Pharmacokinetics of a long-lasting anti-VEGF fusion protein in rabbit

Conbercept(KH902), a recombinant fusion protein in clinical trial II/III, shows good potential to treat the neovascular age-related macular degeneration (AMD). This investigation evaluated its ocular pharmacokinetics and pharmacodynamic profile in rabbits following intravitreal administration (IVT). Rabbits (n = 120) received single bilateral conbercept IVT administration or single IV administration. Conbercept concentrations in ocular tissues and serum were measured after dosing. VEGF concentration was also measured simultaneously. The results showed that conbercept rapidly distributed from vitreous into targeted tissues and lasted over 81 days. Clearance in ocular tissues was parallel and exhibited a terminal half of 2.5-4.2 days. The drug exposure in the retina was 1/4 to 1/5 of that in vitreous. Serum conbercept concentrations after IVT dosing were low and bioavailability was approximately 44%. And single intravitreal injection induced that ocular VEGF concentration declined over 60 days and serum VEGF concentration decreased for a short time but rebounded to higher level than baseline later. All these indicated conbercept good pharmacokinetic profile in rabbits, with good ocular tropism and systemic tolerance. Combined with the efficacy data from our earlier in vitro and in vivo studies, it should have a promising clinical application for AMD treatment.     

Simultaneous but not prior inhibition of VEGF165 enhances the efficacy of photodynamic therapy in multiple models of ocular neovascularization

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.     

Pegaptanib sodium for ocular vascular disease

Pegaptanib sodium (Macugen) is a selective RNA aptamer that inhibits vascular endothelial growth factor (VEGF) 165 , the VEGF isoform primarily responsible for pathologic ocular neovascularization and vascular permeability, while sparing the physiological isoform VEGF 121 . After more than 10 years in development and preclinical study, pegaptanib was shown in clinical trials to be effective in treating choroidal neovascularization associated with age-related macular degeneration. Its excellent ocular and systemic safety profile has also been confirmed in patients receiving up to three years of therapy. Early, well-controlled studies further suggest that pegaptanib may provide therapeutic benefit for patients with diabetic macular edema, proliferative diabetic retinopathy and retinal vein occlusion. Notably, pegaptanib was the first available aptamer approved for therapeutic use in humans and the first VEGF inhibitor available for the treatment of ocular vascular diseases.     

Tolerability and pharmacokinetics of intravitreal sirolimus

Abstract Purpose: To evaluate the pharmacokinetics (PK) and tolerability of a proprietary sirolimus depot-forming ocular formulation in rabbits and humans after a single intravitreal (IVT) injection. Methods: New Zealand White (NZW) rabbits were intravitreally injected in both eyes with an injectable formulation in 5 (3 PK and 2 tolerability) studies. The rabbits received up to approximately 220?μg sirolimus per eye. At the desired timing post-injection, the animals were euthanized; both eyes were enucleated, frozen, and dissected to separate sclera, retina/choroid, and vitreous humor (VH). Whole blood (WB) samples were obtained at each time point before euthanasia. In clinical trials, patients received an IVT injection of approximately 352?μg sirolimus. Sirolimus concentrations in ocular tissues and WB samples were measured using liquid chromatography/tandem mass spectrometry (LC/MS/MS). In both single- and repeat-dose tolerability studies, systemic and ocular adverse effects were evaluated. Results: After IVT administration, sirolimus formed a depot in the VH. During dissolution, concentrations in VH were dose related and exhibited continuous release from the depot. This was characterized by a gradient of sirolimus concentration in the order of VH > retina/choroid > sclera > WB, and the concentrations were maintained for approximately 2 months after the IVT injection. After repeat dosing (132?μg), no drug accumulation was seen in the ocular tissue or systemically. In clinical studies, the highest blood levels were <2?ng/mL at day 2, and half-time (t(1/2)) was 8-9 days. There was no accumulation at day 30 after the IVT injection (up to 352?μg). Safety studies conducted on rabbits indicated good local tolerability. Sirolimus-related effects were limited to minor incipient cataract findings and mild lenticular changes. In the clinical studies where sirolimus was intravitreally administered up to 352?μg, injections were well tolerated. Conclusions: Sustained IVT delivery was achieved in a dose-dependent fashion after the IVT injection of a proprietary sirolimus depot-forming ocular formulation. Across the tolerability and safety studies, no significant findings were observed for systemic and ocular tolerability. The human WB levels were well below the daily trough systemic blood level range required for systemic immunosuppression. An IVT injection of sirolimus has a PK and safety profile that is favorable for treating inflammatory conditions of the eye, such as non-infectious uveitis, and warrants further investigation in humans.     

Safety and efficacy of intravitreal bevacizumab followed by pegaptanib maintenance as a treatment regimen for age-related macular degeneration.

BACKGROUND AND OBJECTIVE: Vascular endothelial growth factor (VEGF)-A, both necessary and sufficient in promoting ocular neovascularization, is an attractive therapeutic target. Combining nonselective and selective VEGF blockade may provide clinical benefit with minimal risks in the treatment of neovascular age-related macular degeneration (AMD). PATIENTS AND METHODS: Twenty patients with all subtypes of neovascular AMD and a broad range of baseline vision were treated with intravitreal bevacizumab followed by pegaptanib sodium for 54 weeks. Visual acuity measurements, biomicroscopy, funduscopy, fluorescein angiography, optical coherence tomography, and adverse event assessments were performed. RESULTS: Mean visual acuity improved from approximately 20/200 at baseline to 20/80. All patients experienced an improvement in retinal thickness, ranging from -47 to -297 microns. Adverse events were limited to transient irritation or redness. No significant elevation in intraocular pressure occurred following either bevacizumab or pegaptanib injections. CONCLUSIONS: Nonselective VEGF blockade with bevacizumab induction and selective VEGF165 blockade with pegaptanib as maintenance therapies may offer clinically meaningful outcomes with acceptable safety profiles in patients with AMD.     

Targeting angiogenesis, the underlying disorder in neovascular age-related macular degeneration

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.     

Systemic and ocular safety of intravitreal anti-VEGF therapies for ocular neovascular disease

The treatment of ocular neovascular diseases is being revolutionized by intravitreal therapies targeting vascular endothelial growth factor (VEGF). Two agents are approved for treating neovascular age-related macular degeneration and are being evaluated for other retinal conditions: the RNA aptamer pegaptanib and the monoclonal antibody antigen-binding fragment ranibizumab. Bevacizumab, a related antibody, is being used similarly, although its use is off-label. Pegaptanib selectively binds to a VEGF isoform identified as being especially pathogenic in the eye and spares other isoforms, whereas the other two agents nonselectively bind all VEGF isoforms. Because VEGF is involved in a wide variety of physiologic processes, the ocular and systemic safety of anti-VEGF agents is of paramount concern. I provide an overview of safety data for intravitreal anti-VEGF therapies, focusing primarily on randomized, controlled trials. For pegaptanib, an accumulation of data from pivotal trials and a dedicated systemic safety study have revealed no ocular or systemic safety concerns. For ranibizumab, the principal ocular adverse event detected in clinical trials was a low frequency of ocular inflammation, and systemic adverse events included a slightly elevated risk of nonocular hemorrhage and stroke. Safety data from properly designed randomized controlled trials for bevacizumab are not available.     

Enhanced efficacy associated with early treatment of neovascular age-related macular degeneration with pegaptanib sodium: an exploratory analysis

PURPOSE: To assess the vision benefit of treating early subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD) with pegaptanib sodium. METHODS: Exploratory analyses of week 54 vision outcomes (VEGF Inhibition Study in Ocular Neovascularization study) of subject subgroups with early disease who received 0.3 mg of pegaptanib (Groups 1 [n = 34] and 2 [n = 30]) or sham injections (usual care). Two sets of clinical characteristics typical of early disease defined the subgroups. RESULTS: Baseline characteristics were generally well balanced between treatment arms. Pegaptanib responder rates (loss of <15 letters of visual acuity) were 76% and 80% in treatment Groups 1 and 2 versus 50% and 57% for usual care Groups 1 and 2 (P = 0.03 and P = 0.05), respectively. Compared with subjects assigned to pegaptanib, those in Groups 1 and 2 receiving usual care on average lost 11.1 letters and 12.7 letters more of visual acuity (P < 0.01 and P < 0.006), respectively. Subjects assigned to usual care were approximately 10 times more likely to have severe vision loss than were those treated with pegaptanib (Group 1, 29% vs. 3%, respectively; P < 0.01). In Group 1, 12% of pegaptanib-treated subjects gained > or =15 letters of visual acuity versus 4% receiving usual care; 20% of Group 2 pegaptanib-treated subjects gained > or =15 letters of visual acuity versus none of the usual care subjects. CONCLUSION: Early detection and treatment with pegaptanib may result in superior vision outcomes in patients with neovascular AMD.     

A retrospective, pooled data analysis of the safety of pegaptanib sodium in the treatment of age-related macular degeneration in subjects with or without diabetes mellitus

ABSTRACT: BACKGROUND: To evaluate the safety of pegaptanib sodium 0.3 mg intravitreal injection in the treatment of neovascular age-related macular degeneration in subjects with or without diabetes mellitus. METHODS: A pooled, retrospective, analysis was conducted of data from 9 sponsor-administered, randomized, open-label trials. Subjects who received pegaptanib by randomization or change in dose assignment, crossover design, or protocol amendment, were included. Reports of endophthalmitis, increased intraocular pressure, retinal injury, intraocular hemorrhage, traumatic cataract, hypersensitivity reactions, stroke, myocardial infarction, and other arterial thromboembolic events defined by the Antiplatelet Trialists' Collaboration were identified by Medical Dictionary for Regulatory Activities preferred terms. Adverse events were summarized from the first injection to 42 days after the last injection. The incidence of adverse events was stratified by the presence/absence of diabetes. RESULTS: Of 1,586 subjects enrolled, 165 (10.4%) had a history of diabetes mellitus and 1,421 (89.6%) did not. The 2 populations were similar at baseline. Based on the comparison of prespecified ocular, hypersensitivity, and Antiplatelet Trialists' Collaboration event terms, the safety review did not identify any notable differences between the 2 populations. CONCLUSIONS: This retrospective analysis found no increased safety risk resulting from treatment with pegaptanib 0.3 mg in individuals with neovascular age-related macular degeneration and concomitant diabetes mellitus.     

The role of different VEGF isoforms in scar formation after glaucoma filtration surgery

Vascular endothelial growth factor (VEGF) plays an important role in both physiological and pathological angiogenesis. Our previous studies showed a differential role of VEGF isoforms in retinal physiological angiogenesis. We also demonstrated that non-selective inhibition of VEGF by bevacizumab had a beneficial effect on surgical outcome after glaucoma filtration surgery by reducing angiogenesis as well as fibrosis. However, the function of the VEGF isoforms in pathological angiogenesis and wound healing in the eye still remains unidentified. This study was designed to elucidate the differential roles of VEGF isoforms in scar formation after trabeculectomy. Furthermore, we also investigated whether pegaptanib (Macugen™, Pfizer), an aptamer which specifically blocks VEGF₁₆₅, could improve surgical outcome by reducing postoperative scarring. VEGF-R2 and neuropilin-1 (NRP-1) expression was analyzed in vitro by RT-PCR, and were found to be expressed at higher levels in human umbilical vein endothelial cells (HUVEC) as compared to Tenon fibroblasts (TF). The effect of the different VEGF isoforms (VEGF₁₂₁, VEGF₁₆₅ and VEGF₁₈₉) and pegaptanib on cell proliferation was determined via WST-1 assay. Endothelial cell proliferation was stimulated after addition of VEGF₁₂₁ and VEGF₁₆₅, whereas VEGF₁₂₁ and VEGF₁₈₉ increased fibroblast growth. These effects on proliferation were associated with an activation of the ERK pathway, as revealed using the TransAM c-Myc assay. Inhibition of the ERK pathway, by PD98059 administration, significantly reduced VEGF isoform induced cell growth. A dose-dependent reduction of endothelial cell proliferation was observed after pegaptanib administration, while only the highest dose was able to inhibit fibroblast growth. Next, the in vivo effect of pegaptanib was investigated in a rabbit model of trabeculectomy. The surgical outcome was evaluated by performing clinical investigations (IOP, bleb area, height and survival), as well as histomorphometric analyses of angiogenesis (CD31), inflammation (CD45) and fibrosis (Sirius Red). A single postoperative application of pegaptanib had a beneficial impact on surgical outcome, mainly by reducing angiogenesis, but not inflammation or collagen deposition. Repeated injections slightly improved surgical outcome, but again solely by reducing angiogenesis. In summary, our results revealed that the VEGF isoforms play a differential role in ocular wound healing: VEGF₁₆₅ and VEGF₁₂₁ predominantly affect blood vessel growth, whereas VEGF₁₈₉ is rather involved in fibrosis, an important process in wound healing.     

Are intravitreal bevacizumab and ranibizumab effective in a rat model of choroidal neovascularization?

Background  Vascular endothelial growth factor (VEGF) is an important stimulator of choroidal neovascularization (CNV). Bevacizumab (Avastin), ranibizumab (Lucentis) and pegaptanib sodium (Macugen) are anti-VEGF medications that have been used in the treatment of CNV. The purpose of our study is to evaluate the efficacy and safety of intravitreal injections of bevacizumab, ranibizumab and pegaptanib sodium in the treatment of CNV in a rat model. Methods  Multiple CNV lesions were induced by laser photocoagulation of the retina in Brown-Norway rats. After 3 weeks, 17 rats were divided into three groups and received intravitreal injections of bevacizumab, ranibizumab or pegaptanib sodium in different dosages. The lesions were evaluated by fluorescein angiography 1, 7, 14, and 28 days later to assess the efficacy of these medications. Results  Different doses of bevacizumab did not show any effect on stopping the leakage on fluorescein angiography on days 1, 7, 14, and 28. Ranibizumab and pegaptanib sodium did not stop the leakage of CNV either. No angiographic or histopathologic toxicity was observed. Conclusions  These three anti-VEGF agents did not show any therapeutic effect on stopping CNV leakage in rats. Previous experiments with ranibizumab in monkeys resulted in a significant decrease in leakage of CNV. The difference may be due to the fact that both ranibizumab and bevacizumab are humanized and species-specific. There are several studies evaluating the effect of bevacizumab in non-primates. Since bevacizumab is humanized, the results of studies on non-primates may not be similar to humans and non-human primates. Grant Support: Leir Foundation The authors have full control of the primary data and will provide it to Graefe’s Archive for Clinical and Experimental Ophthalmology at their request. Neither author has any conflict of interest, financial or otherwise, to report.     

Pegaptanib for the treatment of age-related macular degeneration

Although neovascular (wet) age-related macular degeneration (AMD) only accounts for 10-20% of all AMD, the majority (about 90%) of severe vision loss associated with AMD is due to this form. Results from recent studies have implied that vascular endothelial growth factor (VEGF), particularly VEGF(165), plays a predominant role in the development of ocular neovascularization and vascular leakage secondary to AMD. Thus VEGF is an important therapeutic target in neovascular AMD. Pegaptanib, an anti-VEGF aptamer, can selectively bind with VEGF(165) and inhibit both the growth of blood vessels and vascular leakage, and was approved by the Food and Drug Administration in the United States as the therapy for the treatment of all subtypes of neovascular AMD in December 2004. This review summaries the mechanism, preclinical and clinical studies, and adverse events of pegaptanib treatment.     

Vitreous injections of pegaptanib sodium triggering allergic reactions

PURPOSE: To report two cases of systemic allergic response associated with vitreous administration of pegaptanib sodium. DESIGN: Observational case report. METHODS: Two patients were treated for systemic allergic reactions associated with the administration of pegaptanib sodium. RESULTS: One patient developed a delayed and prolonged anaphylactoid reaction following administration of his first dose of intraocular pegaptanib sodium. The second patient received four injections of pegaptanib over the course of six months. He developed mild lip swelling and prolonged urticarial rash following the first injection, which subsided when pegaptanib was suspended. CONCLUSIONS: Severe hypersensitivity reactions may occur in association with vitreous administration of pegaptanib sodium and may be associated with prolonged urticaria and angioedema. Elderly individuals with comorbidities are at higher risk for fatality from severe hypersensitivity reactions in the ambulatory setting. Physicians administering pegaptanib sodium should review emergency response and airway procedures.     

Histologic studies of the intraocular toxicity of imatinib mesylate in rabbits

PURPOSE: To evaluate histologic signs of toxicity of the protein tyrosine kinase inhibitor, imatinib mesylate, in rabbit eyes. METHODS: Twenty Dutch-belted rabbits underwent intravitreal injections of 0.1 ml solutions of imatinib mesylate. Ten rabbits were killed and enucleated 1 week after injection of imatinib mesylate (1.65 mg (four eyes), 165 microg (four eyes), and 16.5 microg (two eyes)). Ten rabbits injected with imatinib mesylate (165 microg (five eyes) and 825 microg (five eyes)) were enucleated 1 month later. Eyes were fixed in 10% formalin and stained with haematoxylin and eosin for microscopic examination. RESULTS: All four eyes injected with 1.65 mg of imatinib mesylate and enucleated at 1 week demonstrated ocular toxicity. All four eyes injected with 165 microg and enucleated at 1 week showed no ocular toxicity. One of the two eyes injected with 16.5 microg and enucleated at 1 week revealed focal areas of subretinal fluid and retinal undulations, suggestive of retinal oedema. None of the 10 eyes injected with imatinib mesylate at either the 165 or 825 microg dose and enucleated at 1 month showed ocular toxicity. CONCLUSIONS: Imatinib mesylate at 1.65 mg caused extensive retinal toxicity in rabbit eyes. In contrast, lower doses did not appear to cause toxicity, but may be associated with retinal oedema.     

Toxicity testing of the VEGF inhibitors bevacizumab,ranibizumab and pegaptanib in rats both with and without prior retinal ganglion cell damage

Purpose: To evaluate the effects of intravitreally introduced vascular endothelial growth factor (VEGF) inhibitors in rat eyes with healthy retinal ganglion cells (RGC) and into others with N‐methyl‐D‐aspartate (NMDA)‐induced RGC damage. Methods: Bevacizumab, ranibizumab and pegaptanib were intravitreally injected each at two different concentrations. Respective vehicles of the three substances served as controls. In a different group, additionally a rat anti‐VEGF antibody was injected after NMDA treatment. Retrogradely labelled RGC were counted on retinal wholemounts 1 week or 2 months after intravitreal introduction of the VEGF inhibitors. Electron microscopy (EM) was performed on normal rat eyes 2 months after introduction of the VEGF inhibitors. Results: RGC counts in healthy rat eyes were essentially unchanged from those of the control animals after the administration of both low and high concentrations of bevacizumab, ranibizumab or pegaptanib. Compared to the other two substances, however, high doses of pegaptanib and its respective vehicle significantly decreased RGC after 1 week and led to a marked increase of mitochondrial swelling in EM. In eyes with NMDA‐induced RGC damage, no changes of RGC numbers were detected after rat anti‐VEGF antibody or bevacizumab, ranibizumab and pegaptanib at both tested concentrations. Conclusions: Even at higher doses, bevacizumab and ranibizumab showed no toxic effects on RGC in vivo in either untreated rats or in the NMDA‐induced RGC damage model. Also a rat anti‐VEGF antibody showed no adverse effects after NMDA. Anti‐VEGF therapy therefore appears safe even for eyes with additional excitotoxic RGC damage. Potential harm from the pegaptanib carrier solution at very high local concentrations cannot be excluded.     

Triamcinolone reduces neovascularization, capillary density and IGF-1 receptor phosphorylation in a model of oxygen-induced retinopathy

PURPOSE: To study the effects of intravitreous triamcinolone acetonide (TA) on neovascularization (NV), capillary density, and retinal endothelial cell (REC) viability in a model of oxygen-induced retinopathy (OIR). METHODS: Newborn rats exposed to OIR underwent intravitreous injections (right eye) at day 14 to achieve intravitreous concentrations of: dexamethasone (DEX) (0.3 mg/mL), triamcinolone (TA; 0.4-4 mg/mL), or PBS. Animals were removed to room air and at day 18, retinal flatmounts were assayed for clock hours of NV, percent peripheral avascular retina, capillary density, apoptosis, and VEGF protein. At day 15, retinas were assayed for insulin-like growth factor (IGF)-1 receptor phosphorylation (IGF-1Rphos). Human RECs exposed to TA were assayed for trypan blue exclusion or activated caspase-3. RESULTS: TA but not DEX or PBS reduced NV (ANOVA, P < 0.001), capillary density (ANOVA, P < 0.001), and systemic weight gain (ANOVA, P = 0.002). VEGF protein was not different between TA- and PBS-injected or noninjected groups. Apoptosis was not increased in vivo or in vitro between groups, but there was a dose-dependent toxic effect of TA on cultured RECs (P < 0.001). At day 15, retinas from the 4 mg/mL TA-injected OIR group had a trend toward reduced IGF-1Rphos compared with room air-raised PBS- or non-injected OIR groups. CONCLUSIONS: TA caused dose-dependent reductions in NV, retinal vascularization, and systemic weight gain associated with a reduction in IGF-1Rphos. Long-term studies are needed to assess TA toxicity in vivo. TA doses should be carefully considered before administering the drug in diseases with ongoing retinal vascular development, such as retinopathy of prematurity.     

Twelve-month safety of intravitreal injections of bevacizumab (Avastin®): results of the Pan-American Collaborative Retina Study Group (PACORES)

Background Vascular endothelial growth factor (VEGF) plays an important role in many diseases of the posterior pole that are characterized by macular edema and/or intraocular neovascularization. Recently anti-VEGF agents such as ranibizumab and pegaptanib sodium have been shown to be beneficial in the treatment of choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD). However in most parts of the world, both pegaptanib sodium and ranibizumab are not readily available. Bevacizumab, a humanized recombinant monoclonal IgG antibody that binds and inhibits all VEGF isoforms, has been proposed as an alternative treatment option. Methods A total of 1,265 consecutive patients were injected with bevacizumab for diseases such as proliferative diabetic retinopathy, diabetic macular edema, retinal vein occlusions, and CNV of several etiologies including ARMD at eight Latin American institutions from 1 September 2005 to 31 January 2006. Of these 1,265, 92 were excluded because they were injected once and lost to follow-up. The remaining 1,173 patients constitute the subjects of this retrospective, multicenter, open label, uncontrolled interventional case series that reports the cumulative systemic and ocular adverse events following intravitreal bevacizumab during 12 months of follow-up. Patients were examined at baseline and then monthly. If the patients were unable to attend the 12-month visit, a telephone interview was conducted to assess for possible systemic complications. Results A total of 4,303 intravitreal injections of bevacizumab on 1,310 eyes was reported. All 1,173 patients were accounted for at the 12-month visit. Systemic adverse events were reported in 18 (1.5%) patients. These included seven (0.59%) cases of an acute elevation of systemic blood pressure, six (0.5%) cerebrovascular accidents, five (0.4%) myocardial infarctions, two (0.17%) iliac artery aneurysms, two (0.17%) toe amputations and five (0.4%) deaths. Ocular complications included seven (0.16%) bacterial endophthalmitis, seven (0.16%) tractional retinal detachments, four (0.09%) uveitis, and a case (0.02%) each of rhegmatogenous retinal detachment and vitreous hemorrhage. Conclusion Despite the limited follow-up, repeated intravitreal injections of either 1.25 mg or 2.5 mg of bevacizumab appears to be safe and well tolerated during the 1st year. Presented in part at the combined Club Jules Gonin-Retina Society Meeting (October 2006, Cape Town, South Africa). For a complete listing of participating members of PACORES see the Appendix. The authors have no financial interests in the subject matter presented.     

Treatment of neovascular age-related macular degeneration with pegaptanib and boosting with bevacizumab or ranibizumab as needed

BACKGROUND AND OBJECTIVE: Neovascular age-related macular degeneration presents a therapeutic challenge. The efficacy of pegaptanib sodium, a selective inhibitor of vascular endothelial growth factor 165, was examined as a therapeutic mainstay combined with "as needed" boosts of nonselective vascular endothelial growth factor blockade with bevacizumab or ranibizumab. PATIENTS AND METHODS: A retrospective chart review of outcomes of patients treated with pegaptanib and later boosted with bevacizumab or ranibizumab was conducted. Visual acuity, optical coherence tomography, and fluorescein angiography findings were recorded and assessed. RESULTS: During a mean follow-up of 12.1 months, an average of 7.8 injections of pegaptanib 0.3 mg, 1.4 injections of bevacizumab 1.25 mg, and 0.9 injections of ranibizumab 0.5 mg were administered to 17 eyes. In all, 47% of eyes gained 3 or more lines of visual acuity and 76% gained 0 or more lines. CONCLUSION: Pegaptanib as a mainstay of neovascular age-related macular degeneration therapy with an occasional boost of bevacizumab or ranibizumab appears to be an effective treatment option.     

Quality of life in patients with age-related macular degeneration: results from the VISION study

PURPOSE: To assess the impact of treatment with pegaptanib sodium vsusual care on vision-related quality of life (VRQoL) in patients with age-related macular degeneration (AMD). METHODS: VRQoL was a secondary end point in the trial, a prospective, randomized, double-masked, multicentre, dose-ranging study. Three doses of pegaptanib (0.3, 1, and 3 mg) were compared with usual care with respect to changes in VRQoL as indicated by the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ 25), administered at baseline and weeks 30 and 54. Four of the NEI-VFQ 25 domains were prospectively designated as primary: near vision, distance vision, role limitations, and dependency. Between-group differences were assessed using an analysis of covariance model with age, gender, and baseline score as covariates. RESULTS: NEI-VFQ 25 data were available for 569 subjects. At week 54, improvements in the distance vision and role limitations domains were greater in pegaptanib than usual care arms. No substantial increase in ocular pain was noted in pegaptanib-treated patients. No clear superiority of any particular dosage strength of pegaptanib was demonstrated, and no significant differences or trends favoured usual care on any domain score or the NEI-VFQ 25 composite score. The greatest VRQoL benefit was seen in responders (lost<3 lines) to treatment. CONCLUSION: The VISION trial provided evidence of trends in quality-of-life benefit associated with effective treatment of AMD using pegaptanib. Treatment with pegaptanib is expected to contribute significantly to VRQoL improvement for responder patients.