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.

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.

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.

PEONY Study: Testing How Well and How Safely Omidenepag Isopropyl Eye Drops Treat People with Glaucoma or Ocular Hypertension Compared with Latanoprost. Who took part in the study? Three hundred and seventy participants average age of 57 years, from 34 centers across four Asian countries who had glaucoma or high pressure in both eyes were randomly divided into two groups. One group (185 people; 50%) was given OMDI, and the other group (185 people; 50%) latanoprost for 3 months. The intraocular pressure of both eyes was measured in all participants at three time points (9 AM, 1 PM, and 5 PM) after 1 week, 6 weeks, and 3 months of treatment. The primary endpoint was the average of the daily eye pressure after 3 months of treatment. The safety of OMDI was also assessed. Study results. After 3 months of treatment, OMDI decreased the eye pressure by 29%. This was similar to latanoprost, which decreased the eye pressure by 31% over the same time period. OMDI was safe and well tolerated by those participants who received it. The most common side-effect in people receiving OMDI or latanoprost was conjunctival hyperemia (red eye) (experienced by 22 people receiving OMDI, and 10 people receiving latanoprost). Conclusions After 3 months of use, OMDI was found to safely reduce high eye pressure to a similar level as latanoprost in Asian people with glaucoma or high eye pressure.

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.

Omidenepag Isopropyl in Latanoprost Low/Nonresponders With Primary Open Angle Glaucoma or Ocular Hypertension: A Phase 3, Nonrandomized, Two-Phase, Open-Label Study.

PRCIS: This study demonstrates the efficacy and safety of once-daily 0.002% omidenepag isopropyl (OMDI) in patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT) who do not respond or respond poorly to latanoprost. PURPOSE: The purpose of this study was to evaluate the intraocular pressure (IOP)-lowering efficacy and safety of OMDI in latanoprost low/nonresponders with POAG or OHT. MATERIALS AND METHODS: Phase 3, nonrandomized, 2-phase, open-label, multicenter study (NCT03697811) in the United States. Key inclusion criteria included individuals aged 18 years or above, POAG or OHT diagnosis in both eyes, IOP ≥22 mm Hg in ≥1 eye, and ≤34 mm Hg in both eyes at all time points. Overall, 107 patients were enrolled; 104 completed treatment. Included a screening period (≤35-day washout period and 8-week latanoprost run-in period) and a 3-month treatment period comprising one drop of OMDI 0.002% once daily in both eyes. The primary study endpoint was changed from baseline in the mean diurnal (MD) IOP at month 3. Safety endpoints included incidence of adverse events, serious adverse events, and adverse drug reactions. RESULTS: At baseline (visit 4), 75 (70.1%) patients had POAG, 32 (29.9%) had OHT, and 68 (63.6%) had prior use of prostaglandin/prostaglandin analogs (37.4% of whom used latanoprost). The mean (SD) baseline MD IOP was 23.34 mm Hg (2.12). The mean (SD) 3-month (visit 7) MD IOP change from baseline (following latanoprost run-in period and OMDI treatment period) was an additional decrease of 2.96 mm Hg (2.83) ( P <0.0001). No significant safety issues were reported during OMDI treatment. CONCLUSIONS: These data demonstrate OMDI efficacy and safety in latanoprost low/nonresponders with POAG or OHT, suggesting OMDI is a treatment option in the patient population in this study.

Phase 2b, Randomized, 3-Month, Dose-Finding Study of Sepetaprost in Patients with Primary Open-Angle Glaucoma or Ocular Hypertension: The ANGEL Study.

Purpose: This phase 2b, randomized, observer-masked, placebo- and active-controlled, parallel-group, multinational (USA and Japan), multicenter study (NCT03216902) assessed the optimal dose of sepetaprost ophthalmic solution in patients with primary open-angle glaucoma or ocular hypertension. Methods: After washout, patients ≥18 years (USA) or ≥20 years of age (Japan) received once-daily sepetaprost for 3 months [0.0005% (n = 43); 0.001% (n = 43); 0.002% (n = 44); and 0.003% (n = 45)], latanoprost 0.005% (n = 44) or placebo until week 6, followed by sepetaprost 0.003% until month 3 (n = 22). Safety assessments included adverse event (AE) occurrence. Results: Baseline mean diurnal intraocular pressure (IOP) was 24.3 mmHg for latanoprost and ranged between 24.1 and 24.5 mmHg for the sepetaprost groups. Sepetaprost 0.002% had the lowest IOP at each month 3 time point (9:00 AM; 1:00 PM; 5:00 PM) of all sepetaprost concentrations (mean ± standard error: 17.6 ± 0.5; 17.4 ± 0.4; 16.7 ± 0.4 mmHg); similar values were observed with latanoprost (18.1 ± 0.6; 17.3 ± 0.5; 17.2 ± 0.5 mmHg). A positive dose-response relationship was observed with the 3 lower sepetaprost doses; sepetaprost 0.002% had numerically greater IOP-lowering effects than sepetaprost 0.003%. All sepetaprost doses had statistically significantly greater IOP reductions from baseline versus placebo at week 6 (P < 0.0001). This IOP-lowering effect was consistent between Japan- and USA-based patients. Most AEs were mild and occurred numerically less frequently with sepetaprost 0.002% (34.1%) versus latanoprost (50.0%). The most frequently reported AE was conjunctival hyperemia. Conclusion: In this study, sepetaprost 0.002% was the optimal concentration, showing comparable IOP-lowering efficacy and safety with latanoprost 0.005%. Most AEs were mild; occurrence was numerically lower with sepetaprost 0.002% than latanoprost 0.005%.

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.

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, ß-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.

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.

ARG098, a novel anti-human Fas antibody, suppresses synovial hyperplasia and prevents cartilage destruction in a severe combined immunodeficient-HuRAg mouse model.

BACKGROUND: The anti-human Fas/APO-1/CD95 (Fas) mouse/human chimeric monoclonal IgM antibody ARG098 (ARG098) targets the human Fas molecule. The cytotoxic effects of ARG098 on cells isolated from RA patients, on normal cells in vitro, and on RA synovial tissue and cartilage in vivo using implanted rheumatoid tissues in an SCID mouse model (SCID-HuRAg) were investigated to examine the potential of ARG098 as a therapy for RA. METHODS: ARG098 binding to each cell was analyzed by cytometry. The effects of ARG098 on several cells were assessed by a cell viability assay in vitro. Effects on the RA synovium, lymphocytes, and cartilage were assessed in vivo using the SCID-HuRAg mouse model. RESULTS: ARG098 bound to cell surface Fas molecules, and induced apoptosis in Fas-expressing RA synoviocytes and infiltrating lymphocytes in the RA synovium in a dose-dependent manner. However, ARG098 did not affect the cell viability of peripheral blood mononuclear cells of RA patients or normal chondrocytes. ARG098 also induced apoptosis in RA synoviocytes and infiltrating lymphocytes in the RA synovium in vivo. The destruction of cartilage due to synovial invasion was inhibited by ARG098 injection in the modified SCID-HuRAg mouse model. CONCLUSIONS: ARG098 treatment suppressed RA synovial hyperplasia through the induction of apoptosis and prevented cartilage destruction in vivo. These results suggest that ARG098 might become a new therapy for RA.

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.

Effects of the Selective EP2 Receptor Agonist Omidenepag on Adipocyte Differentiation in 3T3-L1 Cells.

Purpose: We aimed at comparing the effects of omidenepag (OMD) with those of prostaglandin F (FP) receptor agonists (FP agonists) on adipogenesis in mouse 3T3-L1 cells. Methods: To evaluate the agonistic activities of OMD against the mouse EP2 (mEP2) receptor, we determined cAMP contents in mEP2 receptor-expressing CHO cells by using radioimmunoassays. Overall, 3T3-L1 cells were cultured in differentiation medium for 10 days and adipocyte differentiation was assessed according to Oil Red O-stained cell areas. Changes in expression levels of the adipogenic transcription factors Pparg, Cebpa, and Cebpb were determined by using real-time polymerase chain reaction (PCR). OMD at 0.1, 1, 10, and 40 µmol/L, latanoprost free acid (LAT-A) at 0.1 µmol/L, or prostaglandin F2α (PGF2α), at 0.1 µmol/L were added to cell culture media during adipogenesis. Oil Red O-stained areas and expression patterns of transcription factor targets of OMD or FP agonists were compared with those of untreated controls. Results: The 50% effective concentration (EC50) of OMD against the mEP2 receptor was 3.9 nmol/L. Accumulations of Oil Red O-stained lipid droplets were observed inside control cells on day 10. LAT-A and PGF2α significantly inhibited the accumulation of lipid droplets; however, OMD had no effect on this process even at concentrations up to 40 µmol/L. LAT-A and PGF2α significantly suppressed Pparg, Cebpa, and Cebpb gene expression levels during adipocyte differentiation. Conversely, OMD had no obvious effects on the expression levels of these genes. Conclusions: A selective EP2 receptor agonist, OMD, did not affect the adipocyte differentiation in 3T3-L1 cells, whereas FP agonists significantly inhibited this process.

Intraocular pressure-lowering effect of omidenepag isopropyl in latanoprost non-/low-responder patients with primary open-angle glaucoma or ocular hypertension: the FUJI study.

PURPOSE: Omidenepag isopropyl (OMDI) is the prodrug of omidenepag, a selective, non-prostaglandin, prostanoid EP2 receptor agonist, which has been shown to lower intraocular pressure (IOP) in patients with glaucoma and ocular hypertension (OHT). This study evaluated the efficacy and safety of OMDI ophthalmic solution 0.002% in patients with primary open-angle glaucoma or OHT who were non-/low responders to latanoprost. STUDY DESIGN: Open-label, multicenter, Phase 3 study (NCT02822742). METHODS: Following 1-4-week washout, patients were treated with latanoprost ophthalmic solution 0.005% during an 8-week run-in period. Patients with ≤15% IOP reduction at the end of the run-in (indicating non-/low response) received OMDI 0.002% (one drop once daily for 4 weeks). The primary endpoint was the change from baseline in mean diurnal IOP at Week 4. RESULTS: In total, 26 patients were treated with OMDI; two withdrew owing to lack of efficacy. The mean diurnal IOP at baseline (end of latanoprost run-in) was 23.1 mmHg (7.6% IOP reduction from end of washout) indicating non-/low response to latanoprost. After 4 weeks of OMDI treatment, mean diurnal IOP was significantly reduced from baseline (-2.99 mmHg; P < 0.0001). No serious adverse events were reported. Adverse events occurred in five patients (19.2%); adverse drug reactions (anterior chamber cell, conjunctival hyperemia, and erythema of eyelid) occurred in two patients (7.7%) and were mild in severity. CONCLUSIONS: In this study, OMDI 0.002% demonstrated a clinically significant reduction in IOP and was well tolerated in patients with primary open-angle glaucoma and OHT who were non-/low responders to latanoprost.

The Antiglaucoma Agent and EP2 Receptor Agonist Omidenepag Does Not Affect Eyelash Growth in Mice.

Purpose: The present study investigated the effects of the antiglaucoma agent and selective E2 receptor agonist omidenepag isopropyl (OMDI) on eyelash growth in comparison with a prostaglandin analog (prostamide receptor agonist) in mice. Methods: Four-week-old female mice (C57BL/6J) were divided into 3 groups of n = 10 each. The groups were administered 3 µL of 0.003% OMDI solution, the vehicle (negative control), or a 0.03% bimatoprost solution (positive control) on the upper eyelids of the right eyes once daily for 14 days. On the 15th day, all animals were euthanized, and the upper eyelids with eyelashes were fixed with 10% neutral formalin. Eyelashes were evaluated for number, length, and thickness using a stereomicroscope. Specimens were then paraffin-embedded and stained with hematoxylin and eosin, followed by microscopic examination to assess eyelash morphology and growth cycle. Results: Eyelash number (143.5 ± 6.7/eyelid), thickness, and percentage of dermal papilla in the anagen phase in the OMDI group were similar to those observed in the vehicle group (eyelash number, 144.2 ± 5.7/eyelid). In contrast, eyelash number (166.7 ± 7.0/eyelid), thickness, and the percentage of dermal papilla in the anagen phase were significantly greater in the bimatoprost group compared with those of the vehicle group. Conclusions: Unlike existing prostaglandin analogs, our findings indicate that OMDI has no effect on eyelash growth in mice, suggesting that it may be a promising antiglaucoma agent with a reduced number of adverse effects.

Phase 2, Randomized, Dose-finding Studies of Omidenepag Isopropyl, a Selective EP2 Agonist, in Patients With Primary Open-angle Glaucoma or Ocular Hypertension.

PRéCIS:: Three randomized, multicenter studies demonstrated the stable intraocular pressure-lowering effects and tolerability of omidenepag isopropyl in patients with primary open-angle glaucoma and ocular hypertension; 0.002% was identified as the optimal dose for further investigation. PURPOSE: The purpose of this study was to assess the safety and efficacy of omidenepag isopropyl, a selective EP2 agonist, and to determine the optimal dose for further investigation. PATIENTS AND METHODS: Three randomized, controlled, masked, multicenter studies were conducted in United States (study 1, NCT01868126; study 2, NCT02179008) and Japan (study 3, NCT02623738). Patients were randomized to 1 of 7 omidenepag isopropyl concentrations (0.0003%, 0.001%, 0.0012%, 0.0016%, 0.002%, 0.0025%, and 0.003%), latanoprost (0.005%), or placebo, 1 drop once daily for 28 days (studies 1 and 3) or 90 days (study 2). Primary endpoints were the observed mean diurnal intraocular pressure (IOP) and IOP at each time point on the final visit (studies 1 and 2) and change from baseline in mean diurnal IOP at week 4 (study 3). RESULTS: IOP-lowering effects of omidenepag isopropyl 0.0003% to 0.002% increased dose-dependently. Omidenepag isopropyl 0.002% and 0.0025% resulted in clinically relevant mean diurnal IOP reductions from baseline that were similar to those of latanoprost and superior to placebo (P<0.005). Maximum reductions had already been achieved by week 1, and stable IOP-lowering effects were observed at all postbaseline time points up to 3 months. Most adverse events (AEs) were mild. Conjunctival hyperemia was the most frequently reported AE, the incidence of which increased dose-dependently. The safety profiles of omidenepag isopropyl 0.002% and 0.0025% were similar, with a slightly lower incidence of AEs in the 0.002% group. CONCLUSIONS: Omidenepag isopropyl demonstrated stable IOP-lowering effects and was well tolerated; 0.002% was identified as the optimal dose for phase 3 investigation.

Pharmacokinetics, Safety, and Intraocular Pressure-Lowering Profile of Omidenepag Isopropyl, a Selective, Nonprostaglandin, Prostanoid EP2 Receptor Agonist, in Healthy Japanese and Caucasian Volunteers (Phase I Study).

Purpose: Omidenepag isopropyl (OMDI) is a prodrug of OMD, a selective, nonprostaglandin, prostanoid EP2 receptor agonist. This phase I study aimed to investigate the pharmacokinetic properties, safety, and intraocular pressure (IOP)-lowering efficacy of OMDI. Methods: Fourteen healthy male volunteers (7 Japanese and 7 Caucasian) 20-35 years of age received 1 drop of OMDI 0.0025% at 9:00 h in both eyes for 7 days. Blood samples were taken predose and up to 8 h postdose on days 1, 3, and 7. The plasma concentration of OMD was determined using high-performance liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters measured included the maximum plasma concentration (Cmax) and the half-life (t½) of OMD. IOP, adverse events (AEs), ophthalmic examinations, vital signs, and laboratory values were assessed. Results:Cmax for all subjects was reached after 10-15 min and decreased with a t½ of ∼30 min. Ad hoc statistical analyses found significant differences in some pharmacokinetic parameters between Japanese and Caucasian subjects, likely due to differences in body weight. These differences reduced over 7 days of dosing and were not thought to be clinically meaningful. There was no OMD accumulation after 7 days of repeated dosing. Mean IOP was reduced by ∼4-5 mmHg between baseline and 2 h postdose, remaining stable from day 3 onward. All AEs were mild and considered treatment related. Conclusions: Pharmacokinetic parameters of OMD were similar between Japanese and Caucasian subjects. There was no accumulation of OMD after 7 days of dosing. OMDI was well tolerated and demonstrated clinically significant IOP reductions.

Identification of a Selective, Non-Prostanoid EP2 Receptor Agonist for the Treatment of Glaucoma: Omidenepag and its Prodrug Omidenepag Isopropyl.

EP2 receptor agonists are expected to be effective ocular hypotensive agents; however, it has been suggested that agonism to other EP receptor subtypes may lead to undesirable effects. Through medicinal chemistry efforts, we identified a scaffold bearing a (pyridin-2-ylamino)acetic acid moiety as a promising EP2-selective receptor agonist. (6-((4-(Pyrazol-1-yl)benzyl)(pyridin-3-ylsulfonyl)aminomethyl)pyridin-2-ylamino)acetic acid 13ax (omidenepag, OMD) exerted potent and selective activity toward the human EP2 receptor (h-EP2). Low doses of omidenepag isopropyl (OMDI), a prodrug of 13ax, lowered intraocular pressure (IOP) in ocular normotensive monkeys. OMDI was selected as a clinical candidate for the treatment of glaucoma.

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

PURPOSE: To investigate the mechanism of the intraocular pressure (IOP)-lowering effect of a novel selective prostaglandin E2 receptor 2 (EP2) receptor agonist, omidenepag isopropyl (OMDI). METHODS: The effect of OMDI on IOP and aqueous humor dynamics was evaluated in cynomolgus monkeys with unilateral laser-induced ocular hypertension. In a crossover manner, the hypertensive eye of each monkey was dosed once daily with 20 µL of either 0.002% OMDI or vehicle. On day 7 of dosing, IOP was measured by pneumatonometry, aqueous humor flow and outflow facility were evaluated by fluorophotometry, and uveoscleral outflow was calculated mathematically. Treatments were compared by paired t-tests. RESULTS: OMDI at 0.002% significantly lowered IOP by 27%, 35%, and 44% at 0.5, 1.5, and 4 h after the last dosing, respectively. There was no difference in aqueous humor flow between vehicle and OMDI treatments. When comparing OMDI to the vehicle treatment, outflow facility and uveoscleral outflow were significantly (P < 0.05) increased by 71% and 176%, respectively. CONCLUSIONS: OMDI, a novel IOP-lowering compound, reduced IOP by increasing outflow facility and uveoscleral outflow in nonhuman primates.

Pharmacologic Characterization of Omidenepag Isopropyl, a Novel Selective EP2 Receptor Agonist, as an Ocular Hypotensive Agent.

Purpose: The objective of this study was to investigate the pharmacologic characteristics of omidenepag isopropyl (OMDI), a compound developed as a novel intraocular pressure (IOP)-lowering agent, with better IOP control and fewer side effects than other prostanoid receptor agonists such as prostaglandin F receptor (FP) agonists. Methods: Binding activities of OMDI and its hydrolyzed form, omidenepag (OMD), to human recombinant prostanoid receptors (DP1-2, EP1-4, FP, and IP) were evaluated. Based on these binding assays, the agonistic activities of OMDI and OMD were further evaluated using cultured cells expressing selected prostanoid receptors. The pharmacokinetics of OMDI after topical administration was assessed in rabbits by measurement of the concentrations of both OMDI and OMD in aqueous humor. The ocular hypotensive effect of OMDI was evaluated in ocular normotensive rabbits, dogs, and both ocular normotensive and hypertensive monkeys. Results: OMD was determined to be a selective EP2 receptor agonist. OMDI weakly bound to EP1; however, the agonistic activity of OMDI to this receptor was not demonstrated in the functional assay. After topical administration of OMDI, OMD was detected in aqueous humor whereas OMDI was not detectable. OMDI significantly lowered IOP in both ocular normotensive and hypertensive animals. The significant ocular hypotensive effects of OMDI were demonstrated by both single and repeated dosing, and its effective duration suggests sufficient efficacy by once-daily dosing. Conclusions: These studies demonstrated that OMDI is hydrolyzed in the eye to OMD, an EP2 receptor agonist, with a significant ocular hypotensive effect in both ocular normotensive and hypertensive animal models.

Effects of repeated administrations of tafluprost, latanoprost, and travoprost on optic nerve head blood flow in conscious normal rabbits.

PURPOSE: The aim of this study was to evaluate and compare the effects of repeated administrations of three prostaglandin F(2alpha) analogs (tafluprost, latanoprost, and travoprost) on optic nerve head (ONH) blood flow in normal rabbits. METHODS: Male Dutch rabbits were housed under a 12-h light-dark cycle for use in this study. A quantitative index of blood flow, the squared blur rate (SBR), was determined using laser speckle flowgraphy. Saline, 0.0015% tafluprost, 0.005% latanoprost, or 0.004% travoprost (each 50 microL) was topically administered into the left eye once daily for 28 days. ONH blood flow was measured before the start at the course of treatment (baseline), and on day 14 and/or day 28 [measurements being made at 0, 30, and/or 60 min after drugs application on day 14 and/or day 28]. Heart rate was also measured at these time points. RESULTS: Tafluprost, latanoprost, and travoprost each increased the ONH blood flow at all measurement points on day 14 and/or day 28. The 0 min SBR value on day 14 was greater than the baseline SBR value by 8.7% + or - 4.4% for tafluprost and by 5.8% + or - 1.7% for latanoprost. The 0 min SBR value on day 28 was greater than the baseline SBR value by 11.9% + or - 3.9% for tafluprost, by 7.2% + or - 4.3% for latanoprost, and by 6.7% + or - 3.5% for travoprost. The increasing state of the ONH blood flow continued within 60 min after a topical administration of tafluprost, latanoprost, or travoprost. Tafluprost, latanoprost, and travoprost did not change heart rate (vs. the baseline value) at any measurement points. CONCLUSIONS: Repeated topical administration of any of the three prostaglandin F(2alpha) analogs increased ONH blood flow in rabbits, without changing heart rate. The increase in ONH blood flow induced by tafluprost was greater than that induced by latanoprost (P = 0.086) or travoprost (P = 0.037) at 60 min on day 28.