Effects of a Novel Selective EP2 Receptor Agonist, Omidenepag Isopropyl, on Aqueous Humor Dynamics in Laser-Induced Ocular Hypertensive Monkeys

Omidenepag Isopropyl 0.002% versus Latanoprost 0.005% in Open-Angle Glaucoma/Ocular Hypertension: The Randomized Phase III PEONY Trial

Purpose

To compare the efficacy and safety of omidenepag isopropyl (OMDI) 0.002% with latanoprost 0.005% once daily in Asian subjects with open-angle glaucoma (OAG)/ocular hypertension (OHT).

Methods

In this Phase III randomized, observer-masked, active-controlled, multinational trial (NCT02981446), subjects aged ≥18 years with OAG/OHT in both eyes and baseline intraocular pressure (IOP) ≥22 mmHg and ≤34 mmHg were randomized 1:1 to OMDI or latanoprost. IOP was measured at 9AM, 1PM, and 5PM at baseline, 1 week, 6 weeks, and 3 months. Adverse events (AEs) were recorded. Non-inferiority of OMDI to latanoprost was tested for primary and key secondary endpoints.

Results

Each group included 185 subjects. Mean diurnal IOP from baseline to month 3 was reduced 7.1 mmHg (28.8%) with OMDI and 7.8 mmHg (31.3%) with latanoprost, with the least-squares mean difference (OMDI minus latanoprost) being 0.6 mmHg (95% CI: 0.0, 1.2 mmHg; p = 0.0366), indicating non-inferiority. Mean IOP reductions at the nine timepoints were -5.8 to -7.3 mmHg (23.5-29.5%) for OMDI and -6.1 to -7.9 mmHg (24.3-31.7%) for latanoprost. Non-inferiority per FDA criteria was also met. Rates of all AEs, ocular AEs, and ocular AEs associated with treatment were 40.0%, 36.8%, and 23.2%, respectively, for OMDI and 29.7%, 21.1%, and 11.9%, respectively, for latanoprost. Conjunctival hyperemia rates were higher with OMDI than latanoprost (11.9% vs 5.4%). Most AEs were mild, with no serious ocular AEs.

Conclusion

OMDI safely and effectively reduces IOP in Asian subjects with OAG/OHT, with mean diurnal IOP at Month 3 and per-timepoint IOP reductions non-inferior to those of latanoprost.

Omidenepag Isopropyl Versus Timolol in Patients With Glaucoma or Ocular Hypertension: Two Randomized Phase 3 Trials (SPECTRUM 4 and 3)

PURPOSE

The SPECTRUM 4 and 3 studies assessed the intraocular pressure (IOP)-lowering efficacy and safety of omidenepag isopropyl (OMDI) 0.002% vs timolol 0.5% in patients with glaucoma or ocular hypertension (OHT).

DESIGN

Phase 3, randomized, controlled, double-masked, noninferiority studies.

METHODS

Multicenter studies in the US. Inclusion criteria for adults ≥ 18 years (SPECTRUM 4 [N = 409] and 3 [N = 413]) were open-angle glaucoma or OHT, and IOP ≥ 22 mm Hg and ≤ 34 mm Hg; and for pediatric patients < 18 years (N = 13, SPECTRUM 3) were pediatric glaucoma or OHT. The primary objective in both studies was OMDI noninferiority to timolol in reducing IOP (3 months). SPECTRUM 3 included an additional 9 months of OMDI treatment. Safety evaluations were of ocular/non-ocular adverse events (AEs).

RESULTS

The IOP-lowering range of OMDI remained consistent in SPECTRUM 4 and 3 (-5.6 to -5.9 vs -5.3 to -5.7 mm Hg, respectively); however, timolol efficacy varied (-5.4 to -6.1 vs -6.4 to -7.0 mm Hg, respectively). OMDI noninferiority was achieved in SPECTRUM 4. Efficacy was maintained with 12-month treatment in SPECTRUM 3. Both studies reported more ocular AEs with OMDI, but lower rates of appearance-altering AEs vs timolol. No new safety concerns were identified. Rates of macular edema in pseudophakic patients increased with prolonged OMDI exposure.

CONCLUSIONS

SPECTRUM 4 and 3 demonstrated consistent 3-month IOP-lowering efficacy and safety of OMDI vs timolol in patients with glaucoma or OHT. The 12-month data from SPECTRUM 3 suggest OMDI may have long-term benefits in patients with glaucoma or OHT.

Prodrugs as empowering tools in drug discovery and development: recent strategic applications of drug delivery solutions to mitigate challenges associated with lead compounds and drug candidates

The delivery of a drug to a specific organ or tissue at an efficacious concentration is the pharmacokinetic (PK) hallmark of promoting effective pharmacological action at a target site with an acceptable safety profile. Sub-optimal pharmaceutical or ADME profiles of drug candidates, which can often be a function of inherently poor physicochemical properties, pose significant challenges to drug discovery and development teams and may contribute to high compound attrition rates. Medicinal chemists have exploited prodrugs as an informed strategy to productively enhance the profiles of new chemical entities by optimizing the physicochemical, biopharmaceutical, and pharmacokinetic properties as well as selectively delivering a molecule to the site of action as a means of addressing a range of limitations. While discovery scientists have traditionally employed prodrugs to improve solubility and membrane permeability, the growing sophistication of prodrug technologies has enabled a significant expansion of their scope and applications as an empowering tool to mitigate a broad range of drug delivery challenges. Prodrugs have emerged as successful solutions to resolve non-linear exposure, inadequate exposure to support toxicological studies, pH-dependent absorption, high pill burden, formulation challenges, lack of feasibility of developing solid and liquid dosage forms, first-pass metabolism, high dosing frequency translating to reduced patient compliance and poor site-specific drug delivery. During the period 2012-2022, the US Food and Drug Administration (FDA) approved 50 prodrugs, which amounts to 13% of approved small molecule drugs, reflecting both the importance and success of implementing prodrug approaches in the pursuit of developing safe and effective drugs to address unmet medical needs.

Human experience and efficacy of omidenepag isopropyl (Eybelis®; Omlonti®): Discovery to approval of the novel non-prostaglandin EP2-receptor-selective agonist ocular hypotensive drug

More than 75 million people worldwide suffer from ocular hypertension (OHT)-associated retinal and optic nerve degenerative diseases that cause visual impairment and can lead to blindness. In an effort to find novel pharmaceutical therapeutics to combat OHT with reduced side-effect potential, several emerging drug candidates have advanced to human proof-of-concept in recent years. One such compound is a nonprostaglandin (non-PG) EP2-receptor-selective agonist (omidenepag isopropyl ester). Omidenepag (OMD; free acid form) is a novel non-PG that selectively binds to and activates the human EP2-prostglandin receptor (EP2R) with a high affinity (Ki = 3.6 nM) and which potently generates intracellular cAMP in living cells (EC50 = 3.9-8.3 nM). OMD significantly downregulated COL12A1 and COL13A1 mRNAs in human trabecular meshwork (TM) cells, a tissue involved in the pathogenesis of OHT. Omidenepag isopropyl (OMDI) potently and efficaciously lowered intraocular pressure (IOP) in ocular normotensive rabbits, dogs, and monkeys, and also in ocular hypertension (OHT) Cynomolgus monkeys, after a single topical ocular (t.o.) instillation at doses of 0.0001-0.01%. No reduction in IOP-lowering response to OMDI was observed after repeated t.o. dosing with OMDI in dogs and monkeys. Additive IOP reduction to OMDI was noted with brinzolamide, timolol, and brimonidine in rabbits and monkeys. OMDI 0.002% t.o. decreased IOP by stimulating the conventional (TM) and uveoscleral (UVSC) outflow of aqueous humor (AQH) in OHT monkeys. In a Phase-III clinical investigation, 0.002% OMDI (once daily t.o.) reduced IOP by 5-6 mmHg in OHT/primary open-angle glaucoma (POAG) patients (22-34 mmHg baseline IOPs) that was maintained over 12-months. In an additional month-long clinical study, 0.002% OMDI induced IOP-lowering equivalent to that of latanoprost (0.005%), a prostanoid FP-receptor agonist, thus OMDI was noninferior to latanoprost. Additive IOPreduction was also noted in OHT/OAG patients when OMDI (0.002%, once daily t.o.) and timolol (0.05%, twice daily t.o.) were administered. Patients with OHT/POAG who were low responders or nonresponders to latanoprost (0.005%, q.d.; t.o.) experienced significant IOP-lowering (additional approximately 3 mmHg) when they were switched over to OMDI 0.002% (q.d.; t.o.). No systemic or ocular adverse reactions (e.g. iris color changes/deepening of the upper eyelid sulcus/abnormal eyelash growth) were noted after a year-long, once-daily t.o. dosing with 0.002 % OMDI in OHT/POAG patients. However, OMDI caused transient conjunctival hyperemia. These characteristics of OMDI render it a suitable new medication for treating OHT and various types of glaucoma, especially where elevated IOP is implicated.

Synergic effects of EP2 and FP receptors co-activation on Blood-Retinal Barrier and Microglia

Macular edema (ME) is caused with disruption of the blood-retinal barrier (BRB) followed by fluid accumulation in the subretinal space. Main components of the outer and inner BRB are retinal pigment epithelial (RPE) cells and retinal microvascular endothelial cells, respectively. In addition, glial cells also participate in the functional regulation of the BRB as the member of 'neurovascular unit'. Under various stresses, cells in neurovascular units secrete inflammatory cytokines. Neuroinflammation induced by these cytokines can cause BRB dysfunction by degrading barrier-related proteins and contribute to the pathophysiology of ME. Prostaglandins (PGs) are crucial lipid mediators involved in neuroinflammation. Among PGs, a novel EP2 agonist, omidenepag (OMD) acts on not only the uveoscleral pathway but also the conventional pathway, unlike F prostanoid (FP) receptor agonists. Moreover, the combination use of the EP and the FP agonist is not recommended because of the risk of inflammation. In this study, we investigated effects of OMD and latanoprost acid (LTA), a FP agonist, on BRB and microglia in vitro and in vivo. To investigate the function of outer/inner BRB and microglia, in vitro, ARPE-19 cells, human retinal microvascular endothelial cells (HRMECs), and MG5 cells were used. Cell viability, inflammatory cytokines mRNA and protein levels, barrier morphology/function, and microglial activation were evaluated using proliferation assays, qRT-PCR, ELISA, immunocytochemistry, trans-epithelial electrical resistance, and permeability assay. Moreover, after vitreous injection into the mouse, outer BRB morphology, glial activation, and cytokine expression were assessed. Each OMD and LTA alone did not affect the viability or cytokines expression of the three types of cells. In ARPE-19 cells, the co-stimulation of OMD and LTA increased the mRNA and protein levels of inflammatory cytokines (IL-6, TNF-α, and VEGF-A) and decreased the barrier function and the junction-related protein (ZO-1 and β-catenin). By contrast in HRMECs, the co-stimulation affected significant differences in the mRNA levels of some cytokine (IL-6 and TNF-α) but enhanced the barrier function. In MG5 cells, the cytokines mRNA and size of Iba1-expressed cell were increased. A non-steroidal anti-inflammatory inhibited the barrier dysfunction and the junction-related protein downregulation in ARPE-19 cells and activation of MG5 cells. Also in vivo, the co-stimulation induced outer BRB disruption, cytokine increase, and retinal glial activation. Therefore, the co-stimulation of EP2 and FP induced the inflammatory cytokine-mediated outer BRB disruption, the enhanced inner BRB function, and the microglial activation. The BRB imbalance and the intrinsic prostaglandin production may be involved in OMD-related inflammation.

Therapeutic strategies for glaucoma and optic neuropathies

Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.

Synthesis and clinical application of new drugs approved by FDA in 2022

The pharmaceutical industry had a glorious year in 2022, with a total of 37 new drugs including 20 new chemical entities (NCEs) and 17 new biological entities (NBEs) approved by the Food and Drug Administration (FDA). These drugs are mainly concentrated in oncology, central nervous system, antiinfection, hematology, cardiomyopathy, dermatology, digestive system, ophthalmology, MRI enhancer and other therapeutic fields. Of the 37 drugs, 25 (68%) were approved through an expedited review pathway, and 19 (51%) were approved to treat rare diseases. These newly listed drugs have unique structures and new mechanisms of action, which can serve as lead compounds for designing new drugs with similar biological targets and enhancing therapeutic efficacy. This review aims to outline the clinical applications and synthetic methods of 19 NCEs newly approved by the FDA in 2022, but excludes contrast agent (Xenon Xe-129). We believe that an in-depth understanding of the synthetic methods of drug molecules will provide innovative and practical inspiration for the development of new, more effective, and practical synthetic techniques. According to the therapeutic areas of these 2022 FDA-approved drugs, we have classified these 19 NCEs into seven categories and will introduce them in the order of their approval for marketing.

Simultaneous Effects of a Selective EP2 Agonist, Omidenepag, and a Rho-Associated Coiled-Coil Containing Protein Kinase Inhibitor, Ripasudil, on Human Orbital Fibroblasts

Purpose: To assess the combined effects of omidenepag (OMD), a selective EP2 agonist, and ripasudil (Rip), an inhibitor of rho-associated coiled-coil containing protein kinases, on the human orbital adipose tissue, two-dimensional (2D) or three-dimensional (3D) cultures of human orbital fibroblasts (HOFs) were employed. Methods: Cellular metabolic functions (2D), physical (3D), lipid staining (3D), and quantitative polymerase chain reaction for adipogenesis-related genes, PPARγ and AP2, and extracellular matrix (ECM) molecules, including collagen (COL)1, 4, and 6, and fibronectin (FN) (3D) were evaluated in the presence of OMD (100 nM) and/or Rip (10 μM). Results: Real-time metabolic analyses revealed that the adipogenic differentiation (DIF+) with OMD significantly shifted an energetic state toward energetic, whereas DIF+ with Rip significantly shifted that toward quiescent. In the case of both drugs upon DIF+, the metabolic effect of OMD was predominant. DIF+ induced enlargement and stiffed 3D spheroid with increased lipid staining and mRNA expression of adipogenesis-related genes, COL4 and COL6, and decreased the expression of COL1. In the presence of OMD and/or Rip to DIF+, (1) the sizes were further increased by Rip and the stiffness was significantly decreased by OMD or Rip and (2) COL4 or AP2 expression was substantially increased by OMD or Rip, respectively. Conclusion: The results presented herein indicate that the metabolic effects of OMD and Rip exerted opposing effects and the effects of OMD toward Ap2 and ECM expressions were distinct from those of Rip, but the effects of OMD toward the physical aspects and adipogenesis of the 3D cultured HOFs were similar to the effects of Rip.

Cystoid macular edema associated with omidenepag isopropyl in a phakic eye with an implantable collamer lens: a case report

BACKGROUND

Cystoid macular edema is a known complication of omidenepag isopropyl usage. Omidenepag isopropyl is a selective prostanoid EP2 receptor agonist, and its association with macular edema has mainly been identified in pseudophakic eyes. Herein, we report a case of cystoid macular edema caused by omidenepag isopropyl use in a phakic eye with an implantable collamer lens.

CASE PRESENTATION

A 38-year-old woman was diagnosed with left eye glaucoma and prescribed omidenepag isopropyl. She had undergone bilateral implantation of implantable collamer lenses approximately 12 years prior to the glaucoma diagnosis. After 9 months of using omidenepag isopropyl, she presented with blurred vision in the left eye; swept source optical coherence tomography revealed cystoid macular edema in this eye. Omidenepag isopropyl usage was discontinued, and bromfenac sodium hydrate was administered twice daily instead. After 2 months, the patient's visual discomfort was completely ameliorated. Additionally, an optical coherence tomography examination confirmed that the macula had normalized.

CONCLUSIONS

We report a case of cystoid macular edema development after omidenepag isopropyl use in a patient with glaucoma who had undergone bilateral implantable collamer lens implantation. This case shows that the possibility of cystoid macular edema occurrence should be considered when omidenepag isopropyl is used, even in phakic eyes, after the insertion of implantable collamer lenses.

Prostanoid FP and EP2 Receptor Agonists Induce Epithelial and Subepithelial Fibrogenetic Changes in Human Conjunctival Fibroblasts in Different Manners

Purpose: To examine the effects of prostanoid FP and EP2 receptor agonists, PGF2α and Omidenepag (OMD), respectively, on the transforming growth factor beta (TGF-β2) induced conjunctival fibrogenesis. Methods: Two-dimension (2D) and three-dimension (3D) cultures of these fibroblasts were subjected to following analyses: (1) planar proliferation evaluated by transendothelial electron resistance (TEER) measurements, (2) real-time metabolic analyses, (3) subepithelial proliferation evaluated by 3D spheroid' size and stiffness measurements, and (4) the mRNA expression of extracellular matrix (ECM) molecules and their modulators. Results: TGF-β2 induced increase in the planar proliferation was significantly decreased or enhanced by PGF2α or OMD, respectively. The proportion of oxygen consumption required to drive ATP synthesis compared with that driving proton leakage was increased by PGF2α and OMD independently with TGF-β2. In contrast, maximal mitochondrial respiration was decreased by PGF2α and OMD, and the OMD-induced effect was further enhanced by the presence of TGF-β2. In addition, the TGF-β2 dependent increase in the glycolytic capacity was cancelled by PGF2α and/or OMD. Alternatively, subepithelial proliferation, as evidenced by the stiffness of the 3D spheroids, was substantially increased by both PGF2α and OMD, and these were differently modulated by TGF-β2. The expression of several related factors as above fluctuated among the conditions for both 2D and 3D and TGF-β2 untreated or treated cultures. Conclusion: The present findings indicate that the prostanoid FP or the EP2 receptor agonist may solely and differently induce the planar and subepithelial proliferation of HconF cells and these were also modulated by TGF-β2.

Identifying new drugs and targets to treat rapidly elevated intraocular pressure for angle closure and secondary glaucomas to curb visual impairment and prevent blindness

A multitude of pharmacological compounds have been shown to lower and control intraocular pressure (IOP) in numerous species of animals and human subjects after topical ocular dosing or via other routes of administration. Most researchers have been interested in finding drug candidates that exhibit a relatively long duration of action from a chronic therapeutic use perspective, for example to treat ocular hypertension (OHT), primary open-angle glaucoma and even normotensive glaucoma. However, it is equally important to seek and characterize treatment modalities which offer a rapid onset of action to help provide fast relief from quickly rising IOP that occurs in certain eye diseases. These include acute angle-closure glaucoma, primary angle-closure glaucoma, uveitic and inflammatory glaucoma, medication-induced OHT, and other secondary glaucomas induced by eye injury or infection which can cause partial or complete loss of eyesight. Such fast-acting agents can delay or prevent the need for ocular surgery which is often used to lower the dangerously raised IOP. This research survey was therefore directed at identifying agents from the literature that demonstrated ocular hypotensive activity, normalizing and unifying the data, determining their onset of action and rank ordering them on the basis of rapidity of action starting within 30-60 min and lasting up to at least 3-4 h post topical ocular dosing in different animal species. This research revealed a few health authority-approved drugs and some investigational compounds that appear to meet the necessary criteria of fast onset of action coupled with significant efficacy to reduce elevated IOP (by ≥ 20%, preferably by >30%). However, translation of the novel animal-based findings to the human conditions remains to be demonstrated but represent viable targets, especially EP2-receptor agonists (e.g. omidenepag isopropyl; AL-6598; butaprost), mixed activity serotonin/dopamine receptor agonists (e.g. cabergoline), rho kinase inhibitors (e.g. AMA0076, Y39983), CACNA2D1-gene product inhibitors (e.g. pregabalin), melatonin receptor agonists, and certain K+-channel openers (e.g. nicorandil, pinacidil). Other drug candidates and targets were also identified and will be discussed.

Recently Approved Drugs for Lowering and Controlling Intraocular Pressure to Reduce Vision Loss in Ocular Hypertensive and Glaucoma Patients

Serious vision loss occurs in patients affected by chronically raised intraocular pressure (IOP), a characteristic of many forms of glaucoma where damage to the optic nerve components causes progressive degeneration of retinal and brain neurons involved in visual perception. While many risk factors abound and have been validated for this glaucomatous optic neuropathy (GON), the major one is ocular hypertension (OHT), which results from the accumulation of excess aqueous humor (AQH) fluid in the anterior chamber of the eye. Millions around the world suffer from this asymptomatic and progressive degenerative eye disease. Since clinical evidence has revealed a strong correlation between the reduction in elevated IOP/OHT and GON progression, many drugs, devices, and surgical techniques have been developed to lower and control IOP. The constant quest for new pharmaceuticals and other modalities with superior therapeutic indices has recently yielded health authority-approved novel drugs with unique pharmacological signatures and mechanism(s) of action and AQH drainage microdevices for effectively and durably treating OHT. A unique nitric oxide-donating conjugate of latanoprost, an FP-receptor prostaglandin (PG; latanoprostene bunod), new rho kinase inhibitors (ripasudil; netarsudil), a novel non-PG EP2-receptor-selective agonist (omidenepag isopropyl), and a form of FP-receptor PG in a slow-release intracameral implant (Durysta) represent the additions to the pharmaceutical toolchest to mitigate the ravages of OHT. Despite these advances, early diagnosis of OHT and glaucoma still lags behind and would benefit from further concerted effort and attention.

Influence of 0.002% Omidenepag Isopropyl on Intraocular Pressure and the Cornea in Normal Tension Glaucoma

PRCIS

Although Omidenepag isopropyl drops elicited stable intraocular pressure reductions in NTG patients, transient changes in refraction and corneal endothelial cells, significant increase of central corneal thickness, and corneal erosion should be considered.

PURPOSE

To analyze the efficacy and safety of 0.002% omidenepag Isopropyl (OMDI) eye drops in patients with normal tension glaucoma (NTG).

METHODS

Medical records for 62 eyes treated with OMDI for ≥6 months were analyzed. Intraocular pressure (IOP), refraction, keratometry, central corneal thickness (CCT), endothelial cell count, coefficient of variation of endothelial cell area (CV), corneal erosion, and central retinal thickness were compared at baseline and 1, 3, and 6 months.

RESULTS

IOP significantly decreased from 13.4±3.8 to 11.9±3.0, 11.7±2.9, and 12.2±3.3 mm Hg at each follow-up ( P <0.001). Endothelial cell count did not change, but CV transiently increased from 12.6 to 17.0 at 1 month, CCT increased from 531.5 to 538.4 μm, myopia changed from -1.5 to -1.9 D, and keratometry changed from 44.5 to 44.7 D. CV, myopia, and keratometry recovered to baseline at 6 months; however, CCT remained high. Significant corneal erosion was observed at 6 months. Central retinal thickness changes were not observed. There were improvements in prostaglandin-associated skin pigmentation (86.7%), eyelash elongation (40.0%), and deepening of the upper eyelid sulcus and ptosis (~30%) at 3 months after exchange to OMDI. Adverse reactions were corneal erosion (27.4%), corneal thickening (21.0%), conjunctival hyperemia (11.3%), photophobia (5.7%), blurred vision (5.7%), and anterior chamber cells (4.8%).

CONCLUSIONS

OMDI eye drops elicited significant and stable IOP reductions after 6 months in NTG patients with low IOP. However, transient myopic and corneal endothelial cell changes, development of corneal thickening, and corneal erosion should be considered when using OMDI.

FP and EP2 prostanoid receptor agonist drugs and aqueous humor outflow devices for treating ocular hypertension and glaucoma

Prostaglandin (PG) receptors represent important druggable targets due to the many diverse actions of PGs in the body. From an ocular perspective, the discovery, development, and health agency approvals of prostaglandin F (FP) receptor agonists (FPAs) have revolutionized the medical treatment of ocular hypertension (OHT) and glaucoma. FPAs, such as latanoprost, travoprost, bimatoprost, and tafluprost, powerfully lower and control intraocular pressure (IOP), and became first-line therapeutics to treat this leading cause of blindness in the late 1990s to early 2000s. More recently, a latanoprost-nitric oxide (NO) donor conjugate, latanoprostene bunod, and a novel FP/EP3 receptor dual agonist, sepetaprost (ONO-9054 or DE-126), have also demonstrated robust IOP-reducing activity. Moreover, a selective non-PG prostanoid EP2 receptor agonist, omidenepag isopropyl (OMDI), was discovered, characterized, and has been approved in the United States, Japan and several other Asian countries for treating OHT/glaucoma. FPAs primarily enhance uveoscleral (UVSC) outflow of aqueous humor (AQH) to reduce IOP, but cause darkening of the iris and periorbital skin, uneven thickening and elongation of eyelashes, and deepening of the upper eyelid sulcus during chronic treatment. In contrast, OMDI lowers and controls IOP by activation of both the UVSC and trabecular meshwork outflow pathways, and it has a lower propensity to induce the aforementioned FPA-induced ocular side effects. Another means to address OHT is to physically promote the drainage of the AQH from the anterior chamber of the eye of patients with OHT/glaucoma. This has successfully been achieved by the recent approval and introduction of miniature devices into the anterior chamber by minimally invasive glaucoma surgeries. This review covers the three major aspects mentioned above to highlight the etiology of OHT/glaucoma, and the pharmacotherapeutics and devices that can be used to combat this blinding ocular disease.

The roles of COX-2 in protozoan infection

Protozoan diseases cause great harm in animal husbandry and require human-provided medical treatment. Protozoan infection can induce changes in cyclooxygenase-2 (COX-2) expression. The role played by COX-2 in the response to protozoan infection is complex. COX-2 induces and regulates inflammation by promoting the synthesis of different prostaglandins (PGs), which exhibit a variety of biological activities and participate in pathophysiological processes in the body in a variety of ways. This review explains the roles played by COX-2 in protozoan infection and analyzes the effects of COX-2-related drugs in protozoan diseases.

Downregulation of COL12A1 and COL13A1 by a selective EP2 receptor agonist, omidenepag, in human trabecular meshwork cells

Omidenepag isopropyl (OMDI) is an intraocular pressure (IOP)-lowering drug used to treat glaucoma. The active form of OMDI, omidenepag (OMD), lowers elevated IOP, the main risk factor for glaucoma, by increasing the aqueous humor outflow; however, a detailed understanding of this mechanism is lacking. To clarify the IOP-lowering mechanism of OMDI, the effects of OMD on the mRNA expression of the extracellular matrix, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs) were evaluated in human trabecular meshwork cells. Under 2D culture conditions, the mRNA expression of FN1, COL1A1, COL1A2, COL12A1, and COL13A1 decreased in a concentration-dependent manner after 6 or 24 h treatment with 10 nM, 100 nM, and 1 μM OMD, while that of COL18A1 decreased after 6 h treatment with 1 μM OMD. Significant changes in expression were observed for many MMP and TIMP genes. Under 3D culture conditions, the extracellular matrix-related genes COL12A1 and COL13A1 were downregulated by OMD treatment at all three concentrations. Under both 2D and 3D culture conditions, COL12A1 and COL13A1 were downregulated following OMD treatment. Reduction in the extracellular matrix contributes to the decrease in outflow resistance, suggesting that the downregulation of the two related genes may be one of the factors influencing the IOP-lowering effect of OMDI. Our findings provide insights for the use of OMDI in clinical practice.

Protocol for laser-induced chronic ocular hypertension and intracameral injection in nonhuman primates

Laser-induced hypertension in nonhuman primates is used to mimic human glaucoma, the leading cause of irreversible blindness. In this protocol, we detail steps for laser-induced ocular hypertension in nonhuman primates by laser photocoagulation of the trabecular meshwork and subsequent intracameral injection. We further describe recording and evaluation of intraocular pressure changes and peripapillary retinal nerve fiber layer thickness. This protocol can assist researchers improve the success rate and repeatability of the procedure and reduce the number of nonhuman primates needed.

For complete details on the use and execution of this protocol, please refer to Sun et al. (2022).

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Detailed description for general and ophthalmological examination before experiment

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Protocol to generate laser-induced chronic ocular hypertension in rhesus monkeys

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Laser photocoagulation of the trabecular meshwork followed by intracameral injection

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Approach is highly reproducible and offers a tool to test potential treatment strategies

Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

Emerging drugs for the treatment of glaucoma: a review of phase II & III trials

INTRODUCTION

Glaucoma is a progressive optic neuropathy and the leading cause of irreversible vision loss. By 2040, the number of individuals with glaucoma is expected to nearly double. The only known modifiable risk factor for glaucoma is intraocular pressure. Topical medications are often used as first-line therapies. Although there are numerous available treatments, there continues to be a need for the development of new medical therapies due to variable response, intolerable side-effect profiles in some patients, and elevated intraocular pressure refractory to other treatments.

AREAS COVERED

This review will cover glaucoma medications currently undergoing phase II and III of drug development.

EXPERT OPINION

There are numerous drugs currently in development that have demonstrated significant and clinically relevant reduction of intraocular pressure. Differentiating factors include improved tolerability, novel mechanisms of action, multiple mechanisms of action, or superior IOP reduction. However, the availability of generic prostaglandin analogs may limit adoption of these novel compounds as first-line agents, except for certain subgroups of glaucoma patients. Use as adjuvant or second-line therapy appears more likely for the majority of glaucoma patients.

The Piezo1 ion channel in glaucoma: a new perspective on mechanical stress

Glaucomatous optic nerve damage caused by pathological intraocular pressure elevation is irreversible, and its course is often difficult to control. This group of eye diseases is closely related to biomechanics, and the correlation between glaucoma pathogenesis and mechanical stimulation has been studied in recent decades. The nonselective cation channel Piezo1, the most important known mechanical stress sensor, is a transmembrane protein widely expressed in various cell types. Piezo1 has been detected throughout the eye, and the close relationship between Piezo1 and glaucoma is being confirmed. Pathological changes in glaucoma occur in both the anterior and posterior segments of the eye, and it is of great interest for researchers to determine whether Piezo1 plays a role in these changes and how it functions. The elucidation of the mechanisms of Piezo1 action in nonocular tissues and the reported roles of similar mechanically activated ion channels in glaucoma will provide an appropriate basis for further investigation. From a new perspective, this review provides a detailed description of the current progress in elucidating the role of Piezo1 in glaucoma, including relevant questions and assumptions, the remaining challenging research directions and mechanism-related therapeutic potential.

Degeneration of retina-brain components and connections in glaucoma: Disease causation and treatment options for eyesight preservation

Eyesight is the most important of our sensory systems for optimal daily activities and overall survival. Patients who experience visual impairment due to elevated intraocular pressure (IOP) are often those afflicted with primary open-angle glaucoma (POAG) which slowly robs them of their vision unless treatment is administered soon after diagnosis. The hallmark features of POAG and other forms of glaucoma are damaged optic nerve, retinal ganglion cell (RGC) loss and atrophied RGC axons connecting to various brain regions associated with receipt of visual input from the eyes and eventual decoding and perception of images in the visual cortex. Even though increased IOP is the major risk factor for POAG, the disease is caused by many injurious chemicals and events that progress slowly within all components of the eye-brain visual axis. Lowering of IOP mitigates the damage to some extent with existing drugs, surgical and device implantation therapeutic interventions. However, since multifactorial degenerative processes occur during aging and with glaucomatous optic neuropathy, different forms of neuroprotective, nutraceutical and electroceutical regenerative and revitalizing agents and processes are being considered to combat these eye-brain disorders. These aspects form the basis of this short review article.

One-Year Efficacy and Safety of Omidenepag Isopropyl in Patients with Normal-Tension Glaucoma

Purpose: To retrospectively evaluate the 1-year efficacy and safety of single-agent of omidenepag isopropyl in patients with normal-tension glaucoma (NTG). Methods: One hundred patients (100 eyes) newly administered omidenepag isopropyl were enrolled. Intraocular pressure (IOP) was compared at baseline and 3, 6, 9, and 12 months after administration. The mean deviation values at baseline and 12 months measured using the Humphrey visual field test (30-2 Swedish Interactive Threshold Algorithm standard) were compared. Adverse reactions and dropouts were observed. Results: IOP significantly decreased from 15.5 ± 2.7 mmHg at baseline to 13.3 ± 2.5 mmHg after 3 months, 13.7 ± 2.3 mmHg after 6 months, 13.9 ± 2.4 mmHg after 9 months, and 13.7 ± 2.3 mmHg after 12 months (P < 0.0001). There was no significant difference in the mean deviation values at baseline (-3.66 ± 3.49 dB) and after 12 months (-3.41 ± 3.80 dB). Adverse reactions occurred in 9 patients (9.0%): conjunctival hyperemia (n = 6), eye pain (n = 1), iritis (n = 1), and blepharitis (n = 1). Twenty-one patients (21.0%) discontinued administration because of changes in medication (n = 7), interruption of visits (n = 5), adverse reactions (n = 4), and others. Conclusions: After administering omidenepag isopropyl, the IOP in patients with NTG decreased within 1 year, visual fields were maintained, and safety was satisfactory. Omidenepag isopropyl can be used as the first-line medication for patients with NTG.

Periocular Adverse Reactions to Omidenepag Isopropyl

PURPOSE

To investigate the periocular adverse reactions to omidenepag isopropyl (OMDI).

DESIGN

Nonrandomized comparative clinical study.

METHODS

We enrolled 100 patients (100 eyes) with primary open-angle glaucoma or ocular hypertension who received initial treatment with OMDI or tafluprost in only 1 eye for ≥6 months. Photographs of the eyelids were taken on the day of the participants' visit after ≥6 months of prescription. Subsequently, 3 ophthalmologists individually determined the occurrence of eyelid pigmentation, eyelash growth, and deepening of the upper eyelid sulcus (DUES). Additionally, a questionnaire on the subjective symptoms was administered. Multivariate analysis of baseline data was performed to investigate the factors involved in adverse reactions.

RESULTS

The mean duration of drug administration was 10.2 ± 3.8 and 10.8 ± 4.1 months in the OMDI and tafluprost groups, respectively. The frequencies of eyelid pigmentation, eyelash growth, and DUES were 0.0%, 0.0%, and 2.0%, respectively, in the OMDI group, whereas the corresponding values in the tafluprost group were 4.0%, 32.0%, and 12.0%. The only significant difference was that the OMDI group showed fewer patients with eyelash growth than in the tafluprost group (P < .0001). In the questionnaire, the subjective symptoms of eyelid pigmentation, eyelash growth, and DUES were 8.0%, 2.0%, and 4.0%, respectively, in the OMDI group, whereas the corresponding values in the tafluprost group were 12.0%, 40.0%, and 4.0%, respectively. Multivariate analysis revealed a correlation between the type of drug administered and these adverse reactions (R = 0.38, P = .005).

CONCLUSIONS

The frequencies of periocular adverse reactions to OMDI, ranging from 0% to 2.0%, were lower than those to tafluprost.

Efficacy and Patient Tolerability of Omidenepag Isopropyl in the Treatment of Glaucoma and Ocular Hypertension

Current therapeutic approaches for glaucoma aim to reduce intraocular pressure (IOP), which is the only available and reliable strategy proven to control the risk of disease development and progression. Omidenepag isopropyl (OMDI) is a novel topical ocular hypotensive agent that was launched onto the market for the treatment of glaucoma and ocular hypertension (OHT). After topical instillation and during corneal penetration, OMDI is converted into the active metabolite omidenepag (OMD), which behaves as a non-prostaglandin, selective E-prostanoid subtype 2 (EP2) receptor agonist. The topical administration of 0.002% OMDI once-daily (QD) possesses a 20–35% IOP-lowering effect, comparable to that of prostaglandin analogs targeting F-prostanoid (FP) receptor QD, which are the current first-line for pharmaceutical reduction of IOP. However, the mechanism of action and adverse events (AEs) of OMDI are different from those of FP receptor agonists. OMDI reduces IOP by enhancing both conventional trabecular and uveoscleral outflow facilities without complications of prostaglandin-associated periorbitopathy (PAP) seen with FP receptor agonists. Moreover, OMDI was also effective and well-tolerated in non-/poor responders to latanoprost and showed a stable IOP-lowering effect for one year, and its concomitant use with timolol enhanced the IOP-lowering effect. OMDI demonstrated acceptable safety and tolerability with good adherence and can be used in almost every patient. However, OMDI has some AEs such as conjunctival hyperemia, corneal thickening, macular edema/cystoid macular edema and ocular inflammation. Moreover, OMDI is contraindicated in patients who are allergic to the product, in aphakic or pseudophakic eyes, and in combination with tafluprost eye drops. If used appropriately in the right patients, OMDI could be an effective treatment option for glaucoma and OHT as a first-line alternative to FP agonists. Here, we summarize the results of clinical studies of OMDI and discuss its efficacy and patient tolerability in glaucoma and OHT in this review.

Comparison of the Drug-Induced Efficacies between Omidenepag Isopropyl, an EP2 Agonist and PGF2α toward TGF-β2-Modulated Human Trabecular Meshwork (HTM) Cells

To compare the drug-induced efficacies between omidenepag (OMD), an EP2 agonist, and prostaglandin F2α (PGF2α) on glaucomatous trabecular meshwork (TM) cells, two- and three-dimensional (2D and 3D) cultures of TGF-β2-modulated human trabecular meshwork (HTM) cells were used. The following analyses were performed: (1) transendothelial electrical resistance (TEER) and FITC-dextran permeability measurements (2D), (2) the size and stiffness of the 3D spheroids, and (3) the expression (both 2D and 3D) by several extracellular matrix (ECM) molecules including collagen (COL) 1, 4 and 6, and fibronectin (FN), and α smooth muscle actin (αSMA), tight junction (TJ)-related molecules, claudin11 (Cldn11) and ZO1, the tissue inhibitor of metalloproteinase (TIMP) 1–4, matrix metalloproteinase (MMP) 2, 9 and 14, connective tissue growth factor (CTGF), and several endoplasmic reticulum (ER) stress-related factors. TGF-β2 significantly increased the TEER values and decreased FITC-dextran permeability, respectively, in the 2D HTM monolayers, and induced the formation of downsized and stiffer 3D HTM spheroids. TGF-β2-induced changes in TEER levels and FITC-dextran permeability were remarkably inhibited by PGF2α. PGF2α induced increases in the sizes and stiffness of the TGF-β2-treated 3D spheroids, but OMD enhanced only spheroid size. Upon exposure to TGF-β2, the expression of most of the molecules that were evaluated were significantly up-regulated, except some of ER stress-related factors were down-regulated. TJ-related molecules or ER stress-related factors were significantly up-regulated (2D) or down-regulated (3D), and down-regulated (2D) by PGF2α and OMD, while both drugs altered the expression of some of the other genes in the 3D spheroids in a different manner. The findings presented herein suggest that PGF2α and OMD differently modulate the permeability of the TGFβ2-modulated 2D monolayers and the physical properties of the 3D HTM spheroids.

Interim Results of Post-Marketing Observational Study of Omidenepag Isopropyl for Glaucoma and Ocular Hypertension in Japan

INTRODUCTION

This post-marketing observational interim analysis evaluated the 12-month effectiveness and safety of omidenepag isopropyl (OMDI) ophthalmic solution in daily clinical settings.

METHODS

This was a multicenter, large-scale, non-interventional, prospective, observational study conducted in Japan. The target enrollment was 3900 patients, and the overall observation period was 12 months. Patients with glaucoma and ocular hypertension (OH) with no previous history of OMDI use were enrolled. The key endpoints were change in intraocular pressure (IOP) from baseline and the incidence of adverse reactions (ADRs).

RESULTS

A total of 1862 patients were evaluated in this 12-month interim analysis. Most patients were diagnosed with normal-tension glaucoma (NTG, 62.0%). The treatment patterns with OMDI were naïve monotherapy (48.4%), switching monotherapy (18.4%), and concomitant therapy (31.1%). The overall incidence of ADRs was 24.3%, which was similar between the monotherapy and concomitant therapy groups. Common ADRs were conjunctival hyperemia, refractive disorder, and myopia. Macular edema was observed in four patients. No ADRs categorized as prostaglandin-associated periorbitopathy were observed. There was a significant reduction in mean IOP at 12 months, with a change of - 1.9 ± 2.9 mmHg from baseline (reduction - 10.4 ± 16.5%). The mean IOP change from baseline was - 2.7 ± 2.6 mmHg in the naïve monotherapy group, - 1.1 ± 2.6 mmHg in the switching monotherapy group, and - 1.6 ± 3.1 mmHg in the concomitant therapy group (all P < 0.05). The mean IOP decreased by - 2.5 ± 3.2 mmHg, - 1.5 ± 2.4 mmHg, and - 2.3 ± 4.5 mmHg in the primary open-angle glaucoma (POAG), NTG, and OH groups, respectively. The treatment persistence with OMDI was 82.4%.

CONCLUSION

This study demonstrated the safety and efficacy of OMDI for glaucoma and OH as monotherapy and concomitant therapy in daily clinical settings. In this interim analysis, OMDI showed a favorable benefit-risk profile, and can be first-line therapy for glaucoma.

Medical therapy for glaucoma: A review

A number of pharmacological targets are exploited to modify the parameters in the Goldmann equation and reduce the intraocular pressure (IOP). This strategy constitutes the foundation for the medical management of glaucoma, the evolution of which, until only recently, has been in relative stagnation. A burst of innovation has produced new ocular hypotensive drugs and long-acting delivery methods, including intracameral delivery, which are expanding the clinician's medical armamentarium. A number of IOP-independent neuroprotection strategies have shown strong potential in animal models of glaucoma, but translational attempts have been surprisingly limited. However, while pharmacological options are expanding, the traditional role of topical medical therapy is being challenged by selective laser trabeculoplasty, micro-invasive glaucoma surgery, and sustained delivery methods. A scientifically rigorous assessment of new treatments will be critical to empower clinicians with evidence-based information to optimise vision preservation and quality of life outcomes for their patients.

Effect of Prostaglandin E2 Agonist Omidenepag on the Expression of Matrix Metalloproteinase in Trabecular Meshwork Cells

Purpose

To investigate the effects of prostaglandin E2 agonist omidenepag (OMD) on the expression of matrix metalloproteinase (MMP) in human trabecular meshwork (TM) cells.

Methods

Primarily cultured human TM cells were exposed to 0, 1, 10, or 40 μmol/L OMD for 3 days. The permeability through the TM cell monolayer was assessed using carboxyfluorescein. Expressions of messenger ribonucleic acid and protein levels of MMP-1, MMP-3, and MMP-9 were measured by reverse transcription polymerase chain reaction and Western blotting, respectively. Also, the permeability, expression of messenger ribonucleic acid, and protein levels of MMPs were measured after exposure to 1 μmol/L latanoprost free acid (LAT).

Results

OMD and LAT did not affect the cellular survival (all p > 0.05). Each concentration of OMD and LAT did not affect the permeability of carboxyfluorescein significantly (all p > 0.05). LAT increased the level of MMP-1 protein but did not increase the levels of MMP-3 and MMP-9 proteins. Each concentration of OMD did not affect the levels of MMP-1, MMP-3, and MMP-9 proteins (all p > 0.05)

Conclusions

In TM cells, prostaglandin E2 agonist OMD did not increase the permeability through the TM cell monolayer, and the protein levels of MMPs. These suggest that the direct effect on the trabecular outflow by OMD may be limited.

Topical Medication Therapy for Glaucoma and Ocular Hypertension

Glaucoma is one of the most common causes of blindness, thus seriously affecting people’s health and quality of life. The topical medical therapy is as the first line treatment in the management of glaucoma since it is inexpensive, convenient, effective, and safe. This review summarizes and compares extensive clinical trials on the topical medications for the treatment of glaucoma, including topical monotherapy agents, topical fixed-combination agents, topical non-fixed combination agents, and their composition, mechanism of action, efficacy, and adverse effects, which will provide reference for optimal choice of clinical medication. Fixed-combination therapeutics offer greater efficacy, reliable security, clinical compliance, and tolerance than non-fixed combination agents and monotherapy agents, which will become a prefer option for the treatment of glaucoma. Meanwhile, we also discuss new trends in the field of new fixed combinations of medications, which may better control IOP and treat glaucoma.

The EP2 agonist, omidenepag, alters the physical stiffness of 3D spheroids prepared from human corneal stroma fibroblasts differently depending on the osmotic pressure

The objective of the current study was to examine the drug-induced effects of the EP2 agonist, omidenapag (OMD), on human corneal stroma, two- and three-dimensional (2D and 3D) cultures of human corneal stroma fibroblasts (HCSFs). The drug-induced effects on 2D monolayers and 3D spheroids were characterized by examining the ultrastructures by scanning electron microscope (SEM), transendothelial electrical resistance (TEER) measurements, and fluorescein isothiocyanate (FITC)-dextran permeability. The physical properties of 3D spheroids with respect to size and stiffness were also examined. In addition, the gene expressions of extracellular matrix (ECM) molecules, including collagen (COL) 1, 4, and 6, and fibronectin (FN), a tissue inhibitor of metalloproteinase (TIMP) 1-4, matrix metalloproteinase (MMP) 2, 9, and 14, aquaporin1 (AQP1), and several endoplasmic reticulum (ER) stress-related factors were evaluated. In the 2D HCSFs, OMD induced (1) a significant increase in ECM deposits, as evidenced by SEM, the mRNA expression of COL4 and FN, and (2) a decrease in TEER values and a concentration-dependent increase in FITC-dextran permeability. In the case of 3D spheroids, OMD had no effect on size but a substantial increase in stiffness was observed. Furthermore, such OMD-induced effects on stiffness were dramatically modulated by the osmotic pressure of the system. In contrast to the above 2D cultures, among the ECM molecules and the modulators of 3D spheroids, namely, TIMPS and MMPs, the down-regulation of COL1, TIMP1 and 2 and the up-regulation of MMP9 were observed. Interestingly, such diversity in terms of OMD-induced gene expressions between 2D and 3D cultures was also recognized in AQP1 (2D; no significant change, 3D; significant up-regulation) and ER stress-related genes. The findings presented herein suggest that the EP2 agonist, OMD, alters the physical stiffness of 3D spheroids obtained from human corneal stroma fibroblasts and this alteration is dependent on the osmotic pressures. 2D and 3D cell cultures may be useful for evaluating the drug induced effects of OMD toward human corneal stroma.

Prostaglandin F2 and EP2 Agonists Exert Different Effects on 3D 3T3-L1 Spheroids during Their Culture Phase

To elucidate the effects of switching a PGF2α agonist, bimatoprost acid (BIM-A), to an EP2 agonist (Omidenepag—OMD; butaprost—Buta) or reversing the switching on adipose tissue, two-dimensional (2D) and three-dimensional (3D) cultures of 3T3-L1 cells were analyzed by lipid staining and according to the mRNA expression of adipogenesis-related genes (Pparγ, Ap2, and Leptin), components of the extracellular matrix (ECM; collagen1 (Col1), Col4, Col6, and fibronectin (Fn)), and the sizes and stiffness of the 3D spheroids. Switching from BIM-A to EP2 agonists caused (1) suppression of lipid staining and downregulation of most adipogenesis-related genes, (2) smaller and stiffer 3D spheroids, and (3) upregulation of Col1 and Fn, downregulation of Col4 (2D), or up-regulation of all ECM genes (3D, BIM-A to OMD), as well as downregulation of Col6 (3D, BIM-A to Buta). In contrast, reversing the switching resulted in (1) an enhancement in lipid staining (2D) and a significant upregulation of adipogenesis-related genes (2D, 3D Buta to BIM-A), (2) larger and slightly stiffer 3D spheroids, and (3) upregulation of Col1 and Fn (2D). These collective findings indicate that the switching orders of BIM-A and EP2 agonists have a significant effect on lipid metabolism, ECM expression, and the physical stiffness of 3T3-L1 cells.

Prostaglandin-associated periorbitopathy syndrome (PAPS): Addressing an unmet clinical need

BACKGROUND

Topical prostaglandin analogs (PGAs) are widely approved and preferred first-line options for glaucoma and elevated intraocular pressure (IOP). However, prostaglandin-associated periorbitopathy syndrome (PAPS) is now a well-recognized clinical and cosmetic concern for patients receiving PGAs, especially during long-term and unilateral therapy. PGA-associated periocular changes occur in a substantial proportion of patients, with older patients (>60 years) at greater risk of clinical presentation. PAPS may hinder long-term management of glaucoma, including treatment adherence, ophthalmic surgery outcomes, and reliable IOP measurements.

RECOMMENDATION

New therapeutic approaches may address this unmet clinical need. Omidenepag isopropyl (OMDI) is a novel, non-prostaglandin, selective EP₂ receptor agonist in ongoing development, which provides a unique pharmacological mechanism of action. OMDI appears to provide IOP reductions comparable to PGAs, but without PAPS-related undesirable effects. OMDI may offer a suitable long-term option for patients who demonstrate decreased efficacy, or failure, of PGAs, plus patients with significant PAPS, while fulfilling international guidelines.

Cystoid Macular Edema Associated with Omidenepag Isopropyl in Phakic Eyes after Laser Iridotomy: A Case Report

Decreased vision and cystoid macular edema (CME) developed in phakic eyes of a patient who underwent laser iridotomy after changing the glaucoma eye drops from carteolol 2% long-acting ophthalmic solution to omidenepag isopropyl 0.002%. CME completely disappeared at approximately 2 months after discontinuation of omidenepag isopropyl in conjunction with the use of bromfenac sodium 0.1%.

Reactivities of a Prostanoid EP2 Agonist, Omidenepag, Are Useful for Distinguishing between 3D Spheroids of Human Orbital Fibroblasts without or with Graves' Orbitopathy

Background. To obtain new insights into the activation of the thyroid-stimulating hormone (TSH) and insulin-like growth factor 1 (IGF-1) receptors in human orbital fibroblasts (n-HOFs), the effects of the prostanoid EP2 agonist, omidenepag (OMD), and a rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor, ripasudil (Rip) were evaluated using three-dimension (3D) n-HOFs spheroids in the absence and presence of the recombinant human TSH receptor antibodies, M22 and IGF-1. Methods. The effects of 100 nM OMD or 10 μM Rip on the physical properties, size, stiffness, and mRNA expression of several extracellular matrix (ECM) molecules, their regulator, inflammatory cytokines, and endoplasmic reticulum (ER) stress-related factors were examined and compared among 3D spheroids of n-HOFs, M22-/IGF-1-activated n-HOFs and GO-related human orbital fibroblasts (GHOFs). Results. The physical properties and mRNA expressions of several genes of the 3D n-HOFs spheroids were significantly and diversely modulated by the presence of OMD or Rip. The OMD-induced effects on M22-/IGF-1-activated n-HOFs were similar to the effects caused by GHOHs, but quite different from those of n-HOFs. Conclusions. The findings presented herein indicate that the changes induced by OMD may be useful in distinguishing between n-HOFs and GHOFs.

Therapeutic Drugs and Devices for Tackling Ocular Hypertension and Glaucoma, and Need for Neuroprotection and Cytoprotective Therapies

Damage to the optic nerve and the death of associated retinal ganglion cells (RGCs) by elevated intraocular pressure (IOP), also known as glaucoma, is responsible for visual impairment and blindness in millions of people worldwide. The ocular hypertension (OHT) and the deleterious mechanical forces it exerts at the back of the eye, at the level of the optic nerve head/optic disc and lamina cribosa, is the only modifiable risk factor associated with glaucoma that can be treated. The elevated IOP occurs due to the inability of accumulated aqueous humor (AQH) to egress from the anterior chamber of the eye due to occlusion of the major outflow pathway, the trabecular meshwork (TM) and Schlemm’s canal (SC). Several different classes of pharmaceutical agents, surgical techniques and implantable devices have been developed to lower and control IOP. First-line drugs to promote AQH outflow via the uveoscleral outflow pathway include FP-receptor prostaglandin (PG) agonists (e.g., latanoprost, travoprost and tafluprost) and a novel non-PG EP2-receptor agonist (omidenepag isopropyl, Eybelis^®). TM/SC outflow enhancing drugs are also effective ocular hypotensive agents (e.g., rho kinase inhibitors like ripasudil and netarsudil; and latanoprostene bunod, a conjugate of a nitric oxide donor and latanoprost). One of the most effective anterior chamber AQH microshunt devices is the Preserflo^® microshunt which can lower IOP down to 10–13 mmHg. Other IOP-lowering drugs and devices on the horizon will be also discussed. Additionally, since elevated IOP is only one of many risk factors for development of glaucomatous optic neuropathy, a treatise of the role of inflammatory neurodegeneration of the optic nerve and retinal ganglion cells and appropriate neuroprotective strategies to mitigate this disease will also be reviewed and discussed.

Twelve-month efficacy and safety of omidenepag isopropyl, a selective EP2 agonist, in open-angle glaucoma and ocular hypertension: the RENGE study

PURPOSE

To assess the long-term safety and efficacy of omidenepag isopropyl (OMDI) 0.002% (a first-in-class, selective, non-prostaglandin, prostanoid EP2 receptor agonist), alone or administered concomitantly with timolol 0.5%, in patients with open-angle glaucoma (OAG, including normal-tension and exfoliation glaucoma) or ocular hypertension (OHT).

STUDY DESIGN

Open-label, multicenter, Phase 3 study (NCT02822729).

METHODS

Patients aged ≥ 20 years, with OAG or OHT, and a baseline diurnal intraocular pressure (IOP) ≥ 16- < 22 mmHg (Group 1) or ≥ 22- ≤ 34 mmHg (Groups 2 and 3) were enrolled. All patients (N = 125) received OMDI 0.002% once daily. Group 3 also received timolol 0.5% twice daily. IOP was measured at baseline and at Weeks 2, 4, 8, 12, 26, 40, and 52.

RESULTS

Significant reductions in mean diurnal IOP from baseline occurred at every visit (P < 0.0001). Mean ± SE diurnal IOP reduction at Week 52 was -3.7 ± 0.3 mmHg (Group 1), -5.6 ± 0.5 mmHg (Group 2), and -8.4 ± 0.6 mmHg (Group 3). Most adverse events (AEs) were mild, and no serious treatment-related AEs were reported. Conjunctival hyperemia (incidence: monotherapy [Groups 1 and 2], 18.8%; concomitant [Group 3], 45.0%) and macular edema (ME)/cystoid macular edema (CME) (incidence: monotherapy, 11.8%; concomitant, 15.0%) occurred most frequently. All treatment-related ME/CME cases occurred in pseudophakic eyes and responded to standard-of-care treatment and study drug discontinuation.

CONCLUSIONS

In this study, OMDI 0.002%, alone or administered concomitantly with timolol 0.5%, resulted in sustained IOP reduction over 52 weeks in patients with OAG or OHT. Concomitant treatment resulted in increased efficacy and increased incidence of conjunctival hyperemia.

Effects of selective EP2 receptor agonist, omidenepag, on trabecular meshwork cells, Schlemm's canal endothelial cells and ciliary muscle contraction

This study investigated the effects of omidenepag (OMD), a novel selective EP2 receptor agonist, on human trabecular meshwork (HTM) cells, monkey Schlemm’s canal endothelial (SCE) cells, and porcine ciliary muscle (CM) to clarify the mechanism of intraocular pressure (IOP) reduction involving conventional outflow pathway. In HTM and SCE cells, the effects of OMD on transforming growth factor-β2 (TGF-β2)-induced changes were examined. The expression of actin cytoskeleton and extracellular matrix (ECM) proteins, myosin light chain (MLC) phosphorylation in HTM cells were evaluated using real-time quantitative PCR, immunocytochemistry, and western blotting. The expression of barrier-related proteins, ZO-1 and β-catenin, and permeability of SCE cells were evaluated using immunocytochemistry and transendothelial electrical resistance. The CM contraction was determined by contractibility assay. OMD significantly inhibited expression of TGF-β2 induced mRNA, protein, and MLC-phosphorylation on cytoskeletal and ECM remodeling in the HTM dose dependently. In SCE cells, OMD suppressed TGF-β2-induced expression of the barrier-related proteins and decreased SCE monolayer permeability. OMD at 3 µM significantly inhibited CM contraction, however, the effect was not significant at lower concentrations. IOP lowering effect of OMD through conventional outflow pathway is exerted by increasing outflow facilities with the modulation of TM cell fibrosis and SCE cell permeability.

Screening of the Drug-Induced Effects of Prostaglandin EP2 and FP Agonists on 3D Cultures of Dexamethasone-Treated Human Trabecular Meshwork Cells

The objective of the current study was to perform a screening of the drug-induced effects of the prostaglandin F2α (PGF2α) and EP2 agonist, omidenepag (OMD), using two- and three-dimensional (2D and 3D) cultures of dexamethasone (DEX)-treated human trabecular meshwork (HTM) cells. The drug-induced effects on 2D monolayers were characterized by measuring the transendothelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC)–dextran permeability, the physical properties of 3D spheroids, and the gene expression of extracellular matrix (ECM) molecules, including collagen (COL) 1, 4 and 6, and fibronectin (FN), α smooth muscle actin (αSMA), a tissue inhibitor of metalloproteinase (TIMP) 1–4, matrix metalloproteinase (MMP) 2, 9 and 14 and endoplasmic reticulum (ER) stress-related factors. DEX induced a significant increase in TEER values and a decrease in FITC–dextran permeability, respectively, in the 2D HTM monolayers, and these effects were substantially inhibited by PGF2α and OMD. Similarly, DEX also caused decreased sizes and an increased stiffness in the 3D HTM spheroids, but PGF2α or OMD had no effects on the stiffness of the spheroids. Upon exposure to DEX, the following changes were observed: the upregulation of COL4 (2D), αSMA (2D), and TIMP4 (2D and 3D) and the downregulation of TIMP1 and 2 (3D), MMP2 and 14 (3D), inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 (ATF6) (2D), and glucose regulator protein (GRP)78 (3D). In the presence of PGF2α or OMD, the downregulation of COL4 (2D), FN (3D), αSMA (2D), TIMP3 (3D), MMP9 (3D) and the CCAAT/enhancer-binding protein homologous protein (CHOP) (2D), and the upregulation of TIMP4 (2D and 3D), MMP2, 9 and 14 (2D), respectively, were observed. The findings presented herein suggest that 2D and 3D cell cultures can be useful in screening for the drug-induced effects of PGF2α and OMD toward DEX-treated HTM cells.

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.

Omidenepag, a Selective, Prostanoid EP2 Agonist, Does Not Suppress Adipogenesis in 3D Organoids of Human Orbital Fibroblasts

Purpose

The purpose of this study was to present the effects of the prostanoid EP2 agonist, omidenepag (OMD) on human orbital fibroblasts (HOFs) using a three-dimension (3D) cell culture.

Methods

During adipogenesis of 3D HOFs organoids, changes in size, lipids staining, mRNA expression of adipogenesis related genes, PPARγ, AP2, and ADIPOQ, and extracellular matrix, collagen 1 (COL 1), COL 4, COL 6, and fibronectin (FN), and stiffness by a micro-squeezer were examined in the presence and absence of either 100 nM bimatoprost acid (BIM-A) or 10, 100, or 10,000 nM OMD.

Results

The size of the 3D organoids increased dramatically during adipogenesis, and these were further enhanced in the presence of OMD in contrast to the BIM-A induced suppression effect. The intensity of lipid staining and the mRNA expression of PPARγ were significantly increased upon adipogenesis, and both or latter was markedly inhibited in the presence of OMD or BIM-A, respectively. AP2 expression was also upregulated by adipogenesis, and was further enhanced by BIM-A. The adipogenesis-induced downregulation of COL 1 and FN, or the upregulation of the expression of COL 4 and COL 6 were all suppressed in the presence of BIM-A. In contrast, OMD caused similar effects on COL 4, COL 6, or FN expression, but caused a significant increase in COL 1 expression. Stiffness was significantly increased upon adipogenesis, and was further increased or substantially decreased by BIM-A or OMD, respectively.

Conclusions

The present study indicates that the FP2 agonist, OMD, had different effects on 3D HOFs organoids, as compared to BIM-A.

Translational Relevance

The current study suggests that OMD may not induce deepening of upper eyelid sulcus (DUES).

A Randomized Phase 2 Trial Comparing Omidenepag Isopropyl 0.002% Once and Twice Daily in Subjects With Primary Open-angle Glaucoma or Ocular Hypertension (SPECTRUM-6)

PRCIS

No significant difference was found between the intraocular pressure (IOP) lowering of omidenepag isopropyl 0.002% once daily (QD) and twice daily (BID). However, adverse events (AEs) were higher in the BID arm; thus, QD dosing is the preferred dosing frequency for further investigation.

PURPOSE

This phase 2, randomized, double-masked, parallel-arm, multicenter study (NCT03858894) was conducted in the United States to examine whether the efficacy and safety of omidenepag isopropyl 0.002% BID dosing was superior to QD dosing in subjects with primary open-angle glaucoma or ocular hypertension.

METHODS

Randomized subjects (1:1) received omidenepag isopropyl 0.002% QD (n=50) or BID (n=48) for 6 weeks (after a ≤4-week washout period). IOP was measured at 8:00 am, 12:00 pm, and 4:00 pm at baseline and weeks 2 and 6. The primary efficacy endpoint was IOP at each timepoint at weeks 2 and 6. AEs were evaluated.

RESULTS

Baseline mean diurnal IOP (±SD) post washout was 25.4±2.9 mm Hg (BID) and 24.6±1.9 mm Hg (QD). At weeks 2 and 6, clinically significant IOP reductions from baseline were observed for omidenepag isopropyl BID and QD treatments. Least-squares mean (±SE) IOP differences (BID versus QD) were not statistically significant (week 2: 0.44±0.68 to 1.08±0.65 mm Hg; week 6: 0.36±0.63 to 0.68±0.68 mm Hg) at any timepoint (all P > 0.05). AEs were 3-fold greater in the BID arm (41.7%; QD: 14.0%); the most frequently reported AE was conjunctival/ocular hyperemia (BID: 22.9%; QD: 2.0%). Five subjects discontinued omidenepag isopropyl prematurely, 4 of 5 owing to AEs (BID: 4; QD: 0).

CONCLUSION

In this study, the benefit-risk profile of omidenepag isopropyl 0.002% QD was more favorable than the benefit-risk profile of BID. This difference was driven by a higher incidence of local tolerability issues in the BID arm.

Simultaneous Use of ROCK Inhibitors and EP2 Agonists Induces Unexpected Effects on Adipogenesis and the Physical Properties of 3T3-L1 Preadipocytes

To elucidate the additive effects of an EP2 agonist, omidenepag (OMD) or butaprost (Buta) on the Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor, ripasudil (Rip) on adipose tissue, two- or three-dimension (2D or 3D) cultures of 3T3-L1 cells were analyzed by lipid staining, the mRNA expression of adipogenesis-related genes, extracellular matrix (ECM) molecules including collagen (Col) -1, -4 and -6, and fibronectin (Fn), and the sizes and physical properties of 3D organoids, as measured by a micro-squeezer. The results indicate that adipogenesis induced (1) an enlargement of the 3D organoids; (2) a substantial enhancement in lipid staining as well as the expression of the Pparγ, Ap2 and Leptin genes; (3) a significant softening of the 3D organoids, the effects of which were all enhanced by Rip except for Pparγ expression; and (4) a significant downregulation in Col1 and Fn, and a significant upregulation in Col4, Col6, the effects of which were unchanged by Rip. When adding the EP2 agonist to Rip, (1) the sizes of the 3D organoids were reduced substantially; (2) lipid staining was increased (OMD), or decreased (Buta); (3) the stiffness of the 3D organoids was substantially increased in Buta; (4-1) the expression of Pparγ was suppressed (2D, OMD) or increased (2D, Buta), and the expressions of Ap2 were downregulated (2D, 3D) and Leptin was increased (2D) or decreased (3D), (4-2) all the expressions of four ECM molecules were upregulated in 2D (2D), and in 3D, the expression of Col1, Col4 was upregulated. The collective findings reported herein indicate that the addition of an EP2 agonist, OMD or Buta significantly but differently modulate the Rip-induced effects on adipogenesis and the physical properties of 2D and 3D cultured 3T3-L1 cells.

Additive Intraocular Pressure-Lowering Effects of a Novel Selective EP2 Receptor Agonist, Omidenepag Isopropyl, Combined with Existing Antiglaucoma Agents in Conscious Ocular Normotensive Monkeys

Purpose: To investigate the intraocular pressure (IOP)-lowering effects of omidenepag isopropyl (OMDI), a potent and highly selective prostanoid EP2 receptor agonist, as a potential first-line ocular hypotensive agent when combined with existing antiglaucoma agents in conscious ocular normotensive monkeys. Methods: Male cynomolgus monkeys were examined under conscious conditions. OMDI ophthalmic solution alone was topically applied to an eye or combined with other ophthalmic solutions at 5-min intervals. The contralateral eye was left untreated. IOP was measured before and at 2, 4, 6, and 8 h after instillation. Results: Topical application of OMDI to the eye resulted in statistically significant IOP reduction, which lasted for at least 6 h. The IOP-lowering effects of OMDI concomitantly administered with any of the tested antiglaucoma agents (timolol, brinzolamide, netarsudil, ripasudil, and brimonidine) were greater than those of OMDI alone. Furthermore, these enhanced IOP responses to their concomitant use were statistically significant compared with those of the tested antiglaucoma agents alone. Any combination of OMDI with the tested agents did not lead to serious abnormalities either systemically or locally in the eye. Conclusions: We demonstrated that OMDI has additive IOP-lowering effects when administered in combination with various antiglaucoma agents, namely, β-adrenergic antagonist, carbonic anhydrase inhibitor, Rho-associated coiled-coil containing protein kinase inhibitors, and α2-adrenergic agonist. These results suggest that OMDI provides additional clinical benefits because of its unique mechanisms of action when combination therapy is required.

Mechanical stretch induces Ca2+ influx and extracellular release of PGE2 through Piezo1 activation in trabecular meshwork cells

The trabecular meshwork (TM) constitutes the main pathway for aqueous humor drainage and is exposed to complex intraocular pressure fluctuations. The mechanism of homeostasis in which TM senses changes in intraocular pressure and leads to normal levels of outflow resistance is not yet well understood. Previous reports have shown that Piezo1, a mechanically-activated cation channel, is expressed in TM and isolated TM cells. Therefore, we tested hypothesis that Piezo1 may function in response to membrane tension and stretch in TM. In human trabecular meshwork (hTM) cells, PIEZO1 was showed to be abundantly expressed, and Piezo1 agonist Yoda1 and mechanical stretch caused a Piezo1-dependent Ca²⁺ influx and release of arachidonic acid and PGE₂. Treatment with Yoda1 or PGE₂ significantly inhibited hTM cell contraction. These results suggest that mechanical stretch stimuli in TM activates Piezo1 and subsequently regulates TM cell contraction by triggering Ca²⁺ influx and release of arachidonic acid and PGE₂. Thus, Piezo1 could acts as a regulator of intraocular pressure (IOP) within the conventional outflow pathway and could be a novel therapeutic strategy to modulate IOP in glaucoma patients.

Prostaglandin F2α and EP2 agonists, and a ROCK inhibitor modulate the formation of 3D organoids of Grave's orbitopathy related human orbital fibroblasts

3D organoid cultures were used to elucidate the periocular effects of several anti-glaucoma drugs including a prostaglandin F2α analogue (bimatoprost acid; BIM-A), EP2 agonist (omidenepag; OMD) or a Rho-associated coiled-coil containing protein kinase (ROCK) inhibitor (ripasudil; Rip) on Grave's orbitopathy (GO) related orbital fatty tissue. 3D organoids were prepared from GO related human orbital fibroblasts (GHOFs) obtained from patients with GO. The effects of either 100 nM BIM-A, 100 nM OMD or 10 μM Rip on the 3D GHOFs organoids were examined with respect to organoid size, physical properties by a micro-squeezer, and the mRNA expression of extracellular matrix (ECM) proteins including collagen (COL) 1, COL 4, COL 6, and fibronectin (FN), ECM regulatory genes including lysyl oxidase (LOX), Connective Tissue Growth Factor (CTGF) and inflammatory cytokines including interleukin-1β (IL1β) and interleukin-6 (IL6). The size of the 3D GHOFs organoids decreased substantially in the presence of BIM-A, but also increased substantially in the presence of the others (OMD or Rip). The physical stiffness of the 3D GHOFs organoids was significantly decreased by Rip. BIM-A caused significantly the down-regulation of three ECM genes, Col 1, Col 6 and Fn, and two ECM regulatory genes and the up-regulation of IL6. In the presence of OMD, two ECM genes, Col 1 and Fn, and LOX were significantly down-regulated but IL1β and IL6 were significantly up-regulated. In the case of Rip, Col 1, FN and CTGF were significant down-regulated. Our present findings indicate that anti-glaucoma drugs modulate the structures and physical properties 3D GHOFs organoids in different manners by modifying the gene expressions of ECM, ECM regulatory factors and inflammatory cytokines. The results indicate that the benefits and demerits of anti-glaucoma medications need to be scrutinized carefully, in cases of patients with GO.

Omidenepag Isopropyl Versus Latanoprost in Primary Open-Angle Glaucoma and Ocular Hypertension: The Phase 3 AYAME Study

PURPOSE

To evaluate the efficacy and safety of omidenepag isopropyl (OMDI), a selective, non-prostaglandin, prostanoid EP2 receptor agonist, in Japanese patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT).

DESIGN

Phase III, randomized, investigator-masked, active-controlled, parallel-group, noninferiority study (ClinicalTrials.govNCT02623738).

METHODS

After a washout period of 1-4 weeks, eligible patients were randomized (1:1) to OMDI 0.002% or latanoprost 0.005% once daily for 4 weeks. Intraocular pressure (IOP) was measured at 9:00 AM, 1:00 PM, and 5:00 PM at weeks 1, 2, and 4. The primary endpoint was the change from baseline in mean diurnal IOP at week 4. The noninferiority margin for OMDI versus latanoprost was 1.5 mm Hg. Adverse events (AEs) were recorded.

RESULTS

Of the 190 patients randomized, 189 had at least 1 post-baseline IOP measurement. At baseline, patients who received OMDI or latanoprost had a mean ± SD diurnal IOP of 23.78 ± 1.73 mm Hg and 23.40 ± 1.51 mm Hg, respectively. At week 4, least-squares mean ± SE reduction in IOP from baseline with OMDI (-5.93 ± 0.23 mm Hg) was noninferior to that of latanoprost (-6.56 ± 0.22 mm Hg; 95% confidence interval between groups: 0.01-1.26). The most frequently reported treatment-related ocular AEs (OMDI vs latanoprost) were conjunctival hyperemia (23/94 patients [24.5%] vs 10/96 patients [10.4%]), corneal thickening (11/94 patients [11.7%] vs 1/96 patients [1.0%]), and punctate keratitis (0/94 patients vs 5/96 patients [5.2%]). No serious AEs were observed in either group, and there were no discontinuations related to the study drug.

CONCLUSIONS

OMDI 0.002% was noninferior to latanoprost 0.005% in reducing IOP in patients with OHT or POAG and was well tolerated.

The role of EP2 receptors in mediating the ultra-long-lasting intraocular pressure reduction by JV-GL1

BACKGROUND

A single application of JV-GL1 substantially lowers non-human primate intraocular pressure (IOP) for about a week, independent of dose. This highly protracted effect does not correlate with its ocular biodisposition or correlate with the once-daily dosing regimen for other prostanoid EP₂ receptor agonists such as trapenepag or omidenepag. The underlying pharmacological mechanism for the multiday extended activity of JV-GL1 is highly intriguing. The present studies were intended to determine EP₂ receptor involvement in mediating the long-term ocular hypotensive activity of JV-GL1 by using mice genetically deficient in EP₂ receptors.

METHODS

The protracted IOP reduction produced by JV-GL1 was investigated in C57BL/6J and EP₂ receptor knock-out mice (B6.129-Ptger2^tm1Brey /J; EP₂KO). Both ocular normotensive and steroid-induced ocular hypertensive (SI-OHT) mice were studied. IOP was measured tonometrically under general anaesthesia. Aqueous humour outflow facility was measured ex vivo using iPerfusion in normotensive C57BL/6J mouse eyes perfused with 100 nM de-esterified JV-GL1 and in SI-OHT C57BL/6J mouse eyes that had received topical JV-GL1 (0.01%) 3 days prior.

RESULTS

Both the initial 1-day and the protracted multiday effects of JV-GL1 in the SI-OHT model for glaucoma were abolished by deletion of the gene encoding the EP₂ receptor. Thus, JV-GL1 did not lower IOP in SI-OHT EP₂KO mice, but in littermate SI-OHT EP₂WT control mice, JV-GL1 statistically significantly lowered IOP for 4-6 days.

CONCLUSIONS

Both the 1-day and the long-term effects of JV-GL1 on IOP are entirely EP₂ receptor dependent.

Medical anti-glaucoma therapy: Beyond the drop

Barriers to effective medical therapy are numerous and include difficulties with effective and sustained control of intraocular pressure (IOP) and adherence to prescribed anti-glaucoma drop regimens. In an effort to circumvent these challenges, a number of new anti-glaucoma therapies with sustained effects have emerged. Methods for sustained delivery of prostaglandin analogs are being intensely investigated and many are in human clinical trials. Intracameral devices include the following: Allergan's Durysta^™ Bimatoprost SR, Envisia Therapeutics' ENV515 travoprost implant, Glaukos' iDose^™ , Ocular Therapeutix's OTX-TIC travoprost implant, and Santen's polycaprolactone implant with PGE2-derivative DE-117. Other prostaglandin-based technologies include Allergan's bimatoprost ring (placed in the conjunctival fornix), Ocular Therapeutics' OTX-TP intracanalicular travoprost implant, subconjunctival latanoprost in a liposomal formulation, and the PGE2 derivative PGN 9856-isopropyl ester that is applied to the periorbital skin. Exciting breakthroughs in gene therapy include using viral vectors to correct defective genes such as MYOC or to modulate gonioimplant fibrosis, CRISPR technology to edit MYOC or to alter aquaporin to reduce aqueous humor production, and siRNA technology to silence specific genes. Stem cell technology can repopulate depleted tissues or, in the case of Neurotech's Renexus® NT-501 intravitreal implant, serve as a living drug delivery device that continuously secretes neurotrophic factors. Other unique approaches involve nanotechnology, nasal sprays that deliver drug directly to the optic nerve and noninvasive alternating current stimulation of surviving cells in the optic nerve. Over time these modalities are likely to challenge the preeminent role that drops currently play in the medical treatment of glaucoma in animals.

Short-Term Efficacy and Safety of Omidenepag Isopropyl in Patients with Normal-Tension Glaucoma

Purpose

To retrospectively evaluate the short-term efficacy of omidenepag isopropyl (EYBELIS 0.002%) by assessing its intraocular pressure (IOP)-lowering capability and safety in patients with normal-tension glaucoma (NTG).

Patients and Methods

Fifty-four NTG patients (54 eyes) who were newly administrated with omidenepag isopropyl were enrolled in the study. The subjects comprised 22 men and 32 women, and the mean age of the subjects was 55.0 ± 14.1 years. The mean deviation value using the Humphrey visual field test program (30–2 SITA Standard) was −5.03 ± 3.38 dB. The following data were retrieved from the medical records and used for retrospective analyses: IOP at baseline 1–2 months and 3–4 months after administration. The frequency of non-responder patients who had less than 10% IOP reduction was evaluated. Patients were observed for adverse reactions and dropouts at each time point.

Results

IOP at baseline, after 1–2 months and after 3–4 months was 15.7 ± 2.6 mmHg, 13.5 ± 2.3 mmHg, and 13.6 ± 2.4 mmHg, respectively. There was a significant decrease in IOP after administration (p<0.0001). Eleven patients (22.4%) were non-responders. Adverse reactions occurred in 4 patients (7.4%), including conjunctival hyperemia in 3 patients (after 1 week, 2 weeks, and 1 month, respectively) and eye pain in 1 patient (after 1 month). Five patients (9.3%) dropped out of the study because of an adverse reaction in 3 patients, insufficient IOP reduction in 1 patient, and discontinuation of follow-up of 1 patient at our institution.

Conclusion

After administration of omidenepag isopropyl, IOP in patients with NTG was significantly decreased. However, adverse reactions occurred in 7.4% of patients.