A Small-Molecule Pan-Id Antagonist Inhibits Pathologic Ocular Neovascularization.

Id helix-loop-helix (HLH) proteins (Id1-4) bind E protein bHLH transcription factors, preventing them from forming active transcription complexes that drive changes in cell states. Id proteins are primarily expressed during development to inhibit differentiation, but they become re-expressed in adult tissues in diseases of the vasculature and cancer. We show that the genetic loss of Id1/Id3 reduces ocular neovascularization in mouse models of wet age-related macular degeneration (AMD) and retinopathy of prematurity (ROP). An in silico screen identifies AGX51, a small-molecule Id antagonist. AGX51 inhibits the Id1-E47 interaction, leading to ubiquitin-mediated degradation of Ids, cell growth arrest, and reduced viability. AGX51 is well-tolerated in mice and phenocopies the genetic loss of Id expression in AMD and ROP models by inhibiting retinal neovascularization. Thus, AGX51 is a first-in-class compound that antagonizes an interaction formerly considered undruggable and that may have utility in the management of multiple diseases.

Patterns of Early and Delayed Visual Response to Ranibizumab Treatment for Neovascular Age-Related Macular Degeneration.

IMPORTANCE: Understanding the range of temporal responses to ranibizumab is critical for the assessment of individualized treatment regimens for neovascular age-related macular degeneration. OBJECTIVE: To examine patterns of visual and anatomical response to ranibizumab treatment. DESIGN, SETTING, AND PARTICIPANTS: This study is a retrospective subanalysis of HARBOR (a phase 3, double-masked, multicenter, randomized, active treatment-controlled study of the efficacy and safety of 0.5 mg and 2.0 mg ranibizumab administered monthly or on an as-needed basis (PRN) in patients with subfoveal neovascular age-related macular degeneration). A total of 1097 patients with neovascular age-related macular degeneration were randomized to intravitreal ranibizumab, 0.5 or 2.0 mg, administered monthly or as needed (PRN) with monthly monitoring. Of the 1097 patients, 1057 were included in the analysis for early responders (best-corrected visual acuity [BCVA] obtained at baseline and month 3), and 988 patients were included in the analysis for delayed responders (BCVA obtained at baseline, month 3, and month 12). The HARBOR study began July 7, 2009, with the primary 12-month end point completed on August 5, 2011, ongoing to 24 months. Data analysis for the subgroup was performed from January 4, 2013, through December 17, 2015. INTERVENTIONS: Patients were categorized based on BCVA outcomes as early 15-letter responders (gained ≥15 letters from baseline at month 3) or delayed 15-letter responders (did not gain ≥15 letters from baseline at month 3 but did so at month 12). MAIN OUTCOMES AND MEASURES: Changes from baseline in BCVA and central foveal thickness (CFT). RESULTS: In total, 266 early and 135 delayed 15-letter responders were identified. In the 0.5-mg monthly, 0.5-mg PRN, 2.0-mg monthly, and 2.0-mg PRN treatment groups, 63 (24.0%) of 263, 65 (24.6%) of 264, 68 (25.7%) of 265, and 70 (26.4%) of 265 patients were early responders, respectively, and 40 (16.3%) of 246, 31 (12.6%) of 247, 35 (14.1%) of 248, and 29 (11.7%) of 247 patients were delayed responders, respectively. By month 12, early vs delayed responders in the PRN treatment groups received 7.5 vs 7.4 ranibizumab injections, respectively (P = .84). More than 80% of early responders receiving PRN treatment maintained 15-letter or greater gains at month 24. At baseline, early vs delayed responders had worse BCVA (49.8 vs 55.4 letters; P < .001) and greater CFT (374.9 vs 339.0 µm; P = .02), although anatomical results were comparable by month 3 (CFT, 187.7 vs 188.9 µm). CONCLUSIONS AND RELEVANCE: Improvement of 15 letters or more from baseline occurred in 266 (25.2%) of 1057 patients within 3 months of beginning ranibizumab treatment, whereas an additional 135 (13.7%) of 988 patients achieved this gain by 12 months. The 2 cohorts had similar anatomical temporal response patterns. PRN treatment with monthly monitoring was effective in maintaining early vision gains and allowing delayed vision gains. These results suggest that vision improvement can continue in some patients after macular edema resolves and CFT decreases stabilize.

Future Perspectives: Agents on the Horizon.

As demonstrated in the previous chapters of this textbook, retinal pharmacotherapeutics is a rapidly developing area. The enormous burden of disease in an aging population will hopefully be met by significant improvements in our understanding and treatment of disease processes such as age-related macular degeneration (AMD) and diabetic retinopathy. This chapter will provide perspectives on select anti-angiogenic drugs currently in development, as well as therapies directed against the complement cascade for the treatment of AMD, and an anti-inflammatory monoclonal antibody for the treatment of diabetic macular edema, among others, that have not been discussed elsewhere in this book. The mechanism of action of a number of drugs under discussion differs enough to have the potential to control neovascularization in several different ways, potentially allowing for more effective management of this process with fewer treatments.

Prevention of ocular scarring after glaucoma filtering surgery using the monoclonal antibody LT1009 (Sonepcizumab) in a rabbit model.

PURPOSE: Excessive scarring leading to failure of the filtering bleb continues to be a major problem after glaucoma filtration surgery. This study examines the antifibrotic effects of the anti-S1P monoclonal antibody LT1009 (Sonepcizumab) in prolonging bleb survival in a rabbit model of glaucoma filtering surgery. METHODS: The frequency of LT1009 dosage was determined initially using an enzyme-linked immunosorbent assay assay measuring LT1009 eye tissue retention in 6 New Zealand White rabbits. A further 21 New Zealand White rabbits underwent glaucoma filtering surgery. Bleb tissues were observed and compared clinically and histologically. The duration of bleb elevation was compared among LT1009, balanced saline solution (BSS) negative control, and mitomycin-C (MMC)-positive control. RESULTS: The mean duration of bleb survival was 28.5±8.5 days for rabbits receiving injections of LT1009, 21.0±5.6 days for those receiving injections of BSS, and 33.8±5.6 days for rabbits receiving MMC. Analysis of variance with post hoc testing suggests a statistically significant trend of improvement in bleb duration for LT1009 when compared with BSS controls. Nonpainful, upper eyelid edema was noted after 5 injections of LT1009, which resolved over a 10-day period. MMC eyes developed avascular conjunctivas with areas of thinning and sparse cellularity, whereas the conjunctiva of LT1009 and BSS eyes remained relatively normal. CONCLUSIONS: The monoclonal antibody LT1009 demonstrated a longer duration of bleb elevation than BSS control without adverse conjunctival effects associated with MMC. However, after multiple doses LT1009 use was associated with short-term upper eyelid edema.

Anatomical benefit from ranibizumab treatment of predominantly classic neovascular age-related macular degeneration in the 2-year anchor study.

PURPOSE: To compare lesion anatomical responses to ranibizumab versus verteporfin photodynamic therapy (PDT) in the ANCHOR (Anti-VEGF Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization [CNV] in Age-Related Macular Degeneration) study. METHODS: In this 2-year, Phase III, randomized, multicenter, double-masked trial, 423 patients received ranibizumab (0.3 or 0.5 mg) monthly + sham PDT or PDT + monthly sham injection. Photodynamic therapy (or sham PDT) was administered at Day 0 and then quarterly as needed. A central reading center assessed fundus photography and fluorescein angiography images. A subset (n = 61) had optical coherence tomography assessments. Main outcome measures included mean change from baseline at Months 12 and 24 for area of classic CNV and total area of leakage from CNV. RESULTS: At Months 12 and 24, ranibizumab was superior to PDT (P < 0.0001) for mean changes from baseline in total area of lesion, CNV area, and total area CNV leakage. Month 12 optical coherence tomographies showed greater center point thickness decrease from baseline with ranibizumab than with PDT (P = 0.0003). Ranibizumab benefits over PDT were evident by 3 months (fluorescein angiography) and 7 days (optical coherence tomography). CONCLUSION: Differences between the PDT and the ranibizumab groups in lesion anatomical outcomes were early, sustained, and favored ranibizumab.

Vitreous nonsteroidal antiinflammatory drug concentrations and prostaglandin E2 levels in vitrectomy patients treated with ketorolac 0.4%, bromfenac 0.09%, and nepafenac 0.1%.

PURPOSE: To assess vitreous concentrations of nonsteroidal antiinflammatory drugs (NSAIDs) and prostaglandin E(2) in patients treated with NSAIDs before vitrectomy. METHODS: This was an investigator-masked, randomized, multicenter study. Patients received ketorolac 0.4% 4 times a day, bromfenac 0.09% 2 times a day, nepafenac 0.1% 3 times a day, or no NSAID for 3 days before surgery. Nonsteroidal antiinflammatory drugs and prostaglandin E(2) levels were determined in vitreous samples collected at the beginning of surgery. RESULTS: Thirty-one patients were included in the analyses. The mean (SD) vitreous concentrations were as follows: ketorolac 2.8 (3.2) ng/mL, bromfenac 0.96 (0.31) ng/mL, nepafenac 1.1 (0.6) ng/mL, and amfenac 2.0 (0.8) ng/mL aligned with the initial concentrations of the topical NSAIDs. Mean (SD) vitreous prostaglandin E(2) levels of the control patients and those treated with ketorolac 0.4%, bromfenac 0.09%, or nepafenac 0.1% were 270.6 (91.7) pg/mL, 189.6 (50.2) pg/mL, 247.2 (38.3) pg/mL, and 267.7 (99.7) pg/mL, respectively. Patients treated with ketorolac 0.4% had significantly lower prostaglandin E(2) levels than those treated with no NSAID (P = 0.047) or nepafenac 0.1% (P = 0.028). CONCLUSION: All three NSAIDs penetrated into the vitreous cavity. Topical therapy with ketorolac may lower preoperative vitreous prostaglandin E(2) levels, which may have a clinical impact on the management of prostaglandin-mediated diseases, including cystoid macular edema.

Blockade of sphingosine-1-phosphate reduces macrophage influx and retinal and choroidal neovascularization.

Sphingosine-1-phosphate (S1P) is a bioactive lipid molecule that stimulates endothelial cell migration, proliferation, and survival in vitro, and tumor angiogenesis in vivo. In this study, we used a humanized monoclonal antibody (sonepcizumab) that selectively binds S1P to investigate its role in retinal and choroidal neovascularization (NV). Intraocular injection of sonepcizumab significantly reduced macrophage influx into ischemic retina and strongly suppressed retinal NV in mice with oxygen-induced ischemic retinopathy. In mice with laser-induced rupture sites in Bruch's membrane, intraocular injection of sonepcizumab significantly reduced the area of choroidal NV and concomitantly reduced fluorescein leakage from the remaining choroidal NV. Four weeks after intraocular injection of up to 1.8 mg of the sonepcizumab in non-human primates, electroretinograms and fluorescein angiograms were normal, and light microscopy of ocular sections showed no evidence of structural damage. These data show for the first time that S1P stimulates both choroidal and retinal NV and suggest that sonepcizumab could be considered for evaluation in patients with choroidal or retinal NV.

Anti-sphingosine-1-phosphate monoclonal antibodies inhibit angiogenesis and sub-retinal fibrosis in a murine model of laser-induced choroidal neovascularization.

The efficacy of novel monoclonal antibodies that neutralize the pro-angiogenic mediator, sphingosine-1-phosphate (S1P), were tested using in vitro and in vivo angiogenesis models, including choroidal neovascularization (CNV) induced by laser disruption of Bruch's membrane. S1P receptor levels in human brain choroid plexus endothelial cells (CPEC), human lung microvascular endothelial cells, human retinal vascular endothelial cells, and circulating endothelial progenitor cells were examined by semi-quantitative PCR. The ability of murine or humanized anti-S1P monoclonal antibodies (mAbs) to inhibit S1P-mediated microvessel tube formation by CPEC on Matrigel was evaluated and capillary density in subcutaneous growth factor-loaded Matrigel plugs was determined following anti-S1P treatment. S1P promoted in vitro capillary tube formation in CPEC consistent with the presence of cognate S1P(1-5) receptor expression by these cells and the S1P antibody induced a dose-dependent reduction in microvessel tube formation. In a murine model of laser-induced rupture of Bruch's membrane, S1P was detected in posterior cups of mice receiving laser injury, but not in uninjured controls. Intravitreous injection of anti-S1P mAbs dramatically inhibited CNV formation and sub-retinal collagen deposition in all treatment groups (p<0.05 compared to controls), thereby identifying S1P as a previously unrecognized mediator of angiogenesis and subretinal fibrosis in this model. These findings suggest that neutralizing S1P with anti-S1P mAbs may be a novel method of treating patients with exudative age-related macular degeneration by reducing angiogenesis and sub-retinal fibrosis, which are responsible for visual acuity loss in this disease.

Sphingosine-1-phosphate (S1P) is a novel fibrotic mediator in the eye.

Sphingosine-1-phosphate (S1P) is a pleiotropic lysolipid that has recently been implicated in the regulation of tissue fibrosis. However, the fibrogenic potential of S1P in the eye has not previously been investigated. In the current study, we evaluated cells from the anterior and posterior segments of the eye for the presence of S1P and their potential ability to produce and respond to S1P. In addition, we investigated the regulatory role of S1P as a mediator of proliferation, cellular transformation and pro-fibrotic protein expression in human retinal pigmented epithelial cells. Expression of S1P receptors and sphingosine kinases (the enzymes that produce S1P) was examined using RT-PCR, and intracellular localization of S1P was examined using immunoblotting, immunohistochemistry and ELISA in primary human retinal pigmented epithelial (RPE) cells, primary human conjunctival fibroblasts (ConF), and primary human corneal fibroblasts (CF). RPE cell proliferation was determined using an MTT-based cell proliferation assay, and RPE myofibroblast transformation, collagen type I production and profibrotic protein expression were assessed using immunofluorescence, ELISA and immunoblot. S1P(1-3, 5) receptors and sphingosine kinases 1 and 2 were expressed and intracellular pools of S1P were detected in RPE cells, ConF and CF. S1P stimulated RPE cell proliferation in a dose- and time-dependent manner. S1P induced myofibroblast transformation of RPE cells, as indicated by increased alpha-smooth muscle actin (alpha-SMA) expression and its incorporation into prominent stress fibers, and promoted collagen type I production. S1P stimulated the expression of plasminogen activator inhibitor-1 (PAI-1) and heat shock protein 47 (HSP47), two proteins that are linked to increased tissue fibrosis. Combined, these data demonstrate that RPE cells, ConF and CF from the human eye not only have the molecular ability to produce and respond to S1P, but also contain S1P. Furthermore, S1P promotes proliferation, myofibroblast transformation, collagen production and pro-fibrotic protein expression by human RPE cells. These data suggest that S1P is a previously unrecognized mediator of profibrotic cellular function and signaling in the eye.