Macular Degeneration: Adamis AP

Starita C, Patel M, Katz B, Adamis AP. · Pfizer Ltd., Sandwich, UK. · Dev Ophthalmol. · Pubmed #17245083 No free full text.

Abstract: 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.

Ng EW, Adamis AP. · (OSI) Eyetech, Inc., New York, New York 10036, USA. · Ann N Y Acad Sci. · Pubmed #17145936 No free full text.

Abstract: 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.

Ng EW, Shima DT, Calias P, Cunningham ET, Guyer DR, Adamis AP. · Eyetech Pharmaceuticals, Inc., 3 Times Square, 12th Floor, New York, New York 10036, USA. · Nat Rev Drug Discov. · Pubmed #16518379 No free full text.

Abstract: 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.

Ng EW, Adamis AP. · Eyetech Pharmaceuticals, Inc., New York, NY 10036, USA. · Can J Ophthalmol. · Pubmed #15947805 links to  free full text

Abstract: 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.

Ambati J, Ambati BK, Yoo SH, Ianchulev S, Adamis AP. · Ocular Angiogenesis Laboratory, Department of Ophthalmology, University of Kentucky, Lexington, USA. · Surv Ophthalmol. · Pubmed #12745003 No free full text.

Abstract: Age-related macular degeneration is the principal cause of registered legal blindness among those aged over 65 in the United States, western Europe, Australia, and Japan. Despite intensive research, the precise etiology of molecular events that underlie age-related macular degeneration is poorly understood. However, investigations on parallel fronts are addressing this prevalent public health problem. Sophisticated biochemical and biophysical techniques have refined our understanding of the pathobiology of drusen, geographic atrophy, and retinal pigment epithelial detachments. Epidemiological identification of risk factors has facilitated an intelligent search for underlying mechanisms and fueled clinical investigation of behavior modification. Gene searches have not only brought us to the cusp of identifying the culpable gene loci in age-related macular degeneration, but also localized genes responsible for other macular dystrophies. Recent and ongoing investigations, often cued by tumor biology, have revealed an important role for various growth factors, particularly in the neovascular form of the condition. Transgenic and knockout studies have provided important mechanistic insights into the development of choroidal neovascularization, the principal cause of vision loss in age-related macular degeneration. This in turn has culminated in preclinical and clinical trials of directed molecular interventions.

Husain D, Ambati B, Adamis AP, Miller JW. · Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA. · Ophthalmol Clin North Am. · Pubmed #12064086 No free full text.

Abstract: AMD is a poorly understood disease at this time. Since it is the leading cause of blindness in the elderly in the developed world, there is a pressing need for better treatment. Therefore, there is extensive ongoing research in both pathogenesis and therapy of AMD. Epidemiological studies have shown significant risk associated with increasing age and cigarette smoking, future studies may identify environmental risk factors though at present studies have been inconclusive. Genetic studies may identify subgroups of disease and thus help provide a selective approach to treatment. The vascular model of AMD may provide better understanding of the blood flow and post capillary resistance and help in early and newer intervention in the disease. Vascular endothelial growth factor has been extensively studied in choroidal neovascularization. It has been demonstrated in human and animal models of CNV and VEGF antagonists are currently in clinical trial. Extensive work is ongoing to prevent and treat CNV with antiangiogenic agents.

Wroblewski JJ, Wells JA, Adamis AP, Buggage RR, Cunningham ET, Goldbaum M, Guyer DR, Katz B, Altaweel MM, Anonymous00045. · Cumberland Valley Retina Consultants, Hagerstown, Maryland 21740, USA. · Arch Ophthalmol. · Pubmed #19365011 No free full text.

Abstract: 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.

Anonymous00151, Apte RS, Modi M, Masonson H, Patel M, Whitfield L, Adamis AP. · Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of Medicine, St. Louis, Missouri 63110, USA. · Ophthalmology. · Pubmed #17509689 No free full text.

Abstract: 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.

Cunningham ET, Adamis AP, Altaweel M, Aiello LP, Bressler NM, D'Amico DJ, Goldbaum M, Guyer DR, Katz B, Patel M, Schwartz SD, Anonymous00243. · Stanford University, USA. · Ophthalmology. · Pubmed #16154196 No free full text.

Abstract: 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.

Gragoudas ES, Adamis AP, Cunningham ET, Feinsod M, Guyer DR, Anonymous00336. · Retina Service, Massachusetts Eye and Ear Infirmary and Harvard Medical School, 243 Charles St., Boston, MA 02114, USA. · N Engl J Med. · Pubmed #15625332 links to  free full text

Abstract: 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.

Adamis AP. · Jerini Ophthalmic, New York, New York 10020, USA. · Retina. · Pubmed #19553800 No free full text.

Abstract: 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.

Singerman LJ, Masonson H, Patel M, Adamis AP, Buggage R, Cunningham E, Goldbaum M, Katz B, Guyer D. · Retina Associates of Cleveland, 3401 Enterprise Parkway, Suite 300, Cleveland, OH 44122, USA. · Br J Ophthalmol. · Pubmed #18614570 links to  free full text

Abstract: 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.

Javitt JC, Zlateva GP, Earnshaw SR, Pleil AM, Graham CN, Brogan AJ, Shah SN, Adamis AP. · The Potomac Institute for Policy Studies, Arlington, VA, USA. · Value Health. · Pubmed #18179676 No free full text.

Abstract: 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.

Nishijima K, Ng YS, Zhong L, Bradley J, Schubert W, Jo N, Akita J, Samuelsson SJ, Robinson GS, Adamis AP, Shima DT. · R&D Consultants, Barnet, Herts, UK. · Am J Pathol. · Pubmed #17591953 links to  free full text

Abstract: 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.

Jo N, Ju M, Nishijima K, Robinson GS, Adamis AP, Shima DT, Mailhos C. · OSI Eyetech, Eyetech Research Center, Lexington, MA 02421, USA. · Mol Vis. · Pubmed #17110907 links to  free full text

Abstract: 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.

Anonymous00326, Chakravarthy U, Adamis AP, Cunningham ET, Goldbaum M, Guyer DR, Katz B, Patel M. · Centre for Vision Sciences, The Queen's University of Belfast and The Royal Victoria Hospital, Belfast, United Kingdom. · Ophthalmology. · Pubmed #16828500 No free full text.

Abstract: 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.

Anonymous00201, D'Amico DJ, Masonson HN, Patel M, Adamis AP, Cunningham ET, Guyer DR, Katz B. · Department of Ophthalmology, Harvard Medical School, Retina Service, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 02114, USA. · Ophthalmology. · Pubmed #16647134 No free full text.

Abstract: 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.

Adamis AP, Altaweel M, Bressler NM, Cunningham ET, Davis MD, Goldbaum M, Gonzales C, Guyer DR, Barrett K, Patel M, Anonymous00106. · No affiliation provided · Ophthalmology. · Pubmed #16343627 No free full text.

Abstract: 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.

Adamis AP, Aiello LP, D'Amato RA. · Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA. · Angiogenesis. · Pubmed #14517440 No free full text.

Abstract: Ocular angiogenesis is responsible for the majority of irreversible blindness in the developed world [1]. This debilitating complication affects all age groups and characterizes such diverse and widespread diseases as trachoma, retinopathy of prematurity, diabetic retinopathy, neovascular glaucoma and age-related macular degeneration. Although numerous relatively rare conditions also exhibit ocular angiogenesis, the aim of this review will be to briefly summarize our current knowledge regarding the clinical and laboratory findings of the most epidemiologically significant diseases. We will also describe current concepts regarding the pathogenesis of ocular angiogenesis. In this review the term 'neovascularization', which is more prevalent in the ophthalmic literature, will be used to describe the development of pathological new vessels and should be considered synonymous with 'angiogenesis'.

Krzystolik MG, Afshari MA, Adamis AP, Gaudreault J, Gragoudas ES, Michaud NA, Li W, Connolly E, O'Neill CA, Miller JW. · Retina Service, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02114, USA. · Arch Ophthalmol. · Pubmed #11879138 No free full text.

Abstract: OBJECTIVE: To evaluate the safety and efficacy of intravitreal injections of an antigen-binding fragment of a recombinant humanized monoclonal antibody directed toward vascular endothelial growth factor (rhuFab VEGF) in a monkey model of choroidal neovascularization (CNV). METHODS: In phase 1 of the study, each animal received intravitreal injections, 500 microg per eye, of rhuFab VEGF in one eye (prevention eye), while the contralateral eye received rhuFab VEGF vehicle (control eye) at 2-week intervals. On day 21, laser photocoagulation was performed to induce CNV. In phase 2, the vehicle-treated eye was crossed over and both eyes received 500 microg of rhuFab VEGF beginning 21 days following laser-induced injury at days 42 and 56. The eyes were monitored by ophthalmic examinations, color photographs, and fluorescein angiography. RESULTS: rhuFab VEGF did not cause any ocular hemorrhages. All eyes treated with rhuFab VEGF developed acute anterior chamber inflammation within 24 hours of the first injection that resolved within 1 week, and this inflammation was less severe with subsequent injections. The incidence of CNV, defined angiographically, was significantly lower in the prevention eyes than the control eyes (P<.001). Subsequent treatments were associated with less leakage in eyes with established CNV that were crossed over from the control eyes to the treatment eyes (P =.001). CONCLUSIONS: Intravitreal rhuFab VEGF injections prevented formation of clinically significant CNV in cynomolgus monkeys and decreased leakage of already formed CNV with no significant toxic effects. CLINICAL RELEVANCE: This study provides the nonclinical proof of principle for ongoing clinical studies of intravitreally injected rhuFab VEGF in patients with neovascular age-related macular degeneration.

Schwesinger C, Yee C, Rohan RM, Joussen AM, Fernandez A, Meyer TN, Poulaki V, Ma JJ, Redmond TM, Liu S, Adamis AP, D'Amato RJ. · Albert Ludwigs University, Freiburg, Germany. · Am J Pathol. · Pubmed #11238064 links to  free full text

Abstract: Choroidal neovascularization in age-related macular degeneration is a frequent and poorly treatable cause of vision loss in elderly Caucasians. This choroidal neovascularization has been associated with the expression of vascular endothelial growth factor (VEGF). In current animal models choroidal neovascularization is induced by subretinal injection of growth factors or vectors encoding growth factors such as VEGF, or by disruption of the Bruch's membrane/retinal pigment epithelium complex with laser treatment. We wished to establish a transgenic murine model of age-related macular degeneration, in which the overexpression of VEGF by the retinal pigment epithelium induces choroidal neovascularization. A construct consisting of a tissue-specific murine retinal pigment epithelium promoter (RPE(65) promoter) coupled to murine VEGF(164) cDNA with a rabbit beta-globin-3' UTR was introduced into the genome of albino mice. Transgene mRNA was expressed in the retinal pigment epithelium at all ages peaking at 4 months. The expression of VEGF protein was increased in both the retinal pigment epithelium and choroid. An increase of intravascular adherent leukocytes and vessel leakage was observed. Histopathology revealed intrachoroidal neovascularization that did not penetrate through an intact Bruch's membrane. These results support the hypothesis that additional insults to the integrity of Bruch's membrane are required to induce growth of choroidal vessels into the subretinal space as seen in age-related macular degeneration. This model may be useful to screen for inhibitors of choroidal vessel growth.