anti-glaucoma eye drops from 01 January to 31 March 2021 were extracted. The prescriptions containing anti-glaucoma fixed dose combinations were analysed, and the rationale for each prescription was reviewed.

RESULTS

There were 10,947 ophthalmic patients with anti-glaucoma eye drop prescriptions in the study period. Of these, 4002 (36.5%) were prescribed anti-glaucoma fixed dose drug combinations. Approximately 80% of the patients were prescribed brinzolamide/timolol, while about 10% received prostaglandin analogues/timolol eye drops. Less than 40% of prescriptions were for monotherapy with fixed dose combinations. The most commonly duplicated drug class was β-receptor antagonists. An increase in prescribing drugs containing the same ingredient was observed for regimens containing various medicines.

CONCLUSION

More than 60% of the combinations were used together with other anti-glaucoma drugs. The advantages of these fixed dose combinations in improving patient compliance need to be reassessed in real-word settings. Prescriptions containing duplicated ingredients were common. However, they were not necessarily considered unreasonable because the dosage forms were administered at different times. For prescriptions containing repetitive ingredients, pharmacists should judge the rationale by evaluating the dosing frequency and drug indications and explain the appropriate administration to patients.

Prostanoid receptor agonists for glaucoma treatment

Intraocular pressure reduction is the only available and evidence-based medical therapy for glaucoma. Currently, the first-line eye drops are prostaglandin analogues including latanoprost, travoprost, bimatoprost, and tafluprost. These drugs stimulate intraocular prostanoid false positive (FP) receptors and reduce intraocular pressure by increasing mainly uveoscleral aqueous outflow. For 2 decades since latanoprost was launched, no drug has been comparable in its efficacy. In 2018, a prostanoid EP2 agonist, omidenepag, was launched in Japan. Current FP agonists and EP2 agonists indicate comparable intraocular pressure reduction by stimulating prostanoid FP or EP2 receptors. However, their safety profiles are quite different because of the differences between the intracellular signaling pathways through their own receptors. Including these commercially available FP and EP2 receptor agonists, prostanoid receptors have a large potential to control intraocular pressure. In this review I will trace the history and development of FP and EP2 receptor agonists from their original function, and explain their potential as first-line drugs including elucidation of their efficacy and safety.

Articular Chondrocyte Phenotype Regulation through the Cytoskeleton and the Signaling Processes That Originate from or Converge on the Cytoskeleton: Towards a Novel Understanding of the Intersection between Actin Dynamics and Chondrogenic Function

Numerous studies have assembled a complex picture, in which extracellular stimuli and intracellular signaling pathways modulate the chondrocyte phenotype. Because many diseases are mechanobiology-related, this review asked to what extent phenotype regulators control chondrocyte function through the cytoskeleton and cytoskeleton-regulating signaling processes. Such information would generate leverage for advanced articular cartilage repair. Serial passaging, pro-inflammatory cytokine signaling (TNF-α, IL-1α, IL-1β, IL-6, and IL-8), growth factors (TGF-α), and osteoarthritis not only induce dedifferentiation but also converge on RhoA/ROCK/Rac1/mDia1/mDia2/Cdc42 to promote actin polymerization/crosslinking for stress fiber (SF) formation. SF formation takes center stage in phenotype control, as both SF formation and SOX9 phosphorylation for COL2 expression are ROCK activity-dependent. Explaining how it is molecularly possible that dedifferentiation induces low COL2 expression but high SF formation, this review theorized that, in chondrocyte SOX9, phosphorylation by ROCK might effectively be sidelined in favor of other SF-promoting ROCK substrates, based on a differential ROCK affinity. In turn, actin depolymerization for redifferentiation would “free-up” ROCK to increase COL2 expression. Moreover, the actin cytoskeleton regulates COL1 expression, modulates COL2/aggrecan fragment generation, and mediates a fibrogenic/catabolic expression profile, highlighting that actin dynamics-regulating processes decisively control the chondrocyte phenotype. This suggests modulating the balance between actin polymerization/depolymerization for therapeutically controlling the chondrocyte phenotype.

Netarsudil for the Treatment of Open-Angle Glaucoma and Ocular Hypertension: A Literature Review

Objective:

To evaluate netarsudil’s role as first-line therapy for the treatment of open-angle glaucoma (OAG) and ocular hypertension (OHT).

Data Sources:

A literature search utilizing MEDLINE and CINAHL was performed using netarsudil and AR-13324 as keywords. Studies published from January 1970 to September 2020 were eligible.

Study Selection and Data Extraction:

For inclusion, articles were required to be published in English and participants enrolled in phase I, II, or III clinical trials. Articles were excluded if netarsudil was coformulated with another medication. Preclinical research, case reports, case series, review articles, citations without an abstract, and newsletters were excluded.

Literature Review:

The search retrieved 97 unique citations; 90 results were excluded, and 7 studies were included for analysis.

Relevance to Patient Care and Clinical Practice:

In all, 20 years elapsed between the Food and Drug Administration’s approvals of distinct medications to treat OAG. Existing first-line therapies target the uveoscleral pathway, which is responsible for a small amount of aqueous humor outflow. Rho kinase inhibitors target the trabecular pathway, which is responsible for 90% of aqueous humor outflow; thus, Rho kinase inhibitors may significantly reduce intraocular pressure and improve clinical outcomes for patients with OAG or OHT.

Conclusions:

Evidence demonstrates that netarsudil is inferior to prostaglandin analogues and noninferior to topical β-blockers in the treatment of OAG and OHT. Hyperemia is a common adverse drug reaction, which often resolves after medication discontinuation. Additional phase III clinical trials and evidence-based guidelines are necessary to determine netarsudil’s position in OAG and OHT management.