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.

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.

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 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.

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.

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.

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.

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.