Suprachoroidal Injection of Triamcinolone Acetonide Suspension: Ocular Pharmacokinetics and Distribution in Rabbits Demonstrates High and Durable Levels in the Chorioretina.

Purpose: To compare ocular pharmacokinetics (PK), systemic absorption, and injectability of triamcinolone acetonide (TA) suprachoroidal (SC) and intravitreal (IVT) suspensions. Methods: New Zealand White (NZW) rabbits received a bilateral injection of 4 mg TA injectable suspension, TRI (TRIESENCE ®; Alcon) through either microneedle-based SC or standard IVT injection. Another group of NZW rabbits received a bilateral SC injection (4 mg) of either TRI or a proprietary TA suspension for SC use, CLS-TA (Clearside Biomedical). Blood and ocular tissues were analyzed for TA over 3 months. Separately, injectability of TRI and CLS-TA through a proprietary SC delivery system (SCS Microinjector®; Clearside Biomedical) was compared using microinjector syringe-plunger glide force measurement. Results: Suprachoroidal delivery of TRI, compared with IVT-TRI, resulted in ∼12-fold higher exposure in the retinal pigment epithelium-choroid-sclera, and comparable exposure in the retina. Conversely, SC-TRI, compared to IVT-TRI, resulted in 460-, 34-, and 22-fold lower exposure in the lens, iris-ciliary body, and vitreous humor, and negligible exposure in the aqueous humor. SC injection of either CLS-TA or TRI resulted in comparable and sustained ocular TA levels. Plasma TA levels were generally undetectable in both studies. A significantly greater and more variable glide force was measured for TRI vs. CLS-TA. Conclusions: Suprachoroidal delivery of TA enabled high and durable TA levels targeted to the chorioretina with limited anterior segment exposure. SC delivery of either CLS-TA or TRI resulted in comparable ocular PK profiles with low systemic exposure; however, CLS-TA required lower and less variable glide force than TRI, potentiating more consistent, controlled administration.

Dose Uniformity of Loteprednol Etabonate (Submicron) Ophthalmic Gel 0.38% Compared with Prednisolone Acetate Ophthalmic Suspension 1.

INTRODUCTION: Loteprednol etabonate (submicron) ophthalmic gel 0.38% (LE SM gel 0.38%) is a corticosteroid formulation designed to retain the nonsettling characteristics of loteprednol etabonate ophthalmic gel 0.5%, but with reduced drug particle size to improve ocular penetration, allowing for reduced dosing frequency. This study compared the dose uniformity of LE SM gel 0.38% with branded and generic prednisolone acetate (PA) 1% suspensions under simulated in-use dosing conditions. METHODS: Drug concentrations in drops of LE SM gel 0.38% and PA 1% suspensions, expressed from bottles that were shaken or not shaken, were determined during 2 weeks of simulated on-label dosing (LE SM gel 0.38%: three times daily; PA suspensions: four times daily). Sedimentation of drug particles was assessed for each product using dispersion analysis. RESULTS: The mean (SD) percent declared drug concentration of LE SM gel 0.38% over 2 weeks was 103.2% (1.3%) when the drug was dispensed from shaken bottles and 103.3% (1.5%) when dispensed from unshaken bottles. However, for branded and generic PA suspensions, mean (SD) percent declared concentrations were 102.2% (1.4%) and 98.3% (2.9%), respectively, when dispensed from shaken bottles; and 89.2% (18.6%) and 78.3% (13.5%), respectively, when dispensed from unshaken bottles. Dispersion analysis showed that drug particles in LE SM gel 0.38% remained fully suspended under accelerated sedimentation conditions, whereas both branded and generic PA suspension drug particles settled out of suspension. CONCLUSIONS: LE SM gel 0.38% delivered the drug consistently at the declared concentration over the entire 2 weeks of simulated in-use dosing conditions, regardless of whether the drug was dispensed from shaken or unshaken bottles. However, both branded and generic PA suspensions required the bottle to be shaken to provide a consistent drug concentration.

Loteprednol etabonate (submicron) ophthalmic gel 0.38% dosed three times daily following cataract surgery: integrated analysis of two Phase III clinical studies.

PURPOSE: To evaluate the efficacy and safety of a submicron formulation of loteprednol etabonate (LE) gel 0.38% instilled three times daily (TID) compared with vehicle for the treatment of inflammation and pain following cataract surgery with intraocular lens implantation, integrated across two multicenter, double-masked, randomized, parallel-group, Phase III studies. PATIENTS AND METHODS: Subjects ≥18 years of age with anterior chamber (AC) cells ≥grade 2 (6-15 cells) on day 1 after cataract surgery were randomized to receive 1 drop of LE gel 0.38% TID, twice daily (not reported/analyzed herein), or vehicle instilled in the study eye for 14 days. Primary endpoints were the proportion of subjects with resolution of AC cells and grade 0 (no) pain at postoperative day 8. Safety outcomes included adverse events (AEs), ocular signs, fundoscopy results, visual acuity, intraocular pressure (IOP), and tolerability (drop comfort and ocular symptoms). RESULTS: The integrated intent-to-treat population included 742 subjects (LE gel 0.38% TID, n=371; vehicle, n=371). Significantly more subjects in the LE gel 0.38% TID group compared with the vehicle group had complete resolution of AC cells (29.6% vs 15.1%) and grade 0 pain (74.4% vs 48.8%) at day 8 (P<0.0001 for both). LE gel 0.38% TID was safe and well tolerated, with only 1 LE-treated subject experiencing an IOP elevation ≥10 mm Hg. Most treatment-related AEs were mild and occurred less frequently with LE gel 0.38% than with vehicle. The majority (>75%) of subjects in each treatment group reported no drop discomfort. There were no reports of blurred vision with LE gel. CONCLUSION: The results of this integrated analysis indicate that LE (submicron) gel 0.38% administered TID is safe and effective for the treatment of ocular inflammation and pain following cataract surgery, with minimal risk of IOP elevation.

Rheological Properties, Dissolution Kinetics, and Ocular Pharmacokinetics of Loteprednol Etabonate (Submicron) Ophthalmic Gel 0.38.

Purpose: To evaluate rheological properties, in vitro dissolution, and in vivo ocular pharmacokinetics of loteprednol etabonate (LE) (submicron) ophthalmic gel 0.38%. Methods: The viscosity of the LE gel 0.38% formulation was measured with a controlled stress rheometer. Dissolution kinetics were evaluated in a fixed-volume and flow-through assay. Rabbits received a single instillation of LE (submicron) gel 0.38% (both eyes), and concentrations of LE in ocular tissues were determined through 24 h by liquid chromatography with tandem mass spectrometry. Where indicated, comparators included micronized LE gel 0.38%, 0.5% (Lotemax® gel), and 0.75%. Results: LE (submicron) gel 0.38% exhibited shear-thinning characteristics similar to LE gel 0.5% with nearly identical yield stress. LE (submicron) gel 0.38% released 2.6-fold more LE into the dissolution medium than micronized LE gel 0.5% over 30 s in the fixed-volume dissolution assay, and submicron LE attained higher concentrations of dissolved LE than micronized LE gel 0.38% in the flow-through dissolution assay. In rabbits, the maximal concentration and area-under-the-curve over 24 h for LE in aqueous humor were 2.5- and 1.8-fold higher, respectively, for LE (submicron) gel 0.38% versus micronized LE gel 0.5% (both P < 0.001). Pharmacokinetic parameters were similar for most other tissues. Conclusions: LE (submicron) gel 0.38% demonstrated similar rheological properties to micronized LE gel 0.5% but faster dissolution, thus providing similar or higher LE concentrations in the aqueous humor, cornea, and iris-ciliary body after ocular dosing in rabbits despite a lowered concentration of drug in the formulation.

Bepotastine besilate ophthalmic solution 1.5% for alleviating nasal symptoms in patients with allergic conjunctivitis.

BACKGROUND: Bepotastine besilate ophthalmic solution (BBOS) 1.5% is a topical antihistamine for the treatment of ocular itching associated with allergic conjunctivitis (AC). Allergic rhinitis and AC are common comorbid conditions. We explored the efficacy of BBOS 1.5% in alleviating nasal symptoms in an integrated analysis of two Phase III conjunctival allergen challenge (CAC) studies and a Phase IV environmental allergen study. METHODS: In the Phase III trials, a CAC was performed 15 minutes, 8 hours, and 16 hours following ocular instillation of BBOS 1.5% (n=78) or placebo (n=79), and subjects evaluated nasal symptoms. In the environmental study, subjects instilled BBOS 1.5% (n=123) or placebo (n=122) twice daily and nasal symptoms were evaluated over 2 weeks. RESULTS: In the Phase III trials, BBOS 1.5% had reduced CAC-induced nasal congestion and pruritus at 15 minutes and 8 hours postdosing and rhinorrhea and a non-ocular composite-symptom score (sum of nasal scores plus ear or palate pruritus) at all time points postdosing (all P≤0.01 vs placebo). In the Phase IV environmental study, BBOS 1.5% reduced sneezing and nasal pruritus over 2 weeks and median number of days to improvement of nasal pruritus and total nasal symptom score (sum for rhinorrhea, sneezing, nasal pruritus, and nasal congestion; P≤0.04 vs placebo). Additionally, investigator-reported improvement in overall ocular (pruritus, hyperemia, tearing) and nasal symptoms was greater with BBOS 1.5% vs placebo (P≤0.03). CONCLUSION: Results of these exploratory analyses indicate that topical ocular BBOS 1.5% reduced nasal symptoms, supporting its use for alleviating rhinitis symptoms associated with AC.

Brimonidine Ophthalmic Solution 0.025% for Reduction of Ocular Redness: A Randomized Clinical Trial.

SIGNIFICANCE: The α2-adrenergic receptor agonist brimonidine has been reported to induce conjunctival blanching in cataract, strabismus, laser refractive, and filtration procedures. Clinicians are often faced with red eyes with no apparent underlying pathology. Low-dose brimonidine reduced ocular redness in such subjects with efficacy maintained over 1 month and negligible rebound redness. PURPOSE: The aim of this study was to evaluate the safety and efficacy of brimonidine tartrate ophthalmic solution 0.025% for the treatment of ocular redness. METHODS: In this single-center, double-masked, phase 3 clinical trial, adult subjects with baseline redness of more than 1 unit in both eyes (0- to 4-unit scale) were randomized 2:1 to brimonidine 0.025% or vehicle. A single dose was administered in-office (day 1); thereafter subjects instilled treatment four times a day for 4 weeks, with clinic visits on days 15, 29, and 36 (7 days post-treatment). Efficacy end points included investigator-evaluated redness 5 to 240 minutes post-instillation on day 1 (primary); investigator-evaluated change from baseline 1, 360, and 480 minutes post-instillation on day 1, and 1 and 5 minutes post-instillation on days 15 and 29; total clearance of redness, and subject-assessed redness. Safety/tolerability measures included adverse events, rebound redness, and drop comfort. RESULTS: Sixty subjects were randomized (n = 40 brimonidine, n = 20 vehicle). Investigator-assessed redness was lower with brimonidine versus vehicle over the 5- to 240-minute post-instillation period (mean [SE], 0.62 [0.076] vs. 1.49 [0.108]; P < .0001) and at each time point within that period (P < .0001). At 1, 360, and 480 minutes post-instillation, respectively, the mean differences (95% confidence interval) between treatments were -0.73 (-1.05 to -0.41), -0.57 (-0.84 to -0.29), and -0.39 (-0.67 to -0.10), respectively. No tachyphylaxis was evident with brimonidine on days 15 and 29, and minimal rebound redness was observed following discontinuation. Adverse events were infrequent, and brimonidine was rated as very comfortable. CONCLUSIONS: Brimonidine 0.025% appeared safe and effective for reduction of ocular redness, with an 8-hour duration of action, no evidence of tachyphylaxis, and negligible rebound redness.

The Role of Nitric Oxide in the Intraocular Pressure Lowering Efficacy of Latanoprostene Bunod: Review of Nonclinical Studies.

Latanoprostene bunod (LBN) is a topical ophthalmic therapeutic for the reduction of intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension (OHT). LBN is composed of latanoprost acid (LA) linked to a nitric oxide (NO)-donating moiety and is the first NO-releasing prostaglandin analog to be submitted for marketing authorization in the United States. The role of latanoprost in increasing uveoscleral outflow of aqueous humor (AqH) is well established. Herein, we review findings from nonclinical studies, which evaluated the role of NO in the IOP-lowering efficacy of LBN. Pharmacokinetic studies in rabbits and corneal homogenates indicate that LBN is rapidly metabolized to LA and butanediol mononitrate (BDMN). NO is subsequently released by BDMN as shown by increased cyclic guanosine monophosphate (cGMP) levels in (1) the AqH and iris-ciliary body after administration of LBN in rabbits and in (2) human trabecular meshwork (TM) cells after incubation with LBN. LBN reduced myosin light chain phosphorylation, induced cytoskeletal rearrangement, and decreased resistance to current flow to a greater extent than latanoprost in TM cells, indicating that NO released from LBN elicited TM cell relaxation. LBN also lowered IOP to a greater extent than latanoprost in FP receptor knockout mice, rabbits with transient OHT, glaucomatous dogs, and primates with OHT. Along with results from a Phase 2 clinical study in which treatment with LBN 0.024% resulted in greater IOP-lowering efficacy than latanoprost 0.005%, these data indicate that LBN has a dual mechanism of action, increasing AqH outflow through both the uveoscleral (using LA) and TM/Schlemm's canal (using NO) pathways.

Impact of the Topical Ophthalmic Corticosteroid Loteprednol Etabonate on Intraocular Pressure.

Corticosteroids are a mainstay therapeutic option for the treatment of ocular inflammation. However, safety remains a concern for clinicians, particularly with long-term use. Though highly effective at suppressing inflammatory and allergic responses, topical ophthalmic corticosteroids carry an inherent risk of side effects, including elevated intraocular pressure (IOP), a risk factor for the development of glaucoma. The corticosteroid loteprednol etabonate (LE) contains an ester rather than a ketone at the C-20 position, minimizing the potential for side effects, including IOP elevation. In early pivotal clinical trials of LE ophthalmic suspension for conjunctivitis (allergic, giant papillary), anterior uveitis, and post-operative inflammation, LE had minimal impact on IOP over short-term (<28 days) and long-term (≥28 days) use. Since then, new LE formulations-including a gel, an ointment, and a suspension of LE in combination with tobramycin-have become commercially available. Multiple studies evaluating the safety and efficacy of LE for inflammatory conditions have been reported, including those requiring longer-term treatment such as photorefractive keratectomy, corneal transplantation, and dry eye disease. We review the available published data on the effect of LE on IOP and report on the cumulative incidence of clinically significant IOP elevations (≥10 mm Hg from baseline) with short-term and long-term LE use. In all studies, LE consistently demonstrated a low propensity to elevate IOP, regardless of formulation, dosage regimen, or treatment duration, including in known steroid responders. The cumulative proportion of patients exhibiting clinically significant IOP increases was 0.8% (14/1725 subjects) in studies evaluating short-term LE treatment and 1.5% (21/1386 subjects) in long-term studies. Furthermore, use of LE was associated with significantly lower rates of IOP elevation ≥10 mm Hg as compared to prednisolone acetate or dexamethasone (when used in combination with tobramycin). The cumulative data to date substantiates a favorable IOP-safety profile for LE with both short-term and long-term use.

Regulation of Endothelin-1-Induced Trabecular Meshwork Cell Contractility by Latanoprostene Bunod.

PURPOSE: Previous in vivo studies demonstrated that latanoprostene bunod (LBN), a nitric oxide (NO)-donating prostaglandin F2α receptor agonist, results in greater intraocular pressure (IOP) lowering than latanoprost. The present series of investigations compared the effects of LBN and latanoprost on primary human trabecular meshwork cell (HTMC) contractility and underlying signaling pathways to determine whether LBN might mediate this additional IOP lowering via the conventional outflow pathway. METHODS: The effect of LBN (1-100 µM) on HTMC cGMP levels was determined by ELISA with or without the soluble guanylate cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). Endothelin-1 (ET-1) was used to induce HTMC contractility. To determine the effect of LBN on myosin light chain-2 (MLC-2) phosphorylation, HTMCs were pretreated with 10 to 60 µM LBN for 1 hour and then ET-1 for 5 minutes. MLC-2 phosphorylation was determined by Western blotting. Effects of LBN (30 and 45 µM) on ET-1-induced filamentous (F)-actin cytoskeletal stress fibers and the focal adhesion associated protein vinculin were determined by confocal microscopy. ET-1-induced HTMC monolayer resistance in the presence of LBN (45 µM) was determined by electrical cell substrate impedance sensing, as an indicator of cell contractility. Latanoprost and SE 175 (an NO donor which releases NO on reductive transformation within the cells) were used as comparators in all studies. RESULTS: LBN (1-100 µM) significantly increased cGMP levels in a dose-dependent manner, with a half maximal effective concentration (EC50) of 1.5 ± 1.3 µM, and with maximal effect similar to that of 100 µM SE 175. In contrast, latanoprost caused a minimal increase in cGMP levels at 100 µM only. The cGMP elevation induced by LBN or SE 175 was abolished by ODQ and was therefore sGC-dependent. The two NO donors SE 175 and LBN elicited a reduction in ET-1-induced MLC-2 phosphorylation that was significantly greater than that mediated by latanoprost in HTMCs. SE 175 (100 µM) and LBN (30 or 45 µM) caused a dramatic reduction in ET-1-induced actin stress fibers and vinculin localization at focal adhesions, whereas 45 µM latanoprost was without observable effect. SE 175 reduced ET-1-induced increases in HTMC resistance in a dose-dependent manner. A synergistic effect on reduction of HTMC resistance was observed when latanoprost and SE 175 doses were given together. LBN significantly reduced ET-1-induced HTMC monolayer resistance increases to a greater extent than latanoprost, indicating a greater reduction in cell contractility with LBN. CONCLUSIONS: LBN, SE 175, and latanoprost caused relaxation of ET-1-contracted HTMCs. The effect on HTMC relaxation observed with LBN was significantly greater in magnitude than that observed with latanoprost or SE 175. Data indicate that the NO-donating moiety of LBN mediates HTMC relaxation through activation of the cGMP signaling pathway and a subsequent reduction in MLC-2 phosphorylation. These findings suggest that increased conventional outflow facility may mediate the additional IOP-lowering effects of LBN over that of latanoprost observed in in vivo studies.

Mapracorat, a selective glucocorticoid receptor agonist, upregulates RelB, an anti-inflammatory nuclear factor-kappaB protein, in human ocular cells.

Selective glucocorticoid receptor agonists (SEGRAs) are a new class of compounds under clinical evaluation for treatment of ocular inflammation. Widely prescribed therapeutics, such as glucocorticoids, are effective at reducing ocular inflammation, but their long term use predisposes to undesirable side effects. The purpose of this study was to investigate a novel SEGRA, mapracorat (BOL-303242-X), and the differences in mapracorat's mechanism of action compared with traditional steroids (i.e. dexamethasone). Keratocytes from three different humans were cultured and treated with mapracorat or dexamethasone, with and without a strong provoking agent, interleukin (IL)-1ß. The effects of mapracorat compared to dexamethasone were determined by measuring protein levels (Western blotting) and DNA binding (ELISA) for two nuclear factor-kappaB (NF-κB) family members, RelA and RelB. Cytokine production (i.e. IL-6, IL-8, prostaglandin E2 (PGE2)) was characterized by immunoassay. Our findings reveal mechanistic differences between mapracorat and traditional steroid therapies. Mapracorat showed partial attenuation of the classical NF-κB pathway, consistent with traditional steroids. However, mapracorat uniquely potentiated a novel anti-inflammatory mechanism through rapid upregulation of RelB, an anti-inflammatory member of the NF-κB alternative pathway. Mapracorat potently inhibits ocular inflammation in vitro and is a promising new treatment for ocular inflammatory disease. Mapracorat acts, in part, by a novel mechanism via upregulation of RelB in the NF-κB alternative pathway.

Nitric oxide (NO): an emerging target for the treatment of glaucoma.

The predominant risk factor for the progression of glaucoma is an increase in IOP, mediated via a reduction in aqueous outflow through the conventional (trabecular meshwork and Schlemm's canal) outflow pathway. Current IOP lowering pharmacological strategies target the uveoscleral (nonconventional) outflow pathway or aqueous humor production; however, to date no therapy that primarily targets the conventional pathway exists. Nitric oxide (NO) is an intracellular signaling molecule produced by endogenous NO synthases, well-known for its key role in vasodilation, through its action on smooth muscle cells. Under physiological conditions, NO mediates a multitude of diverse ocular effects, including maintenance of IOP. Nitric oxide donors have been shown to mediate IOP-lowering effects in both preclinical models and clinical studies, primarily through cell volume and contractility changes in the conventional outflow tissues. This review is focused on evaluating the current knowledge of the role and mechanism of action of endogenous NO and NO donors in IOP regulation. Data on key additional functions of NO in glaucoma pathology (i.e., ocular blood flow and effects on optic neuropathy) are also summarized. The potential for future therapeutic application of NO in the treatment of glaucoma is then discussed.

Mapracorat, a selective glucocorticoid receptor agonist, causes apoptosis of eosinophils infiltrating the conjunctiva in late-phase experimental ocular allergy.

BACKGROUND: Mapracorat, a novel nonsteroidal selective glucocorticoid receptor agonist, has been proposed for the topical treatment of inflammatory disorders as it binds with high affinity and selectivity to the human glucocorticoid receptor and displays a potent anti-inflammatory activity, but seems to be less effective in transactivation of a number of genes, resulting in a lower potential for side effects. Contrary to classical glucocorticoids, mapracorat displays a reduced ability to increase intraocular pressure and in inducing myocilin, a protein linked to intraocular pressure elevation. Allergic conjunctivitis is the most common form of ocular allergy and can be divided into an early phase, developing immediately after allergen exposure and driven primarily by mast cell degranulation, and a late phase, developing from 6-10 hours after the antigen challenge, and characterized by conjunctival infiltration of eosinophils and other immune cells as well as by the production of cytokines and chemokines. METHODS: In this study, mapracorat was administered into the conjunctival sac of ovalbumin (OVA)-sensitized guinea pigs 2 hours after the induction of allergic conjunctivitis, with the aim of investigating its activity in reducing clinical signs of the late-phase ocular reaction and to determine its mechanism of anti-allergic effects with respect to apoptosis of conjunctival eosinophils and expression of the chemokines C-C motif ligand 5 (CCL5), C-C motif ligand 11 (CCL11), and interleukin-8 (IL-8) and the proinflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α). RESULTS: Mapracorat, administered into the conjunctival sac of OVA-sensitized guinea pigs 2 hours after allergen exposure, was effective in reducing clinical signs, eosinophil infiltration, and eosinophil peroxidase activity in the guinea pig conjunctiva; furthermore, it reduced conjunctival mRNA levels and protein expression of both CCL5 and CCL11. Mapracorat was more effective than dexamethasone in increasing, in conjunctival sections of OVA-treated guinea pigs, apoptotic eosinophils. CONCLUSION: Mapracorat displays anti-allergic properties in controlling the late phase of ocular allergic conjunctivitis and is a promising candidate for the topical treatment of allergic eye disorders.

Anti-allergic effects of mapracorat, a novel selective glucocorticoid receptor agonist, in human conjunctival fibroblasts and epithelial cells.

PURPOSE: To determine the ocular anti-allergic effects of mapracorat, a novel selective glucocorticoid receptor agonist (SEGRA) in primary human conjunctival fibroblasts and epithelial cells. METHODS: Two primary human conjunctival cell types, human conjunctival epithelial cells (HConEpiC) and human conjunctival fibroblasts (HConF), were challenged with interleukin-4 (IL-4) or IL-13 plus tumor necrosis factor-alpha (TNF-α). Luminex technology was used to profile the resulting inflammatory response. The effects of mapracorat on the release of eotaxin and regulated on activation, normal T cell expressed and secreted (RANTES), two allergy-related chemokines, as well as proinflammatory cytokines and intercellular adhesion molecule 1 (ICAM-1) were then determined. Small interfering RNA was used to determine whether the effects of mapracorat were mediated via the glucocorticoid receptor (GR). Dexamethasone was used as the control. RESULTS: IL-13 or IL-4 plus TNF-α in the HConF or HConEpiC significantly increased eotaxin-1 (HConF only), eotaxin-3, RANTES, multiple proinflammatory cytokines, and ICAM-1. Synergistic effects of IL-13 or IL-4 plus TNF-α were observed in the HConEpiC for RANTES and monocyte chemoattractant protein-1, and in the HConF for eotaxin-1, eotaxin-3, and RANTES. Mapracorat significantly reduced IL-4 or IL-13 plus TNF-α-induced cytokine release and ICAM-1 protein in a dose-dependent manner in both cell types, with comparable efficacy to dexamethasone. These effects were mediated through the glucocorticoid receptor (GR), as demonstrated by the reversal of inhibitory effects after silencing of glucocorticoid receptor expression. CONCLUSIONS: Data from these in vitro models indicate that mapracorat is efficacious and potent in reducing IL-4 or IL-13 plus TNF-α-induced release of allergy-related and proinflammatory cytokines from the HConF and the HConEpiC, supporting clinical evaluation of the compound in reducing allergic and inflammatory reactions in allergic conjunctivitis.

Anti-inflammatory and anti-oxidative effects of the green tea polyphenol epigallocatechin gallate in human corneal epithelial cells.

PURPOSE: To determine the anti-inflammatory and anti-oxidant effects of epigallocatechin gallate (EGCG), the major polyphenol component of green tea, in human corneal epithelial cells (HCEpiC). METHODS: HCEpiC were challenged with interleukin-1ß (IL-1ß) for 18 h or hyperosmolarity (440 mOsm) for 24 h. Luminex technology was used to determine the effects of EGCG (0.3-30 µM) on IL-1ß- or hyperosmolar-induced cytokine release into the medium. Cell metabolic activity was measured using the alamarBlue assay. Effects of EGCG on mitogen-activated protein kinase (MAPK) phosphorylation were determined by cell-based enzyme-linked immunosorbent assay (ELISA) and western blotting. Effects of EGCG on nuclear factor kappa B (NFκB) and activator protein-1 (AP-1) transcriptional activity were assessed by reporter gene assay. The effects of EGCG on glucose oxidase (GO)-induced reactive oxygen species (ROS) production was determined using the ROS probe CM-H2DCFDA. RESULTS: Treatment of HCEpiC with 1 ng/ml IL-1ß for 18 h significantly increased release of the cytokines/chemokines granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1), while hyperosmolarity-induced release of IL-6 and MCP-1. When cells were treated with IL-1ß and EGCG or hyperosmolarity and EGCG there was a dose-dependent reduction in release of these cytokines/chemokines, with significant inhibition observed at 3-30 µM. There was no effect of EGCG on cell metabolic activity at any of the doses tested (0.3-30 µM). EGCG significantly inhibited phosphorylation of the MAPKs p38 and c-Jun N-terminal kinase (JNK), and NFκB and AP-1 transcriptional activities. There was a significant dose-dependent decrease in GO-induced ROS levels after treatment of HCEpiC with EGCG. CONCLUSIONS: EGCG acts as an anti-inflammatory and anti-oxidant agent in HCEpiC and therefore may have therapeutic potential for ocular inflammatory conditions such as dry eye.

Nonclinical safety evaluation of boric acid and a novel borate-buffered contact lens multi-purpose solution, Biotrue™ multi-purpose solution.

Multipurpose solutions (MPS) often contain low concentrations of boric acid as a buffering agent. Limited published literature has suggested that boric acid and borate-buffered MPS may alter the corneal epithelium; an effect attributed to cytotoxicity induced by boric acid. However, this claim has not been substantiated. We investigated the effect of treating cells with relevant concentrations of boric acid using two cytotoxicity assays, and also assessed the impact of boric acid on corneal epithelial barrier function by measuring TEER and immunostaining for tight junction protein ZO-1 in human corneal epithelial cells. Boric acid was also assessed in an in vivo ocular model when administered for 28 days. Additionally, we evaluated Biotrue multi-purpose solution, a novel borate-buffered MPS, alone and with contact lenses for ocular compatibility in vitro and in vivo. Boric acid passed both cytotoxicity assays and did not alter ZO-1 distribution or corneal TEER. Furthermore, boric acid was well-tolerated on-eye following repeated administration in a rabbit model. Finally, Biotrue multi-purpose solution demonstrated good ocular biocompatibility both in vitro and in vivo. This MPS was not cytotoxic and was compatible with the eye when administered alone and when evaluated with contact lenses. We demonstrate that boric acid and a borate-buffered MPS is compatible with the ocular environment. Our findings provide evidence that ocular effects reported for some borate-buffered MPS may be incorrectly attributed to boric acid and are more likely a function of the unique combination of ingredients in the MPS formulation tested.

Mapracorat, a novel selective glucocorticoid receptor agonist, inhibits hyperosmolar-induced cytokine release and MAPK pathways in human corneal epithelial cells.

PURPOSE: Increasing evidence suggests that tear hyperosmolarity is a central mechanism causing ocular surface inflammation and damage in dry eye disease. Mapracorat (BOL-303242-X) is a novel glucocorticoid receptor agonist currently under clinical evaluation for use in the treatment of dry eye disease. This study assessed the anti-inflammatory effects of mapracorat in an in vitro osmotic stress model which mimics some of the pathophysiological changes seen in dry eye. METHODS: Human corneal epithelial cells were cultured in normal osmolar media (317 mOsM) or 440 mOsM hyperosmolar media for 24 h. Luminex technology was used to determine the effect of mapracorat on hyperosmolar-induced cytokine release. Effects of mapracorat on mitogen-activated protein kinase (MAPK) phosphorylation were determined by cell based ELISA. Effects of mapracorat on nuclear factor kappa B (NFkappaB) and activator protein-1 (AP-1) transcriptional activity were assessed by reporter gene assay. Dexamethasone was used as a control. RESULTS: Hyperosmolar conditions induced release of the pro-inflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1) from cultured human corneal epithelial cells, and altered the phosphorylation state of p38 and c-Jun N-terminal kinase (JNK) and transcriptional activity of NFkappaB and AP-1. Incubation of cells with mapracorat inhibited hyperosmolar-induced cytokine release with comparable activity and potency as dexamethasone. This inhibition was reversed by the glucocorticoid receptor antagonist mifepristone (RU-486). Increased phosphorylation of p38 and JNK caused by hyperosmolarity was inhibited by mapracorat. Mapracorat also significantly decreased the hyperosmolar-induced increase in NFkappaB and AP-1 transcriptional activity. CONCLUSIONS: Mapracorat acts as a potent anti-inflammatory agent in corneal epithelial cells challenged with osmotic stress, with comparable activity to the traditional steroid dexamethasone. These in vitro data suggest that mapracorat may be efficacious in the treatment of dry eye disease.

Gas6-Axl pathway: the role of redox-dependent association of Axl with nonmuscle myosin IIB.

In vascular smooth muscle cells, Axl is a key receptor tyrosine kinase, because it is upregulated in injury, increases migration and neointima formation, and is activated by reactive oxygen species. Reaction of glutathione with cysteine residues (termed "glutathiolation") is an important posttranslational redox modification that may alter protein activity and protein-protein interactions. To investigate the mechanisms by which reactive oxygen species increase Axl-dependent vascular smooth muscle cell function we assayed for glutathiolated proteins that associated with Axl in a redox-dependent manner. We identified glutathiolated nonmuscle myosin heavy chain (MHC)-IIB as a novel Axl interacting protein. This interaction was specific in that other myosins did not interact with Axl. The endogenous ligand for Axl, Gas6, increased production of reactive oxygen species in vascular smooth muscle cells and also increased the association of Axl with MHC-IIB. Antioxidants ebselen and N-acetylcysteine decreased the association of Axl with MHC-IIB in response to both Gas6 and reactive oxygen species. Blocking the Axl-MHC-IIB interaction with the specific myosin II inhibitor blebbistatin decreased phosphorylation of Axl and activation of extracellular signal-regulated kinase 1/2 and Akt. Association of MHC-IIB with Axl was increased in balloon-injured rat carotid vessels. Finally, expression of MHC-IIB was upregulated in the neointima of the carotid artery after balloon injury similar to upregulation of Axl protein expression, as shown in our previous studies. These results demonstrate a novel interaction between Axl and MHC-IIB in response to reactive oxygen species. This interaction provides a direct link between Axl and molecular motors crucial for directed cell migration, which may mediate increased migration in vascular dysfunction.

Reduced myocilin expression in cultured monkey trabecular meshwork cells induced by a selective glucocorticoid receptor agonist: comparison with steroids.

PURPOSE: To assess in vitro myocilin (MYOC) expression in trabecular meshwork (TM) cells exposed to BOL-303242-X, a selective glucocorticoid receptor (GR) agonist (SEGRA), in comparison with dexamethasone (DEX), and prednisolone acetate (PA). METHODS: After drug treatment of monkey TM cultures, MYOC protein in conditioned media (CM) was measured by Western blot and densitometry. MYOC mRNA levels were analyzed by qRT-PCR. RU-486 was tested for antagonism of MYOC protein expression induced by DEX and BOL-303242-X. RESULTS: Baseline MYOC protein released into CM and MYOC mRNA were detected. DEX or PA elicited dose-dependent increases in MYOC in CM and also in MYOC mRNA. BOL-303242-X effects typified partial agonism, with significantly reduced MYOC protein and mRNA, compared with DEX. Maximum efficacy for BOL-303242-X was 53% of that for DEX. Mean EC(50) across all strains tested was lower, but not significantly different, for BOL-303242-X versus DEX. Compared with DEX, MYOC mRNA levels were significantly lower in BOL-303242-X-treated TM cells at the highest doses tested. EC(50)s for PA were higher than DEX, for both myocilin protein and mRNA. RU-486 displayed a dose-dependent antagonism to drug-induced increases in myocilin levels. CONCLUSIONS: In vitro quantitative assays of myocilin expression in TM cells can be used for characterizing anti-inflammatory drugs that are GR ligands. The results suggest that, compared with traditional ocular steroids, therapeutic doses of BOL-303242-X elicit a reduced myocilin expression profile in TM cells by virtue of the partial agonist properties of this compound.

BOL-303242-X, a novel selective glucocorticoid receptor agonist, with full anti-inflammatory properties in human ocular cells.

PURPOSE: BOL-303242-X is a novel selective glucocorticoid receptor agonist under clinical evaluation for the treatment of inflammatory skin and eye diseases. Data from in vitro and in vivo studies suggest an improved side-effect profile of this compound compared to classical glucocorticoids. The aim of this study was to determine the anti-inflammatory effect of BOL-303242-X in ocular cells. METHODS: Four primary human ocular cell cultures, including human conjunctival fibroblasts (HConFs), human corneal epithelial cells (HCEpiCs), human optic nerve astrocytes (HONAs), and human retinal endothelial cells (HRECs), as well as a human monocytic cell line, THP-1, were challenged with either lipopolysacharide (LPS) or interleukin-1ss (IL-1ss). Luminex technology was used to determine the effect of BOL-303242-X on LPS- or IL-1ss-induced cytokine release and intercellular adhesion molecule-1 (ICAM-1) levels. Effects of BOL-303242-X on nuclear factor kappa B (NFkappaB) and mitogen-activated protein kinase (MAPK) in HCEpiCs were also assessed by measuring inhibitory kappa B protein-alpha (IkappaB-alpha), phosphorylated p65 NFkappaB, and MAPK levels by western blotting. Dexamethasone (DEX) or triamcinolone acetonide (TA) was used as the control. RESULTS: LPS or IL-1ss induced multiple cytokine release in all cell types studied. BOL-303242-X significantly reduced LPS- or IL-1ss-induced inflammatory cytokine release in a dose-dependent manner, including granulocyte colony-stimulating factor (G-CSF), IL-1ss, IL-6, IL-8, IL-12p40, monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-alpha (TNF-alpha). BOL-303242-X showed activity and potency comparable to that observed for DEX or TA. A statistically significant inhibitory effect of BOL-303242-X was observed at doses ranging from 1 to 100 nM in HConFs, HCEpiCs, HONAs, and THP-1. The IC(50) values for these effects were in the low nM range. BOL-303242-X also significantly reduced LPS-induced IL-1ss release and ICAM-1 levels in HRECs. Furthermore, BOL-303242-X inhibited IL-1ss-induced decreases in IkappaB-alpha levels, as well as IL-1ss-induced phosphorylation of NFkappaB, p38, and c-Jun-N-terminal kinase (JNK) MAPKs in HCEpiCs. CONCLUSIONS: BOL-303242-X acts as a potent anti-inflammatory agent in various primary human ocular cells with similar activity and potency compared to classical steroids. Results also suggest that MAPK (p38 and JNK) and NFkappaB signaling pathways are involved in the anti-inflammatory properties of BOL-303242-X in HCEpiCs. An improved side effect profile of this novel SEGRA compound has been reported recently. Thus, BOL-303242-X may provide a new option for the treatment of ophthalmic conditions with an inflammatory component.

Comparison of the effect of multipurpose contact lens solutions on the viability of cultured corneal epithelial cells.

PURPOSE: To determine the effect of four marketed multipurpose contact lens solutions (MPSs) on corneal epithelial cell viability. METHODS: Comparison of the effect of MPS A (Renu MultiPlus, Bausch & Lomb), MPS B (OPTI-FREE Express, Alcon), MPS C (AQuify, CibaVision), and MPS D (OPTI-FREE RepleniSH, Alcon) on cell viability was performed by quantifying cellular ATP content, resazurin reduction, and lactate dehydrogenase (LDH) release in transformed human corneal epithelial cells (HCEpiC) and primary bovine corneal epithelial cells (BCEpiC). RESULTS: Significant reductions in cellular ATP content were observed at 40% solution and above with both MPS B and MPS D, compared to at 100% only for MPS A and MPS C, and similar results were obtained in BCEpiC. Effects on resazurin reduction were also less in HCEpiC exposed to increasing doses of MPS A and MPS C than in cells exposed to MPS B and MPS D. After 15 min, HCEpiC viability measured by both resazurin reduction and cellular ATP levels was significantly lower for cells exposed to MPS B, MPS D, and MPS C, while HCEpiC exposed to MPS A were not affected. MPS B and MPS D reduced cell viability more than MPS A and MPS C over a 2-h time course in both HCEpiC and BCEpiC. CONCLUSIONS: Both MPS B and MPS D can cause large decreases in the viability of cultured corneal epithelial cells even with just a 2h exposure at multiple doses. Significant reduction in cell viability is evident at brief 15-30 min exposures. In contrast, MPS A and MPS C have significantly less effect on the cell viability of corneal epithelial cells at multiple doses, after these short exposure times.