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Background: Pegaptanib, an anti-vascular endothelial growth factor therapy, was evaluated in the treatment of neovascular age-related macular degeneration. Methods: We conducted two concurrent, prospective, randomized, double-blind, multicenter, dose-ranging, controlled clinical trials using broad entry criteria. Intravitreous injection into one eye per patient of pegaptanib (at a dose of 0.3 mg, 1.0 mg, or 3.0 mg) or sham injections were administered every 6 weeks over a period of 48 weeks. The primary end point was the proportion of patients who had lost fewer than 15 letters of visual acuity at 54 weeks. Results: In the combined analysis of the primary end point (for a total of 1186 patients), efficacy was demonstrated, without a dose-response relationship, for all three doses of pegaptanib (P<0.001 for the comparison of 0.3 mg with sham injection; P<0.001 for the comparison of 1.0 mg with sham injection; and P=0.03 for the comparison of 3.0 mg with sham injection). In the group given pegaptanib at 0.3 mg, 70 percent of patients lost fewer than 15 letters of visual acuity, as compared with 55 percent among the controls (P<0.001). The risk of severe loss of visual acuity (loss of 30 letters or more) was reduced from 22 percent in the sham-injection group to 10 percent in the group receiving 0.3 mg of pegaptanib (P<0.001). More patients receiving pegaptanib (0.3 mg), as compared with sham injection, maintained their visual acuity or gained acuity (33 percent vs. 23 percent; P=0.003). As early as six weeks after beginning therapy with the study drug, and at all subsequent points, the mean visual acuity among patients receiving 0.3 mg of pegaptanib was better than in those receiving sham injections (P<0.002). Among the adverse events that occurred, endophthalmitis (in 1.3 percent of patients), traumatic injury to the lens (in 0.7 percent), and retinal detachment (in 0.6 percent) were the most serious and required vigilance. These events were associated with a severe loss of visual acuity in 0.1 percent of patients. Conclusions: Pegaptanib appears to be an effective therapy for neovascular age-related macular degeneration. Its long-term safety is not known. [ABSTRACT FROM AUTHOR]

Purpose: Hyperglycemia is a major risk factor for early lesions of diabetic retinal disease (DRD). Updating the DRD staging system to incorporate relevant basic and cellular mechanisms pertinent to DRD is necessary to better address early disease, disease progression, the use of therapeutic interventions, and treatment effectiveness., Design: We sought to review preclinical and clinical evidence on basic and cellular mechanisms potentially pertinent to DRD that might eventually be relevant to update the DRD staging system., Participants: Not applicable., Methods: The Basic and Cellular Mechanisms Working Group (BCM-WG) of the Mary Tyler Moore Vision Initiative carefully and extensively reviewed available preclinical and clinical evidence through multiple iterations and classified these., Main Outcome Measures: Classification was made into evidence grids, level of supporting evidence, and anticipated future relevance to DRD., Results: A total of 40 identified targets based on pathophysiology and other parameters for DRD were grouped into concepts or evaluated as specific candidates. VEGFA, peroxisome proliferator-activated receptor-alpha related pathways, plasma kallikrein, and angiopoietin 2 had strong agreement as promising for use as biomarkers in diagnostic, monitoring, predictive, prognostic, and pharmacodynamic responses as well as for susceptibility/risk biomarkers that could underlie new assessments and eventually be considered within an updated DRD staging system or treatment, based on the evidence and need for research that would fit within a 2-year timeline. The BCM-WG found there was strong reason also to pursue the following important concepts regarding scientific research of DRD acknowledging their regulation by hyperglycemia: inflammatory/cytokines, oxidative signaling, vasoprotection, neuroprotection, mitophagy, and nutrients/microbiome., Conclusion: Promising targets that might eventually be considered within an updated DRD staging system or treatment were identified. Although the BCM-WG recognizes that at this stage little can be incorporated into a new DRD staging system, numerous potential targets and important concepts deserve continued support and research, as they may eventually serve as biomarkers and/or therapeutic targets with measurable benefits to patients with diabetes., Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article., (© 2024 by the American Academy of Ophthalmology.)

Purpose: VitreoDx is an experimental device enabling push-button collection of a neat vitreous liquid biopsy incidental to an intravitreal injection. We explored the ability of the device to collect a sample usable for proteomic biomarker discovery and testing., Design: Pilot study using ex vivo human eyes., Methods: Non-vitrectomized, human eyes from nine donors 75-91 years of age were refrigerated in BSS and used within 5 days of death. Four VitreoDx devices fitted with 25G needles, and four staked needle insulin syringes with 30G needles, were inserted at equal intervals through the pars plana of each eye and held in place by a fixture. The sampling mode of each VitreoDx device was triggered to attempt to acquire a liquid biopsy up to 70 μL. The plunger of each insulin syringe was retracted to attempt to obtain a liquid biopsy with a maximum volume of 50 μL. Samples acquired with the VitreoDx were extracted to polypropylene cryovials, refrigerated to -80 ºC, and sent for offsite proteomic analysis by proximity extension assay with a focus on panels containing approved and pipelined drug targets for neovascular disease and inflammatory factors., Results: Of the attempted liquid biopsies with the novel 25G VitreoDx, 92% (66 of 72) resulted in successful acquisition (>25 μL) while 89% (64 of 72) attempted by a traditional 30G needle resulted in a successful acquisition. Sample volume sufficient for proteomics array analysis was acquired by the VitreoDx for every eye. Detectable protein was found for 151 of 166 unique proteins assayed in at least 25% of eyes sampled by VitreoDx., Conclusions: The high acquisition rate achieved by the prototype was similar to that achieved in previous clinical studies where a standard syringe was used with a 25G needle to biopsy vitreous fluid directly prior to standard intravitreal injection. Successful aspiration rates were likewise high for 30G needles. Together, these suggest that it is possible to routinely acquire liquid vitreous biopsies from patients who typically receive intravitreal injections with an injection device using a standard size needle without a vitreous cutter. Protein analysis shows that proteins of interest survive the sampling mechanism and may have potential to direct care in the future., Competing Interests: All authors are employees or consultants of Twenty / Twenty Therapeutics, LLC which is developing the VitreoDx device and holds patents for technologies described. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2024 Tumlinson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose of Review: This review provides background on the remaining unmet needs with antivascular endothelial growth factor (VEGF) therapies for the treatment of neovascular age-related macular degeneration (nAMD). We also discuss the developmental story of the Port Delivery System with ranibizumab (PDS; SUSVIMO, Genentech, Inc., South San Francisco, CA, USA)., Recent Findings: Real-world studies have shown that undertreatment is a major reason for continued vision loss in the anti-VEGF era. As a result, there is a need for long-acting anti-VEGF treatment options for patients with nAMD, diabetic macular edema, and other retinal diseases. The PDS is a solid state, refillable, intraocular long-acting drug delivery system that continuously delivers a customized formulation of ranibizumab into the vitreous for 6 months. In a phase 3 trial, the PDS showed equivalent visual acuity improvements with monthly ranibizumab injections in patients with nAMD and adverse events associated with the PDS were well understood and manageable., Summary: The PDS is the first US Food and Drug Administration-approved treatment for nAMD that provides continuous delivery of an anti-VEGF molecule. The PDS offers a unique drug delivery system that has the potential to serve as a platform to be used with other molecules in the future., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: To evaluate the safety and efficacy of the Port Delivery System with ranibizumab (PDS) for the treatment of neovascular age-related macular degeneration (nAMD)., Design: Phase 3, open-label, randomized, visual acuity assessor-masked noninferiority and equivalence trial., Participants: Patients with nAMD diagnosed within 9 months of screening previously treated with and responsive to anti-vascular endothelial growth factor therapy., Methods: Patients were randomized 3:2 to treatment with the PDS with ranibizumab 100 mg/ml with fixed 24-week (Q24W) refill-exchanges (PDS Q24W) or intravitreal ranibizumab 0.5-mg injections every 4 weeks (monthly ranibizumab)., Main Outcome Measures: Primary end point was change in best-corrected visual acuity (BCVA) Early Treatment Diabetic Retinopathy Study letter (letters) score from baseline averaged over weeks 36 and 40 (noninferiority margin,-4.5 letters; equivalence margin, ±4.5 letters)., Results: Archway enrolled 418 patients; 251 were randomized to and 248 received treatment with the PDS Q24W, and 167 were randomized to and received treatment with monthly ranibizumab. Baseline BCVA was 74.4 letters (PDS Q24W arm) and 75.5 letters (monthly ranibizumab arm; Snellen equivalent, 20/32). Adjusted mean change in BCVA score from baseline averaged over weeks 36 and 40 was +0.2 letters (standard error [SE], 0.5 letters) in the PDS Q24W arm and +0.5 letters (SE, 0.6 letters) in the monthly ranibizumab arm (difference, -0.3 letters; 95% confidence interval, -1.7 to 1.1 letters). PDS Q24W was both noninferior and equivalent to monthly ranibizumab. Of 246 PDS-treated patients assessed for supplemental ranibizumab treatment, 242 (98.4%) did not receive supplemental ranibizumab treatment before the first refill-exchange procedure, including 4 patients who discontinued treatment before the first refill-exchange procedure. Prespecified ocular adverse events of special interest were reported in 47 patients (19.0%) in the PDS Q24W arm and 10 patients (6.0%) in the monthly ranibizumab arm, which included, in the former arm, 4 (1.6%) endophthalmitis cases, 2 (0.8%) retinal detachments, 13 (5.2%) vitreous hemorrhages, 6 (2.4%) conjunctival erosions, and 5 (2.0%) conjunctival retractions. Most ocular adverse events in the PDS Q24W arm occurred within 1 month of implantation., Conclusions: Archway met its primary objective and PDS Q24W demonstrated noninferior and equivalent efficacy to monthly ranibizumab, with 98.4% of PDS-treated patients not receiving supplemental treatment in the first 24-week interval., (Copyright © 2021 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Background: To reduce treatment burden and optimise patient outcomes in diabetic macular oedema, we present 1-year results from two phase 3 trials of faricimab, a novel angiopoietin-2 and vascular endothelial growth factor-A bispecific antibody., Methods: YOSEMITE and RHINE were randomised, double-masked, non-inferiority trials across 353 sites worldwide. Adults with vision loss due to centre-involving diabetic macular oedema were randomly assigned (1:1:1) to intravitreal faricimab 6·0 mg every 8 weeks, faricimab 6·0 mg per personalised treatment interval (PTI), or aflibercept 2·0 mg every 8 weeks up to week 100. PTI dosing intervals were extended, maintained, or reduced (every 4 weeks up to every 16 weeks) based on disease activity at active dosing visits. The primary endpoint was mean change in best-corrected visual acuity at 1 year, averaged over weeks 48, 52, and 56. Efficacy analyses included the intention-to-treat population (non-inferiority margin 4 Early Treatment Diabetic Retinopathy Study [ETDRS] letters); safety analyses included patients with at least one dose of study treatment. These trials are registered with ClinicalTrials.gov (YOSEMITE NCT03622580 and RHINE NCT03622593)., Findings: 3247 patients were screened for eligibility in YOSEMITE (n=1532) and RHINE (n=1715). After exclusions, 940 patients were enrolled into YOSEMITE between Sept 5, 2018, and Sept 19, 2019, and 951 patients were enrolled into RHINE between Oct 9, 2018, and Sept 20, 2019. These 1891 patients were randomly assigned to faricimab every 8 weeks (YOSEMITE n=315, RHINE n=317), faricimab PTI (n=313, n=319), or aflibercept every 8 weeks (n=312, n=315). Non-inferiority for the primary endpoint was achieved with faricimab every 8 weeks (adjusted mean vs aflibercept every 8 weeks in YOSEMITE 10·7 ETDRS letters [97·52% CI 9·4 to 12·0] vs 10·9 ETDRS letters [9·6 to 12·2], difference -0·2 ETDRS letters [-2·0 to 1·6]; RHINE 11·8 ETDRS letters [10·6 to 13·0] vs 10·3 ETDRS letters [9·1 to 11·4] letters, difference 1·5 ETDRS letters [-0·1 to 3·2]) and faricimab PTI (YOSEMITE 11·6 ETDRS letters [10·3 to 12·9], difference 0·7 ETDRS letters [-1·1 to 2·5]; RHINE 10·8 ETDRS letters [9·6 to 11·9], difference 0·5 ETDRS letters [-1·1 to 2·1]). Incidence of ocular adverse events was comparable between faricimab every 8 weeks (YOSEMITE n=98 [31%], RHINE n=137 [43%]), faricimab PTI (n=106 [34%], n=119 [37%]), and aflibercept every 8 weeks (n=102 [33%], n=113 [36%])., Interpretation: Robust vision gains and anatomical improvements with faricimab were achieved with adjustable dosing up to every 16 weeks, demonstrating the potential for faricimab to extend the durability of treatment for patients with diabetic macular oedema., Funding: F Hoffmann-La Roche., Competing Interests: Declaration of interests CCW reports research support from Adverum, Aerie, Aldeyra, Alimera, Allergan, Amgen, Apellis, AsclepiX, Bayer, Boehringer Ingelheim, Chengdu Kanghong, Clearside, Gemini, Genentech, Graybug Vision, Gyroscope, Ionis, iRenix Medical, Iveric Bio, Kodiak, Lowy Medical Research Institute, Neurotech, NGM Bio, Novartis, Oxurion, RecensMedical, Regeneron, Regenxbio, Roche, SamChunDang Pharm, Samsung Bioepis, Taiwan Liposome Company, and Xbrane BioPharma, outside the submitted work. CCW reports consulting fees from Adverum, Aerie, Aerpio, Allergan, Allgenesis, Apellis, Arrowhead, Bausch and Lomb, Bayer, Bionic Vision Technologies, Chengdu Kanghong, Clearside, EyePoint, Genentech, Gyroscope, Iveric Bio, Janssen, Kato, Kodiak, Long Bridge Medical, NGM Bio, Novartis, OccuRx, Ocular Therapeutix, ONL Therapeutics, Opthea, Oxurion, Palatin, PolyPhotonix, RecensMedical, Regeneron, Regenxbio, Roche, Santen, Surrozen, Takeda, Verana Health, and Vitranu, outside the submitted work. CCW reports other personal fees from Regeneron, stock or stock options from ONL Therapeutics, PolyPhotonix, RecensMedical, and Visgenx, and has served on advisory boards for Kato, outside the submitted work. CCW has served as a board member of the American Society of Retina Specialists and the Vit-Buckle Society, outside the submitted work. FA is an employee of Genentech. APA was an employee of Genentech during the course of this study and reports stock or stock options from Roche. KB was an employee of Genentech during the course of this study and is a current employee of Roche Products (Ireland). DAE reports research support from Alkahest, AsclepiX, Bayer, Chengdu Kanghong, EyePoint, Gemini, Genentech, Gyroscope, Ionis, Iveric Bio, Kodiak, Mylan, NGM Bio, Novartis, Ocular Therapeutix, Opthea, RecensMedical, Regeneron, and Regenxbio, outside the submitted work. DAE reports consulting fees from Alimera, Allergan, Apellis, Bausch and Lomb, Dutch Ophthalmic, EyePoint, Genentech, Gyroscope, Iveric Bio, KKR, Kodiak, Notal Vision, Novartis, RecensMedical, Regeneron, and Regenxbio, outside the submitted work. DAE reports other personal fees from Allergan, Apellis, Bayer, Dutch Ophthalmic, EyePoint, Genentech, and Novartis; stock or stock options from Boston Image Reading Center, Clearside, Hemera, and Network Eye; and has served on advisory boards for Genentech, Iveric Bio, and RecensMedical, outside the submitted work. DAE has served as a board member of the Florida Society of Ophthalmology, outside the submitted work. ZH is an employee of Genentech, and reports stock or stock options from Genentech. HL is an employee of Genentech, reports personal fees and stock or stock options from Roche/Genentech, and is a coauthor on patent application WO202123804 involving the PTI algorithm. AL reports research support from Notal Vision and Novartis, and consulting fees from Allergan, Bayer, Beyeonics Surgical, and Syneos Health, outside the submitted work. SM is an employee of Genentech, and reports stock or stock options from Genentech. IAP reports consulting and other personal fees from Allergan, Bayer, Novartis, and Roche, and has served on advisory boards for Bayer, Novartis, and Roche, outside the submitted work. TS reports research support from Bayer, Chugai, Novartis, Santen, and Senju; consulting and other personal fees from Bayer, Novartis, and Senju; and has served on advisory boards for Bayer, Novartis, and Roche, outside the submitted work. PGS reports personal fees and has served on advisory boards for Roche, outside the submitted work. DS is an employee of Roche Products, reports personal fees and stock or stock options from Roche, and is a coauthor on patent application WO202123804 involving the PTI algorithm. JKS reports research support from Boehringer Ingelheim, Jaeb Center for Health Research, Juvenile Diabetes Research Foundation, KalVista, Novartis, Optovue, and Physical Sciences; personal fees from Merck, Novartis, and Novo Nordisk; and equipment loans from Adaptive Sensory Technology, Boston Micromachines, and Optovue, outside the submitted work. JAW reports research support from Adverum, Alimera, Bayer, Clover Therapeutics, Genentech, Iveric Bio, Kodiak, Lowy Medical Research Institute, NIH National Eye Institute, Neurotech, Opthea, and Regeneron, and consulting fees from Genentech, outside the submitted work. JRW is an employee of Genentech, reports stock or stock options from Genentech, and is a coauthor on patent application WO202123804 involving the PTI algorithm. RT reports consulting and personal fees and has served on advisory boards for AbbVie, Alcon, Allergan, Apellis, Bayer, Chengdu Kanghong, Genentech, Iveric Bio, Novartis, Oculis, Roche, and Thea, and reports equipment from Zeiss, outside the submitted work., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

This article aims to identify key opportunities for improvement in the diagnosis and treatment of retinal disease, and describe recent innovations that will potentially facilitate improved outcomes with existing intravitreal vascular endothelial growth factor (VEGF) therapies and lay the groundwork for new treatment approaches. The review begins with a summary of the key discoveries that led to the development of anti-VEGF therapies and briefly reviews their impact on clinical practice. Opportunities for improvements in diagnosis, real-world outcomes with existing therapies, long-acting therapeutics and personalised health care are discussed, as well as the need to identify new targets for therapeutic intervention. Low-cost, remote patient screening and monitoring using artificial intelligence (AI)-based technologies can help improve diagnosis rates and enable remote disease monitoring with minimal patient burden. AI-based tools can be applied to generate patient-level prognostic data and predict individual treatment needs, reducing the time needed to optimise a patient's treatment regimen. Long-acting therapeutics can help improve visual outcomes by reducing the treatment burden. When paired with AI-generated prognoses, long-acting therapeutics enable the possibility of vision loss prevention. Dual-acting drugs may help improve efficacy and/or durability beyond what is possible with anti-VEGF agents alone. Recent developments and ongoing innovations will help build upon the success of anti-VEGF therapies to further reduce vision loss owing to retinal disease while lowering the overall burden of care.

Purpose: To evaluate the safety and efficacy of the Port Delivery System with ranibizumab (PDS) for neovascular age-related macular degeneration (nAMD) treatment., Design: Phase 2, multicenter, randomized, active treatment-controlled clinical trial., Participants: Patients diagnosed with nAMD within 9 months who had received 2 or more prior anti-vascular endothelial growth factor intravitreal injections and were responsive to treatment., Methods: Patients were randomized 3:3:3:2 to receive the PDS filled with ranibizumab 10 mg/ml, 40 mg/ml, 100 mg/ml, or monthly intravitreal ranibizumab 0.5-mg injections., Main Outcome Measures: Time to first implant refill assessed when the last enrolled patient completed the month 9 visit (primary efficacy end point), improvement in best-corrected visual acuity (BCVA) and central foveal thickness (CFT), and safety., Results: The primary analysis population was 220 patients, with 58, 62, 59, and 41 patients in the PDS 10-mg/ml, PDS 40-mg/ml, PDS 100-mg/ml, and monthly intravitreal ranibizumab 0.5-mg arms, respectively. Median time to first implant refill was 8.7, 13.0, and 15.0 months in the PDS 10-mg/ml, PDS 40-mg/ml, and PDS 100-mg/ml arms, respectively. At month 9, the adjusted mean BCVA change from baseline was ‒3.2 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, ‒0.5 ETDRS letters, +5.0 ETDRS letters, and +3.9 ETDRS letters in the PDS 10-mg/ml, PDS 40-mg/ml, PDS 100-mg/ml, and monthly intravitreal ranibizumab 0.5-mg arms, respectively. At month 9, the adjusted mean CFT change from baseline was similar in the PDS 100-mg/ml and monthly intravitreal ranibizumab 0.5-mg arms. The optimized PDS implant insertion and refill procedures were generally well tolerated. After surgical procedure optimization, postoperative vitreous hemorrhage rate was 4.5% (7/157; 1 event classified as serious). There was no evidence of implant clogging., Conclusions: In the phase 2 Ladder trial, the PDS was generally well tolerated and demonstrated a dose response across multiple end points in patients with nAMD. The PDS 100-mg/ml arm showed visual and anatomic outcomes comparable with monthly intravitreal ranibizumab 0.5-mg injections but with a reduced total number of ranibizumab treatments. The PDS has the potential to reduce treatment burden in nAMD while maintaining vision., (Copyright © 2019 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: To develop deep learning (DL) models for the automatic detection of optical coherence tomography (OCT) measures of diabetic macular thickening (MT) from color fundus photographs (CFPs)., Methods: Retrospective analysis on 17,997 CFPs and their associated OCT measurements from the phase 3 RIDE/RISE diabetic macular edema (DME) studies. DL with transfer-learning cascade was applied on CFPs to predict time-domain OCT (TD-OCT)-equivalent measures of MT, including central subfield thickness (CST) and central foveal thickness (CFT). MT was defined by using two OCT cutoff points: 250 μm and 400 μm. A DL regression model was developed to directly quantify the actual CFT and CST from CFPs., Results: The best DL model was able to predict CST ≥ 250 μm and CFT ≥ 250 μm with an area under the curve (AUC) of 0.97 (95% confidence interval [CI], 0.89-1.00) and 0.91 (95% CI, 0.76-0.99), respectively. To predict CST ≥ 400 μm and CFT ≥ 400 μm, the best DL model had an AUC of 0.94 (95% CI, 0.82-1.00) and 0.96 (95% CI, 0.88-1.00), respectively. The best deep convolutional neural network regression model to quantify CST and CFT had an R2 of 0.74 (95% CI, 0.49-0.91) and 0.54 (95% CI, 0.20-0.87), respectively. The performance of the DL models declined when the CFPs were of poor quality or contained laser scars., Conclusions: DL is capable of predicting key quantitative TD-OCT measurements related to MT from CFPs. The DL models presented here could enhance the efficiency of DME diagnosis in tele-ophthalmology programs, promoting better visual outcomes. Future research is needed to validate DL algorithms for MT in the real-world.

The targeting of vascular endothelial growth factor A (VEGFA), a crucial regulator of both normal and pathological angiogenesis, has revealed innovative therapeutic approaches in oncology and ophthalmology. The first VEGFA inhibitor, bevacizumab, was approved by the US Food and Drug Administration in 2004 for the first-line treatment of metastatic colorectal cancer, and the first VEGFA inhibitors in ophthalmology, pegaptanib and ranibizumab, were approved in 2004 and 2006, respectively. To mark this tenth anniversary of anti-VEGFA therapy, we discuss the discovery of VEGFA, the successes and challenges in the development of VEGFA inhibitors and the impact of these agents on the treatment of cancers and ophthalmic diseases.

Systematic study of the mechanisms underlying pathological ocular neovascularization has yielded a wealth of knowledge about pro- and anti-angiogenic factors that modulate diseases such as neovascular age-related macular degeneration. The evidence implicating vascular endothelial growth factor (VEGF) in particular has led to the development of a number of approved anti-VEGF therapies. Additional proangiogenic targets that have emerged as potential mediators of ocular neovascularization include hypoxia-inducible factor-1, angiopoietin-2, platelet-derived growth factor-B and components of the alternative complement pathway. As for VEGF, knowledge of these factors has led to a product pipeline of many more novel agents that are in various stages of clinical development in the setting of ocular neovascularization. These agents are represented by a range of drug classes and, in addition to novel small- and large-molecule VEGF inhibitors, include gene therapies, small interfering RNA agents and tyrosine kinase inhibitors. In addition, combination therapy is beginning to emerge as a strategy to improve the efficacy of individual therapies. Thus, a variety of agents, whether administered alone or as adjunctive therapy with agents targeting VEGF, offer the promise of expanding the range of treatments for ocular neovascular diseases., (© 2016 S. Karger AG, Basel.)

Purpose: Characterization of a mouse model of spontaneous choroidal neovascularization (sCNV) and its effect on retinal architecture and function., Methods: The sCNV mouse phenotype was characterized by using fundus photography, fluorescein angiography, confocal scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), ERG, immunostaining, biochemistry, and electron microscopy. A role for VEGF-A signaling in sCNV was investigated by using neutralizing antibodies and a role for macrophages explored by cell-depletion studies., Results: The sCNV starts between postnatal day 10 and 15 (P10-P15), increasing in number and severity causing RPE disruption and dysfunction. Various morphological methods confirmed the choroidal origin and subretinal position of the angiogenic vessels. At approximately P25, vessels were present in the outer retina with instances of anastomosis of some sCNV lesions with the retinal vasculature. The number of CNV lesions was significantly decreased by systemic blockade of the VEGF-A pathway. Choroidal neovascularization size also was significantly modulated by reducing the number of lesion-associated macrophages. Later stages of sCNV were associated with edema, neuronal loss, and dysfunction., Conclusions: The sCNV mouse is a new model for the study of both early and late events associated with choroidal neovascularization. Pharmacological reduction in sCNV with VEGF-A antagonists and an anti-inflammatory strategy suggests the model may be useful for investigating novel targets for treating human ocular neovascular disease., (Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.)

Purpose: To report 36-month outcomes of RIDE (NCT00473382) and RISE (NCT00473330), trials of ranibizumab in diabetic macular edema (DME)., Design: Phase III, randomized, multicenter, double-masked, 3-year trials, sham injection-controlled for 2 years., Participants: Adults with DME (n=759), baseline best-corrected visual acuity (BCVA) 20/40 to 20/320 Snellen equivalent, and central foveal thickness (CFT) ≥ 275 μm on optical coherence tomography., Methods: Patients were randomized equally (1 eye per patient) to monthly 0.5 mg or 0.3 mg ranibizumab or sham injection. In the third year, sham patients, while still masked, were eligible to cross over to monthly 0.5 mg ranibizumab. Macular laser was available to all patients starting at month 3; panretinal laser was available as necessary., Main Outcome Measures: The proportion of patients gaining ≥15 Early Treatment Diabetic Retinopathy Study letters in BCVA from baseline at month 24., Results: Visual acuity (VA) outcomes seen at month 24 in ranibizumab groups were consistent through month 36; the proportions of patients who gained ≥15 letters from baseline at month 36 in the sham/0.5 mg, 0.3 mg, and 0.5 mg ranibizumab groups were 19.2%, 36.8%, and 40.2%, respectively, in RIDE and 22.0%, 51.2%, and 41.6%, respectively, in RISE. In the ranibizumab arms, reductions in CFT seen at 24 months were, on average, sustained through month 36. After crossover to 1 year of treatment with ranibizumab, average VA gains in the sham/0.5 mg group were lower compared with gains seen in the ranibizumab patients after 1 year of treatment (2.8 vs. 10.6 and 11.1 letters). Per-injection rates of endophthalmitis remained low over time (∼0.06% per injection). The incidence of serious adverse events potentially related to systemic vascular endothelial growth factor inhibition was 19.7% in patients who received 0.5 mg ranibizumab compared with 16.8% in the 0.3 mg group., Conclusions: The strong VA gains and improvement in retinal anatomy achieved with ranibizumab at month 24 were sustained through month 36. Delayed treatment in patients receiving sham treatment did not seem to result in the same extent of VA improvement observed in patients originally randomized to ranibizumab. Ocular and systemic safety was generally consistent with the results seen at month 24., Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references., (Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: Assess 12-month efficacy and safety of intraocular injections of 0.3 mg or 0.5 mg ranibizumab in patients with macular edema after branch retinal vein occlusion (BRVO)., Design: Prospective, randomized, sham injection-controlled, double-masked, multicenter trial., Participants: A total of 397 patients with macular edema after BRVO., Methods: Eligible patients were randomized 1:1:1 to 6 monthly injections of 0.3 mg or 0.5 mg ranibizumab or sham injections. After 6 months, all patients with study eye best-corrected visual acuity (BCVA) ≤20/40 or central subfield thickness ≥250 μm were to receive ranibizumab. Patients could receive rescue laser treatment once during the treatment period and once during the observation period if criteria were met., Main Outcome Measures: The main efficacy outcome reported is mean change from baseline BCVA letter score at month 12. Additional visual and anatomic parameters were assessed., Results: Mean (95% confidence interval) change from baseline BCVA letter score at month 12 was 16.4 (14.5-18.4) and 18.3 (15.8-20.9) in the 0.3 mg and 0.5 mg groups, respectively, and 12.1 (9.6-14.6) in the sham/0.5 mg group (P<0.01, each ranibizumab group vs. sham/0.5 mg). The percentage of patients who gained ≥15 letters from baseline BCVA at month 12 was 56.0% and 60.3% in the 0.3 mg and 0.5 mg groups, respectively, and 43.9% in the sham/0.5 mg group. On average, there was a marked reduction in central foveal thickness (CFT) after the first as-needed injection of 0.5 mg ranibizumab in the sham/0.5 mg group, which was sustained through month 12. No new ocular or nonocular safety events were identified., Conclusions: At month 12, treatment with ranibizumab as needed during months 6-11 maintained, on average, the benefits achieved by 6 monthly ranibizumab injections in patients with macular edema after BRVO, with low rates of ocular and nonocular safety events. In the sham/0.5 mg group, treatment with ranibizumab as needed for 6 months resulted in rapid reduction in CFT to a similar level as that in the 0.3 mg ranibizumab treatment group and an improvement in BCVA, but not to the extent of that in the 2 ranibizumab groups. Intraocular injections of ranibizumab provide an effective treatment for macular edema after BRVO., Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references., (Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: To explore the role of integrin alpha5beta1 in proliferative vitreoretinopathy (PVR) pathogenesis by evaluating the expression alpha5beta1 on ARPE-19 cells and patient proliferative membranes, quantifying the inhibitory effects of JSM6427 (a small molecule alpha5beta1 inhibitor) on ARPE-19 cell adhesion and migration, and assessing the therapeutic potential of JSM6427 in a rabbit retinal detachment model., Methods: Expression of alpha5beta1 was evaluated on activated ARPE-19 cells by flow cytometry and on PVR membranes by immunohistochemistry. ARPE-19 cells were used in fibronectin-dependent adhesion and migration assays with various concentrations of JSM6427; IC(50) was calculated. In the rabbit model, eyes were intravitreally injected with vehicle or JSM6427 on day 0 or 1 after retinal detachment; BrdU was administered intravitreally on day 3, and retinal tissues were harvested on day 3 (4 hours later) or 7. Retinal scarring, cellular proliferation, and inflammatory responses were quantified, and retinal morphology was analyzed in retinal sections., Results: Activated ARPE-19 cells and PVR membranes expressed high levels of alpha5beta1; expression was low in control eyes. JSM6427 provided a dose-dependent blockade of ARPE-19 cell adhesion to fibronectin (IC(50), 7.1 +/- 2.5 microM) and inhibition of migration (IC(50), 6.0 +/- 4.5 microM). In the rabbit model, intravitreal injection of JSM6427 provided significant inhibition of proliferation of retinal cells (Müller cells, microglia, and macrophages) on days 3 and 7 after detachment and inhibition of inflammatory response and retinal scarring on day 7 after detachment., Conclusions: JSM6427 is a promising treatment for PVR, with data suggesting that inhibition of alpha5beta1-fibronectin interactions addresses multiple pathways involving retinal pigment epithelial, glial, and inflammatory cells.

The complement cascade has been identified as a key factor in the pathogenesis of age-related macular degeneration (AMD). As a result, pharmacological modulation of the complement cascade is being investigated as a therapeutic strategy for AMD. The genetic data point to a triggering of the complement cascade, which subsequently cannot be damped down. Despite promising genetic, preclinical and immunolabeling data, important questions remain to be answered regarding the role of complement in the pathogenesis of AMD. The involvement of the complement cascade in the vision threatening stages of AMD, e.g. geographic atrophy and choroidal neovascularization, remain unknown. Additionally, the optimal component(s) of the complement cascade to be targeted for modulation still need to be identified. Answering these and other questions will provide investigators with a clear framework with which to evaluate progress in the field and help guide the development of future clinical therapeutics.

Objective: To evaluate the pharmacologic activity and tolerability of JSM6427, a potent and first selective small-molecule inhibitor of integrin alpha5beta1, in monkey and rabbit models of choroidal neovascularization (CNV)., Methods: JSM6427 selectivity for alpha5beta1 was evaluated by in vitro binding assays while the ability of JSM6427 to inhibit CNV was investigated in a laser-induced monkey model and a growth factor-induced rabbit model. Intravitreal injections of JSM6427 (100, 300, or 1000 microg) or vehicle were administered immediately after the CNV induction procedure and at weekly intervals for 4 weeks. Fluorescein angiography was performed weekly. Ocular tolerability was evaluated ophthalmoscopically and histologically in both models; additional assessments in monkeys included electroretinography, biomicroscopy, pathological examination, and analysis of JSM6427 pharmacokinetics., Results: JSM6427 was highly selective for the alpha5beta1-fibronectin interaction. Weekly intravitreal injections of JSM6427 resulted in a statistically significant dose-dependent inhibition of CNV in laser-induced and growth factor-induced models without any ocular JSM6427-related adverse effects. JSM6427 was cleared through the systemic circulation with no evidence of systemic accumulation., Conclusions: Intravitreal JSM6427 provided dose-dependent inhibition of CNV in monkey and rabbit experimental models., Clinical Relevance: JSM6427 may provide a new approach for the treatment of ocular neovascular diseases such as age-related macular degeneration in humans.

The strategies for improving control of age-related macular degeneration with combination therapies are evolving. The focus on more effective blockade of choroidal neovascularization has shifted to include control of additional processes implicated in disease progression, such as neural death, inflammation, or fibrosis. Although there is likely to be a strong interrelationship between choroidal neovascularization and inflammation that contributes to advanced stages of disease progression, including fibrosis, combining treatment strategies may enlarge the opportunity to prevent both early and late vision loss.

Objectives: To assess the safety and efficacy of intravitreous pegaptanib sodium for the treatment of macular edema following central retinal vein occlusion (CRVO)., Design: This dose-ranging, double-masked, multicenter, phase 2 trial included subjects with CRVO for 6 months' or less duration randomly assigned (1:1:1) to receive pegaptanib sodium or sham injections every 6 weeks for 24 weeks (0.3 mg and 1 mg, n=33; sham, n=32)., Main Outcome Measure: Visual acuity at week 30., Results: In the primary analysis at week 30, 12 of 33 (36%) subjects treated with 0.3 mg of pegaptanib sodium and 13 of 33 (39%) treated with 1 mg gained 15 or more letters from baseline vs 9 of 32 (28%) sham-treated subjects (P= .48 for 0.3 mg and P= .35 for 1 mg of pegaptanib sodium vs sham). In secondary analyses, subjects treated with pegaptanib sodium were less likely to lose 15 or more letters (9% and 6%; 0.3-mg and 1-mg pegaptanib sodium groups, respectively) compared with sham-treated eyes (31%; P= .03 for 0.3 mg and P= .01 for 1 mg of pegaptanib sodium vs sham) and showed greater improvement in mean visual acuity (+7.1 and +9.9, respectively, vs -3.2 letters with sham; P= .09 for 0.3 mg and P= .02 for 1 mg of pegaptanib sodium vs sham). By week 1, the mean central retinal thickness decreased in the 0.3-mg and 1-mg pegaptanib sodium groups by 269 microm and 210 microm, respectively, vs 5 microm with sham (P< .001)., Conclusions: Based on this 30-week study, intravitreous pegaptanib sodium appears to provide visual and anatomical benefits in the treatment of macular edema following CRVO., Application to Clinical Practice: Benefits accrued with intravitreous pegaptanib sodium treatment of macular edema following CRVO suggest a role for vascular endothelial growth factor in the pathogenesis of this condition., Trial Registration: clinicaltrials.gov Identifier: NCT00088283.

Aims: To evaluate the safety of up to 3 years of pegaptanib sodium therapy in the treatment of neovascular age-related macular degeneration (NV-AMD)., Methods: Two concurrent, prospective, multicentre, double-masked studies randomised subjects with all angiographic lesion compositions of NV-AMD to receive intravitreous pegaptanib sodium (0.3, 1 and 3 mg) or sham injections every 6 weeks for 54 weeks. Those initially assigned to pegaptanib were rerandomised to continue or discontinue therapy for 48 more weeks; sham-treated subjects continued sham, discontinued or received pegaptanib. At 102 weeks, subjects receiving pegaptanib 0.3 mg or 1 mg in years 1 or 2 continued; those receiving pegaptanib 3 mg or who did not receive treatment in years 1 and 2 were rerandomised to 0.3 mg or 1 mg for year 3., Results: As in years 1 and 2, pegaptanib was well tolerated in year 3. Adverse events were mainly ocular in nature, mild, transient and injection-related. Serious adverse events were rare. No evidence of systemic safety signals attributed to vascular endothelial growth factor inhibition arose in year 3. There were no findings in relation to vital signs or electrocardiogram results suggesting a relationship to pegaptanib treatment., Conclusion: The 3-year safety profile of pegaptanib sodium was favourable in patients with NV-AMD.

Objective: To compare the cost-effectiveness of pegaptanib and usual care within three distinct cohorts of subfoveal neovascular age-related macular degeneration (NV-AMD) patients, that is, those with early, moderate, and late disease, using a comprehensive economic model., Methods: A Markov framework was used to model lifetime movement of a subfoveal NV-AMD cohort through health states based on visual acuity. The model takes a US payer perspective of patients over the age of 65 years. Clinical efficacy was based on published results for the 0.3 mg pegaptanib and usual care groups. Expert interviews were conducted to determine adverse event treatment patterns and vision rehabilitation resource use. Incidence and costs of comorbidities such as depression and fractures associated with the effects of declining visual acuity were based on our previously published analysis of Medicare data. Transition probabilities were derived from published clinical trial data for each 3-month cycle. Utilities were derived from published sources. Three runs of the model were conducted with cohorts of newly diagnosed patients. Patients were classified as having early, moderate, or late NV-AMD defined as visual acuity in the better-seeing eye of 20/40 to more than 20/80, 20/80 to more than 20/200, and 20/200 to more than 20/400, respectively. Costs and outcomes were discounted 3.0% per annum., Results: Incremental costs per vision-year gained and per quality-adjusted life-year (QALY) gained for early NV-AMD patients were approximately one-third those of patients with late disease ($15,279 vs. $57,230 and $36,282 vs. $132,381, respectively). On average, patients treated early with either pegaptanib or usual care incurred lower lifetime total direct costs than those treated later. Sensitivity analysis showed that base-case incremental costs per QALY gained for pegaptanib versus usual care were relatively robust., Conclusions: For patients with subfoveal NV-AMD, treatment with pegaptanib should be started as early as possible to maximize the clinical and economic benefits.

There is an accumulating body of evidence that immunological mechanisms play a prominent role in the pathogenesis of diabetic retinopathy (DR), which is characterized by many features typical of inflammation. The upregulation of cytokines and other inflammatory mediators leading to persistent low-grade inflammation and an influx of leukocytes, is believed to contribute actively to DR-associated damage to the retinal vasculature and retinal neovascularization. This review will describe preclinical and clinical studies that document an inflammatory basis for DR and that support the use of nonsteroidal anti-inflammatory drugs, corticosteroids, and anti-vascular endothelial growth factor agents in its treatment. In addition, emerging therapeutic approaches based on ongoing investigations will be discussed, including those involving blockade of angiotensin receptors and other molecular targets such as tumor necrosis factor-alpha.

Purpose: To investigate the effect of the combined treatment of photodynamic therapy and specific VEGF165 inhibition with pegaptanib sodium (Macugen; Eyetech Pharmaceuticals, Lexington, MA) on ocular neovascularization., Methods: Photodynamic therapy's (PDT's) effects on the integrity of pegaptanib sodium were analyzed by HPLC, a VEGF165-binding assay, and a VEGF165-induced tissue factor gene expression assay. The effects of mono- or combined treatment on vessel growth and regression were determined in a murine corneal neovascularization model. The effects of combined treatment on vessel growth were also determined in a murine choroidal neovascularization model., Results: PDT did not affect the chemical composition of pegaptanib sodium nor the efficacy of pegaptanib sodium in the inhibition of VEGF165 binding to Flt-1 and VEGF165-induced gene expression. In an animal model of effects on existing ocular neovascular lesions (corneal neovascularization), PDT monotherapy yielded an initial regression of these vessels, but there followed a rapid regrowth. In contrast, pegaptanib sodium monotherapy yielded little regression but potently abrogated further vessel growth. The combination of pegaptanib sodium and PDT resulted in the regression of the neovascular lesions, as observed with PDT alone, but also prevented significant vessel regrowth, leading to a significantly greater reduction in lesion size than did each monotherapy. In addition, there was a significantly greater effect of the combination of pegaptanib sodium and PDT on lesion size in choroidal neovascularization than with each monotherapy. Pretreatment with pegaptanib sodium appeared to decrease the efficacy of PDT-induced vessel regression in corneal neovascularization, and as such the enhanced efficacy over monotherapy when the agents were delivered simultaneously was not observed., Conclusions: Although the combined simultaneous treatment of ocular neovascularization with PDT and pegaptanib sodium may provide a more effective approach for the regression and overall treatment of CNV associated with AMD, the order of addition of these treatments may play a role in achieving optimal efficacy.

Objective: To characterize the safety, tolerability, and pharmacokinetics of the pegylated anti-vascular endothelial growth factor (VEGF) aptamer pegaptanib sodium in subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD)., Design: Prospective 2-cohort study: (1) open-label cohort and (2) randomized, double-masked, uncontrolled multicenter trial., Participants: In the combined cohorts, 147 subjects with any angiographic subtype of subfoveal choroidal neovascularization secondary to AMD and best-corrected visual acuities (VAs) in the study eye of 20/40 to 20/320 and in the fellow eye of 20/800 or better received pegaptanib sodium., Intervention: Subjects were randomized to receive intravitreous pegaptanib sodium (1 mg or 3 mg [3- and 10-fold higher than the 0.3-mg approved dose]) every 6 weeks for 54 weeks., Main Outcome Measures: Safety assessments included blood chemistries, urinalyses, vital signs, electrocardiograms, serum antipegaptanib antibody assays, adverse events, VAs, and intraocular pressures. After the first, fourth, and eighth injections, serial blood samples were obtained for quantification of pegaptanib plasma concentrations., Results: No antipegaptanib immunoglobulin G (IgG) or IgM antibodies were detected. Few systemic adverse events were noted. Mild or moderate ocular adverse events related to the injection procedure were reported in most patients. Pegaptanib did not accumulate in plasma after multiple doses; systemic exposures were similar after the first, fourth, and eighth doses. The mean apparent terminal half-life was 10 days. Evaluation of blood pressure (BP) and urine protein, both of which are known to be affected by systemic VEGF inhibition, indicated no evidence of a pegaptanib treatment effect on these parameters. Mean BP at the end of year 1 remained below 140 mmHg (systolic) and 90 mmHg (diastolic), levels considered hypertension by the American College of Cardiology., Conclusions: At doses up to 10-fold higher than the 0.3-mg dose approved for the treatment of AMD, pegaptanib sodium was well tolerated, with no detectable clinical evidence of systemic VEGF inhibition (i.e., no clinically meaningful changes in proteinuria or mean BP) and no clinically relevant ocular inflammation. Most ocular adverse events were related to the injection procedure itself and were mild or moderate in severity.

Vascular endothelial growth factor-A (VEGF-A) has recently been recognized as an important neuroprotectant in the central nervous system. Given its position as an anti-angiogenic target in the treatment of human diseases, understanding the extent of VEGF's role in neural cell survival is paramount. Here, we used a model of ischemia-reperfusion injury and found that VEGF-A exposure resulted in a dose-dependent reduction in retinal neuron apoptosis. Although mechanistic studies suggested that VEGF-A-induced volumetric blood flow to the retina may be partially responsible for the neuroprotection, ex vivo retinal culture demonstrated a direct neuroprotective effect for VEGF-A. VEGF receptor-2 (VEGFR2) expression was detected in several neuronal cell layers of the retina, and functional analyses showed that VEGFR2 was involved in retinal neuroprotection. VEGF-A was also shown to be involved in the adaptive response to retinal ischemia. Ischemic preconditioning 24 hours before ischemia-reperfusion injury increased VEGF-A levels and substantially decreased the number of apoptotic retinal cells. The protective effect of ischemic preconditioning was reversed after VEGF-A inhibition. Finally, chronic inhibition of VEGF-A function in normal adult animals led to a significant loss of retinal ganglion cells yet had no observable effect on several vascular parameters. These findings have implications for both neural pathologies and ocular vascular diseases, such as diabetic retinopathy and age-related macular degeneration.

Purpose: Retinal ganglion cell (RGC) loss occurs in response to increased intraocular pressure (IOP) and/or retinal ischemia in glaucoma and leads to impairment of vision. This study was undertaken to test the efficacy of erythropoietin (EPO) in providing neuroprotection to RGCs in vivo., Methods: The neuroprotective effects of EPO were studied in the DBA/2J mouse model of glaucoma. Mice were intraperitoneally injected with control substances or various doses of EPO, starting at the age of 6 months and continuing for an additional 2, 4, or 6 months. RGCs were labeled retrogradely by a gold tracer. IOP was measured with a microelectric-mechanical system, and EPO receptor (EPOR) expression was detected by immunohistochemistry. Axonal death in the optic nerve was quantified by para-phenylenediamine staining, and a complete blood count system was used to measure the number of erythrocytes., Results: In DBA/2J mice, the average number of viable RGCs significantly decreased from 4 months to 10 months, with an inverse correlation between the number of dead optic nerve axons and viable RGCs. Treatment with EPO at doses of 3000, 6000, and 12,000 U/kg body weight per week all prevented significant RGC loss, compared with untreated DBA/2J control animals. EPO effects were similar to those of memantine, a known neuroprotective agent. IOP, in contrast, was unchanged by both EPO and memantine. Finally, EPOR was expressed in the RGC layer in both DBA/2J and C57BL/6J mice., Conclusions: EPO promoted RGC survival in DBA/2J glaucomatous mice without affecting IOP. These results suggest that EPO may be a potential therapeutic neuroprotectant in glaucoma.

Purpose: The interaction of advanced glycation end products (AGEs) with their receptors is hypothesized to be involved in the development of diabetic retinopathy. In the present study, the role of an AGE receptor, RAGE, was investigated in the development of diabetic retinopathy in vivo., Methods: C57/BJ6 and RAGE-transgenic mice that carried human RAGE genetic DNA under the control of the murine flk-1 promoter were made diabetic with streptozocin. Three months after the onset of diabetes, the soluble form of RAGE (sRAGE) or mouse serum albumin was injected intraperitoneally at 100 mug/d for 14 consecutive days. After the final injection, blood-retinal barrier breakdown, retinal leukostasis, expression of VEGF and ICAM-1, and expression of RAGE in the retina were investigated., Results: Blood-retinal barrier breakdown and increased leukostasis were associated with the experimental diabetes in the C57/BJ6 mice. These changes were significantly augmented in RAGE-transgenic mice. The blood-retinal barrier breakdown and leukostasis in the diabetic C57/BJ6 and RAGE-transgenic mice were accompanied by increased expression of VEGF and ICAM-1 in the retina. The systemic administration of sRAGE significantly inhibited blood-retinal barrier breakdown, leukostasis, and expression of ICAM-1 in the retina in both the diabetic C57/BJ6 and RAGE-transgenic mice. The expression of RAGE was slightly increased in the retinal vessels in diabetic or RAGE-transgenic mice. Furthermore, a strong induction of RAGE was observed in the retinal vessels of diabetic RAGE-transgenic mice., Conclusions: This study further demonstrates the role of the AGEs and RAGE axis in blood-retinal barrier breakdown and the retinal leukostasis, which are characteristic clinical symptoms of diabetic retinopathy. Furthermore, these data demonstrate that blocking AGE bioactivity may be effective for the treatment of diabetic retinopathy.

Both clinical and preclinical findings have implicated vascular endothelial growth factor (VEGF) in the pathophysiology of diabetic macular edema (DME). VEGF is both a potent enhancer of vascular permeability and a key inducer of angiogenesis. VEGF levels are elevated in the eyes of patients with DME, and in animal models of diabetes this elevation coincides with the breakdown of the blood-retinal barrier. Moreover, injection of VEGF (the VEGF165 isoform in particular) into healthy eyes of animals can induce diabetes-associated ocular pathologies.Pegaptanib, a novel RNA aptamer currently used in the treatment of agerelated macular degeneration, binds and inactivates VEGF165 and has been shown in animal models to reverse the blood-retinal barrier breakdown associated with diabetes. These findings formed the basis of a phase II trial involving 172 patients with DME, in which intravitreous pegaptanib (0.3 mg, 1 mg, 3 mg) or sham injections were administered every 6 weeks for 12 weeks, with the option of continuing for 18 more weeks or undergoing laser treatment. Compared to sham, patients receiving 0.3 mg displayed superior visual acuity (p = 0.04) as well as a reduction in retinal thickness of 68 micrometers compared to a slight increase under sham treatment (p = 0.021). These data support the use of pegaptanib in the treatment of DME.

Purpose: The wet form of age-related macular degeneration (AMD) occurs as a consequence of abnormal blood vessel growth from the choroid into the retina. Pathological angiogenesis during tumor growth and ocular disease has been associated with specific exposure of cryptic extracellular matrix epitopes. We investigated the presence of cryptic collagen IV epitopes in a murine model of choroidal neovascularization (CNV), and tested the effect on blood vessel growth of H8, a humanized antibody directed against a cryptic collagen type IV epitope., Methods: To induce experimental CNV in adult C57BL/6 mice, Bruch's membrane was ruptured using a diode laser. Subsequently, mice were treated with daily intraperitoneal (i.p.) injections of either H8 (10 mg/kg or 30 mg/kg) or an isotype-matched antibody control. Two weeks postinjection, choroidal flat mounts were immunostained with the blood vessel marker platelet/endothelial cell adhesion molecule-1 (PECAM-1) and H8. CNV was visualized using fluorescence microscopy and the CNV lesion area measured using Open Lab software., Results: Collagen type IV and the cryptic epitope were observed at the site of laser-induced lesions. Staining with H8 was first observed three days post injury, two days after MMP2 expression in CNV lesions, becoming most intense five days following laser injury and extending beyond the area of neovascularization. At 14 days post injury, H8 staining was reduced in intensity, colocalized with the area of CNV, and was nearly absent from the underlying choroidal vessels. In addition, mice treated with H8 had a significant dose-dependent decrease in the area of CNV as compared to isotype-matched antibody controls., Conclusions: Results suggest that exposure of cryptic collagen type IV epitopes is associated with the incidence of CNV and that the humanized antibody H8 may provide a new treatment for CNV.

Vascular endothelial growth factor (VEGF) is a central regulator of both physiological and pathological angiogenesis. Pegaptanib, a 28-nucleotide RNA aptamer specific for the VEGF(165) isoform, binds to it in the extracellular space, leaving other isoforms unaffected, and inhibits such key VEGF actions as promotion of endothelial cell proliferation and survival, and vascular permeability. Pegaptanib already has been examined as a treatment for two diseases associated with ocular neovascularization, age-related macular degeneration (AMD) and diabetic macular edema (DME). Preclinical studies have shown that VEGF(165) alone mediates pathological ocular neovascularization and that its inactivation by pegaptanib inhibits the choroidal neovascularization observed in patients with neovascular AMD. In contrast, physiological vascularization, which is supported by the VEGF(121) isoform, is unaffected by this inactivation of VEGF(165). In addition, animal model studies have shown that intravitreous injection of pegaptanib can inhibit the breakdown of the blood-retinal barrier characteristic of diabetes and even can reverse this damage to some degree. These preclinical findings formed the basis for randomized controlled trials examining the efficacy of pegaptanib as a therapy for AMD and DME. The VEGF Inhibition Study in Ocular Neovascularization (VISION) trial comprising two replicate, pivotal phase 3 studies, demonstrated that intravitreous injection of pegaptanib resulted in significant clinical benefit, compared with sham injection, for all prespecified clinical end points, irrespective of patient demographics or angiographic subtype, and led to pegaptanib's approval as a treatment for AMD. A phase 2 trial has provided support for the efficacy of intravitreous pegaptanib in the treatment of DME.

VEGF plays a pivotal role in the neovascularization of the choroid in AMD. Anti-VEGF agents have been developed to target VEGF itself or its receptor signal transduction pathway, and have shown promising results in clinical trials. The combination of anti-VEGF strategies with established treatment modalities may have additional efficacy. Safe and effective drug-delivery systems are also required for the successful anti-VEGF therapies for AMD and other ocular diseases with CNV.

Objective: To evaluate the efficacy of a second year of pegaptanib sodium therapy in patients with neovascular age-related macular degeneration (AMD)., Design: Two concurrent, multicenter, randomized, double-masked, sham-controlled studies (V.I.S.I.O.N. [Vascular Endothelial Growth Factor Inhibition Study in Ocular Neovascularization] trials)., Participants: Patients with all angiographic neovascular lesion compositions of AMD were enrolled. In combined analyses, 88% (1053/1190) were re-randomized at week 54, and 89% (941/1053) were assessed at week 102., Interventions: At week 54, those initially assigned to pegaptanib were re-randomized (1:1) to continue or discontinue therapy for 48 more weeks (8 injections). Those initially assigned to sham were re-randomized to continue sham, discontinue sham, or receive 1 of 3 pegaptanib doses., Main Outcome Measures: Mean change in visual acuity (VA) over time and mean change in the standardized area under the curve of VA and proportions of patients experiencing a loss of > or =15 letters from week 54 to week 102; losing <15 letters (responders) from baseline to week 102; gaining > or =0, > or =1, > or =2, and > or =3 lines of VA; and progressing to legal blindness (20/200 or worse)., Results: In combined analysis, mean VA was maintained in patients continuing with 0.3-mg pegaptanib compared with those discontinuing therapy or receiving usual care. In patients who continued pegaptanib, the proportion who lost >15 letters from baseline in the period from week 54 to week 102 was half (7%) that of patients who discontinued pegaptanib or remained on usual care (14% for each). Kaplan-Meier analysis showed that patients continuing 0.3-mg pegaptanib for a second year were less likely to lose > or =15 letters than those re-randomized to discontinue after 1 year (P<0.05). The proportion of patients gaining vision was higher for those assigned to 2 years of 0.3-mg pegaptanib than receiving usual care. Progression to legal blindness was reduced for patients continuing 0.3-mg pegaptanib for 2 years., Conclusions: Continuing visual benefit was observed in patients who were randomized to receive therapy with pegaptanib in year 2 of the V.I.S.I.O.N. trials when compared with 2 years' usual care or cessation of therapy at year 1.

Objective: To evaluate the safety of pegaptanib sodium injection, a specific vascular endothelial growth factor (VEGF) antagonist, in the treatment of neovascular age-related macular degeneration (AMD) during 2 years of therapy., Design: Two concurrent, prospective, randomized, multicenter, double-masked, sham-controlled studies., Methods: Patients with all angiographic choroidal neovascularization lesion compositions of AMD received either intravitreous pegaptanib sodium (0.3 mg, 1 mg, 3 mg) or sham injections every 6 weeks for 54 weeks. Those initially assigned to pegaptanib were re-randomized (1:1) to continue or discontinue therapy for 48 more weeks; sham-treated patients were re-randomized (1:1:1:1:1) to continue sham, discontinue, or receive one of the pegaptanib doses., Main Outcome Measures: All reported adverse events, serious adverse events, and deaths., Participants: In year 1, 1190 subjects received at least one study treatment (0.3 mg, n = 295; 1 mg, n = 301; 3 mg, n = 296; sham, n = 298); 7545 intravitreous injections of pegaptanib were administered. In year 2, 425 subjects (0.3 mg, n = 128; 1 mg, n = 126; 3 mg, n = 120; sham, n = 51) continued the same masked treatment as in year 1 and received at least one study treatment in year 2; 2663 intravitreous injections of pegaptanib were administered in these subjects., Results: All doses of pegaptanib were well tolerated. The most common ocular adverse events were transient, mild to moderate in intensity, and attributed to the injection preparation and procedure. There was no evidence of an increase in deaths, in events associated with systemic VEGF inhibition (e.g., hypertension, thromboembolic events, serious hemorrhagic events), or in severe ocular inflammation, cataract progression, or glaucoma in pegaptanib-treated patients relative to sham-treated patients. In year 1, serious injection-related complications included endophthalmitis (12 events, 0.16%/injection), retinal detachment (RD) (6 events [4 rhegmatogenous, 2 exudative], 0.08%/injection), and traumatic cataract (5 events, 0.07%/injection). Most cases of endophthalmitis followed violations of the injection preparation protocol. In patients receiving pegaptanib for >1 year, there were no reports of endophthalmitis or traumatic cataract in year 2; RD was reported in 4 patients (all rhegmatogenous, 0.15%/injection)., Conclusion: The 2-year safety profile of pegaptanib sodium is favorable in patients with exudative AMD.

'Vascular endothelial growth factor-A (VEGF-A) blockade has been recently validated as an effective strategy for the inhibition of new blood vessel growth in cancer and ocular pathologies. However, several studies have also shown that anti-VEGF therapy may not be as effective in the treatment of established unwanted blood vessels, suggesting they may become less dependent on VEGF-A for survival. The VEGF-A dependence of vessels may be related to the presence of vascular mural cells (pericytes or smooth muscle cells). Mural cell recruitment to the growing endothelial tube is regulated by platelet-derived growth factor-B (PDGF-B) signaling, and interference with this pathway causes disruption of endothelial cell-mural cell interactions and loss of mural cells. We have investigated the basis of blood vessel dependence on VEGF-A in models of corneal and choroidal neovascularization using a combination of reagents (an anti-VEGF aptamer and an anti-PDGFR-beta antibody) to inhibit both the VEGF-A and PDGF-B signaling pathways. We demonstrate that neovessels become refractory to VEGF-A deprivation over time. We also show that inhibition of both VEGF-A and PDGF-B signaling is more effective than blocking VEGF-A alone at causing vessel regression in multiple models of neovascular growth. These findings provide insight into blood vessel growth factor dependency and validate a combination therapy strategy for enhancing the current treatments for ocular angiogenic disease.

Aptamers are oligonucleotide ligands that are selected for high-affinity binding to molecular targets. Pegaptanib sodium (Macugen; Eyetech Pharmaceuticals/Pfizer) is an RNA aptamer directed against vascular endothelial growth factor (VEGF)-165, the VEGF isoform primarily responsible for pathological ocular neovascularization and vascular permeability. After nearly a decade of preclinical development to optimize and characterize its biological effects, pegaptanib was shown in clinical trials to be effective in treating choroidal neovascularization associated with age-related macular degeneration. Pegaptanib therefore has the notable distinction of being the first aptamer therapeutic approved for use in humans, paving the way for future aptamer applications.

Objective: To study effects of intravitreal pegaptanib (Macugen) on retinal neovascularization., Design: Retrospective analysis of a randomized clinical trial. PARTICIPANTS, INTERVENTION, AND MAIN OUTCOME MEASURES: Individuals with retinal neovascularization identified from a multicenter, randomized, controlled trial evaluating pegaptanib for treatment of diabetic macular edema, with a best-corrected visual acuity letter score between 68 and 25 (approximate Snellen equivalent between 20/50 and 20/320) and receiving a sham injection or intravitreal pegaptanib (0.3 mg, 1 mg, 3 mg) administered at study entry, week 6, and week 12, with additional injections and/or focal photocoagulation as needed during the ensuing 18 weeks, up to a maximum of 6 pegaptanib/sham therapies, were evaluated. Scatter panretinal photocoagulation before study enrollment was permitted, but not within 6 months of randomization and study entry. Changes in retinal neovascularization were assessed on fundus photographs and fluorescein angiograms graded at a reading center in a masked fashion., Results: Of 172 participants, 19 had retinal neovascularization in the study eye at baseline. Excluding 1 who had scatter photocoagulation 13 days before randomization and 2 with no follow-up photographs, 1 of the remaining 16 subjects had panretinal photocoagulation during study follow-up. Of these 16 subjects, 8 of 13 (62%) in a pegaptanib treatment group (including the one receiving panretinal photocoagulation), 0 of 3 in the sham group, and 0 of 4 fellow (nonstudy) eyes showed either regression of neovascularization on fundus photographs or regression or absence of fluorescein leakage from neovascularization (or both) at 36 weeks. In 3 of 8 with regression, neovascularization progressed at week 52 after cessation of pegaptanib at week 30., Conclusions: Most subjects with retinal neovascularization at baseline assigned to pegaptanib showed regression of neovascularization by week 36. These findings suggest a direct effect of pegaptanib upon retinal neovascularization in patients with diabetes mellitus.

Objective: To evaluate the safety and efficacy of pegaptanib sodium injection (pegaptanib) in the treatment of diabetic macular edema (DME)., Design: Randomized, double-masked, multicenter, dose-ranging, controlled trial., Participants: Individuals with a best-corrected visual acuity (VA) between 20/50 and 20/320 in the study eye and DME involving the center of the macula for whom the investigator judged photocoagulation could be safely withheld for 16 weeks., Intervention: Intravitreous pegaptanib (0.3 mg, 1 mg, 3 mg) or sham injections at study entry, week 6, and week 12 with additional injections and/or focal photocoagulation as needed for another 18 weeks. Final assessments were conducted at week 36., Main Outcome Measures: Best-corrected VA, central retinal thickness at the center point of the central subfield as assessed by optical coherence tomography measurement, and additional therapy with photocoagulation between weeks 12 and 36., Results: One hundred seventy-two patients appeared balanced for baseline demographic and ocular characteristics. Median VA was better at week 36 with 0.3 mg (20/50), as compared with sham (20/63) (P = 0.04). A larger proportion of those receiving 0.3 mg gained VAs of > or =10 letters (approximately 2 lines) (34% vs. 10%, P = 0.003) and > or =15 letters (18% vs. 7%, P = 0.12). Mean central retinal thickness decreased by 68 microm with 0.3 mg, versus an increase of 4 microm with sham (P = 0.02). Larger proportions of those receiving 0.3 mg had an absolute decrease of both > or =100 microm (42% vs. 16%, P = 0.02) and > or =75 microm (49% vs. 19%, P = 0.008). Photocoagulation was deemed necessary in fewer subjects in each pegaptanib arm (0.3 mg vs. sham, 25% vs. 48%; P = 0.04). All pegaptanib doses were well tolerated. Endophthalmitis occurred in 1 of 652 injections (0.15%/injection; i.e., 1/130 [0.8%] pegaptanib subjects) and was not associated with severe visual loss., Conclusions: In this phase II trial, subjects assigned to pegaptanib had better VA outcomes, were more likely to show reduction in central retinal thickness, and were deemed less likely to need additional therapy with photocoagulation at follow-up.

Angiogenesis has a causal role in many diseases, including neovascular age-related macular degeneration (AMD). Identification of key regulators of angiogenesis, including vascular endothelial growth factor (VEGF), fibroblast growth factor 2, pigment epithelium-derived growth factor, angiopoietins and extracellular matrix molecules, has facilitated the development of novel therapeutic agents that target the underlying pathological angiogenic process. Among these, VEGF serves as a "master switch" for many ocular neovascular conditions through its promotion of endothelial cell proliferation and survival, vascular permeability and ocular inflammation. Two anti-VEGF agents are now clinically available: bevacizumab, an antibody for metastatic colorectal cancer, and pegaptanib sodium, an aptamer for neovascular AMD. Unlike bevacizumab, which binds all VEGF isoforms, pegaptanib targets only VEGF165, the isoform responsible for pathological ocular neovascularization and thus an ideal target for treatment of AMD. Although other therapies targeting angiogenesis in AMD are in clinical development, to date, pegaptanib is the only therapy approved by the Food and Drug Administration of the United States for the treatment of all neovascular AMD and represents a valuable addition to the hitherto limited options available for patients.

The leading causes of blindness are retinal and choroidal diseases manifesting abnormal vessel permeability and growth. Scientists have sought to understand the mechanisms underlying these pathologic conditions with the hope of developing directed and effective pharmacologic therapies. Research has yielded important new mechanistic data, making possible the development of new drugs. One of the most important targets to have emerged is a secreted protein named vascular endothelial growth factor. This review will summarize the current state of our knowledge regarding this growth factor and outline some important questions that remain to be answered.

Diabetic retinopathy is a leading cause of adult vision loss and blindness. Much of the retinal damage that characterizes the disease results from retinal vascular leakage and nonperfusion. Diabetic retinal vascular leakage, capillary nonperfusion, and endothelial cell damage are temporary and spatially associated with retinal leukocyte stasis in early experimental diabetes. Retinal leukostasis increases within days of developing diabetes and correlates with the increased expression of retinal intercellular adhesion molecule-1 (ICAM-1) and CD18. Mice deficient in the genes encoding for the leukocyte adhesion molecules CD18 and ICAM-1 were studied in two models of diabetic retinopathy with respect to the long-term development of retinal vascular lesions. CD18-/- and ICAM-1-/- mice demonstrate significantly fewer adherent leukocytes in the retinal vasculature at 11 and 15 months after induction of diabetes with STZ. This condition is associated with fewer damaged endothelial cells and lesser vascular leakage. Galactosemia of up to 24 months causes pericyte and endothelial cell loss and formation of acellular capillaries. These changes are significantly reduced in CD18- and ICAM-1-deficient mice. Basement membrane thickening of the retinal vessels is increased in long-term galactosemic animals independent of the genetic strain. Here we show that chronic, low-grade subclinical inflammation is responsible for many of the signature vascular lesions of diabetic retinopathy. These data highlight the central and causal role of adherent leukocytes in the pathogenesis of diabetic retinopathy. They also underscore the potential utility of anti-inflammatory treatment in diabetic retinopathy.