Systemic safety of intravitreal anti-vascular endothelial growth factor agents in age-related macular degeneration

A prospective observation of influence of anti-VEGF on optic disc vasculature in nAMD patients

BACKGROUND

This study aims to investigate the short-term changes in relatively normal retinal vessels following anti-vascular endothelial growth factor (anti-VEGF) therapy in nAMD patients, an area that currently represents a research gap.

METHODS

In this prospective study, we enrolled patients newly diagnosed with neovascular age-related macular degeneration (nAMD) and received standardized monthly anti-VEGF therapy for three months. Follow-ups were conducted at baseline and 1-week, 1-month, 2-months and 3-months post first injection. Assessment indicators included radial peripapillary capillary vascular density (RPC-VD) and retinal nerve fiber layer (RNFL) thickness in different optic disk regions using optical coherence tomography angiography, as well as intraocular pressure (IOP).

RESULTS

68 nAMD patients (68 eyes) were included in this study. Significant reductions of RPC-VD and increases of RNFL thickness primarily in the nasal regions were observed 1-week post anti-VEGF (adjusted P < 0.05). Significant negative correlations were found between 1-week changes in RPC-VD and RNFL thickness in the nasal sectors (P < 0.05). From 1 to 3 months post-injection, RPC-VD and RNFL thickness essentially returned to baseline levels. Throughout the follow-up periods, IOP remained stable (P > 0.05).

CONCLUSION

Anti-VEGF treatments transiently influence the relatively normal retinal vessels, which might lead to nerve fiber edema, predominantly on the nasal side of the optic disk.

Risk analysis for patients with arterial thromboembolic events after intravitreal ranibizumab or aflibercept injections

Intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents have been increasingly applied in the treatment of retinal neovascular diseases. Concerns have arisen that these intravitreal agents may be associated with a potential risk of arterial thromboembolic (ATE) events. We conducted a retrospective, nationwide population-based cohort study to analyze the risks for ATE events in patients receiving intravitreal ranibizumab (IVR) or intravitreal aflibercept (IVA). Data (2011-2018) were obtained from Taiwan's National Health Insurance Research Database. Cox proportional-hazards model was used to identify the risk factors for ATEs. Of the total 3,469 patients, 1393 and 2076 patients received IVR and IVA, respectively. In our result, 38 ATEs occurred within 6 months after IVR or IVA. The risk of ATEs was lower in patients receiving IVR than in those receiving IVA (adjusted hazard ratio [aHR], 0.27; 95% confidence interval [CI], 0.11-0.66). Patients with coronary artery disease (CAD) exhibited a higher risk of ATEs than did those without CAD (aHR, 3.47; 95% CI, 1.41-8.53). The risk of ATEs was higher in patients with an event of acute myocardial infarction (AMI) or ischemic stroke (IS) within 6 months prior to index IVI than in those without recent AMI/IS events (aHR, 23.8; 95% CI, 7.35-77.2 and IS: aHR, 290.2; 95% CI, 103.1-816.4). In conclusion, compared with IVA, IVR was associated with a lower risk of ATEs. When strategies for anti-VEGF agents are devised, risk factors, such as CAD and a history of AMI or IS within 6 months should be considered. Further large-scale studies are warranted to elucidate the safety of anti-VEGF injections.

Anti-VEGF Drugs Dynamics: Relevance for Clinical Practice

Background: A drug and disease assessment model was used to evaluate the impact of different treatment regimens on intravitreal ranibizumab, bevacizumab, aflibercept, and brolucizumab concentrations and the proportion of free vascular endothelial growth factor (VEGF) to total VEGF. Methods: A time-dependent mathematical model using Wolfram Mathematica software was used. The pharmacokinetic and pharmacodynamic data for anti-VEGFs were obtained from published reports. The model simulated drug concentration after single and multiple doses of ranibizumab, bevacizumab, aflibercept, and brolucizumab, and it extrapolated time-dependent intraocular free VEGF proportion values. Various fixed treatment regimens (q4, q8, q10, q12) were simulated and evaluated as candidates for clinical utilization. Results: Our mathematical model shows good correlation between intraocular VEGF proportion values and clinical data. Simulations suggest that each anti-VEGF agent would allow for distinct treatment intervals to keep the proportion of free VEGF under threshold levels. Regimens scheduling q8 ranibizumab, q8 bevacizumab, q12 aflibercept, and q10 brolucizumab administration permit to maintain the proportion of unbound VEGF below 0.001%. Conclusions: Fixed q8 ranibizumab, q8 bevacizumab, q12 aflibercept, or q10 brolucizumab regimens may produce adequate intraocular VEGF inhibition.

Drug-related adverse effects of antivascular endothelial growth factor agents

PURPOSE OF REVIEW

Antivascular endothelial growth factor (VEGF) agents have provided historic therapeutic breakthroughs in the treatment of retinal disease. New anti-VEGF agents are emerging for the treatment of retinal vascular diseases. Both systemic and ocular adverse effect need to be understood in managing patients. This review aims to highlight the adverse effects seen with routine use of bevacizumab, ranibizumab and aflibercept, as well as with new medications such as brolucizumab and abicipar.

RECENT FINDINGS

We review the recent findings of intraocular inflammation (IOI) of brolucizumab and abicipar in the context of the efficacy and safety reported with the routine anti-VEGF agents. Specifically, brolucizumab has been reported to cause occlusive retinal vasculitis in the setting of IOI, which has not been seen in other anti-VEGF medications. In addition, abicipar appears to cause IOI at a higher rate of patients than other anti-VEGF agents have previously.

SUMMARY

Newer anti-VEGF agents pose a significant risk of adverse events not seen with routine anti-VEGF agents.

Association of Intravitreal Anti-Vascular Endothelial Growth Factor Therapy With Risk of Stroke, Myocardial Infarction, and Death in Patients With Exudative Age-Related Macular Degeneration

Importance

Current studies assessing the risk of stroke, myocardial infarction (MI), and death in patients undergoing intravitreal anti-vascular endothelial growth factor (VEGF) therapy are inconclusive. To our knowledge, no population-based studies have been performed to examine these potential risks.

Objective

To examine whether patients with exudative age-related macular degeneration (AMD) receiving intravitreal anti-VEGF injections have a higher incidence of MI, stroke, or death compared with control populations.

Design, Setting, and Participants

This population-based, retrospective cohort study included 504 patients from Olmsted County, Minnesota, identified through the Rochester Epidemiology Project (REP) database as receiving at least 1 intravitreal anti-VEGF injection for exudative AMD from January 1, 2004, to December 31, 2013. Three age- and sex-matched control groups of individuals who did not receive anti-VEGF treatment and were derived from the REP database were also studied: control individuals with exudative AMD in the era before anti-VEGF (January 1, 1990, to December 31, 2003), controls with dry AMD, and controls without AMD. Data analysis was performed from September 1, 2016, to September 1, 2017.

Main Outcomes and Measures

Five-year risk of stroke, MI, and death were assessed in patients compared with controls using Kaplan-Meier and multivariate analysis with Cox proportional hazards regression models.

Results

The study included 504 patients (321 female [63.7%]; mean [SD] age, 76.5 [10.0] years) who received at least 1 intravitreal anti-VEGF injection for exudative AMD during the study period. Kaplan-Meier analysis revealed a 5-year risk of 7.2% for stroke, 6.1% for MI, and 30.0% for death. Patients who received anti-VEGF had no increased risk of stroke or MI compared with controls with dry AMD (n = 504), controls with exudative AMD (n = 473), or controls without AMD (n = 504). There was an increased risk of mortality compared with controls with exudative AMD in the era prior to anti-VEGF therapy but not the other control groups on multivariate analysis (hazard ratio, 1.63; 95% CI, 1.30-2.04; P < .001).

Conclusions and Relevance

This population-based study revealed that intravitreal anti-VEGF therapy for exudative AMD was not associated with consistent increases in the risk of stroke, MI, or death compared with no therapy in patients with or without AMD. It appears to be likely the cardiac events these patients experience are not attributable to their anti-VEGF therapy.

Effect of intravitreal injection of aflibercept on blood coagulation parameters in patients with age-related macular degeneration

Purpose:

Treatment with intravitreal injections of anti-vascular endothelial growth factor agents has been associated with an increased risk of arterial thromboembolic events. The aim of the present pilot study was to assess the effect of a single intravitreal injection of aflibercept on coagulation.

Methods:

Treatment-naïve patients with age-related macular degeneration (n = 47), who were scheduled to undergo treatment with intravitreal injections of aflibercept, were enrolled. None of the included patients received any anticoagulation therapy or had a history of a recent arterial thromboembolic event. Blood samples were collected before the first intravitreal injection, and at 7 and 30 days after aflibercept administration. We evaluated coagulation parameters, such as platelet count and plasma fibrinogen and D-dimer levels; functional clotting parameters, such as prothrombin time, international normalized ratio, and activated partial thromboplastin time; and anticoagulant parameters, such as the levels of Proteins S and C.

Results:

The levels of all of the evaluated biomarkers were within the normal range at baseline and at both the time points throughout the study. No statistically significant changes were observed in any of the measured parameters at 1 week and 1 month after aflibercept administration.

Conclusion:

A single intravitreal injection of aflibercept in treatment-naïve patients with exudative age-related macular degeneration has no statistically significant effect on blood coagulation parameters for up to 1 month after aflibercept administration. Our results also provide an explorative statistical data, and further studies are required to evaluate any significant clinical effects of aflibercept on blood coagulation parameters.

ClinicalTrials.gov ID:

NCT03509623.

Necrotizing enterocolitis after intravitreal bevacizumab in an infant with Incontinentia Pigmenti - a case report

Background

Incontinentia Pigmenti is a rare disease affecting multiple organs. Fifty of patients show affection of the eye with retinopathy and possible amaurosis being the worst outcome. Treatment has commonly been panretinal laser coagulation but intravitreal application of bevacizumab as VEGF-inhibitor has shown to effectively suppress retinal neovascularization.

Case presentation

A six-week-old female infant with Incontinentia Pigmenti developed a foudroyant necrotizing enterocolitis shortly after intravitreal injection of bevazicumab due to a retinopathy with impending tractional detachment of the left eye. Since the onset of abdominal symptoms occurred immediately after the intravitreal application, a link between the two events seemed likely. Sequential analyses of the VEGF serum concentrations showed a massive suppression of endogenous VEGF with only a very slow recovery over weeks. Such a severe systemic adverse event has not been reported after intravitreal treatment with bevacizumab in an infant.

Conclusion

This case report shows a relevant systemic uptake of bevacizumab after intravitreal application as suppressed VEGF levels show. There seems to be a connection between suppressed VEGF levels and the onset of necrotizing enterocolitis. Therefore, treatment with bevacizumab should be carefully considered and further research is needed to assess this drug’s safety profile.

Pharmacokinetics of Intravitreal Anti-VEGF Drugs in Age-Related Macular Degeneration

Intravitreal administration of anti-vascular endothelial growth factor (VEGF) antibodies has become the standard treatment for Age-Related Macular Degeneration; however, the knowledge of their pharmacokinetics is limited. A comprehensive review of the preclinical and clinical pharmacokinetic data that were obtained in different studies with intravitreal bevacizumab, ranibizumab, and aflibercept has been conducted. Moreover, the factors that can influence the vitreous pharmacokinetics of these drugs, as well as the methods that were used in the studies for analytical determination, have been exposed. These anti-VEGF drugs present different charge and molecular weights, which play an important role in vitreous distribution and elimination. The pharmacokinetic parameters that were collected differ depending on the species that were involved in the studies and on physiological and pathological conditions, such as vitrectomy and lensectomy. Knowledge of the intravitreal pharmacokinetics of the anti-VEGF drugs that were used in clinical practice is of vital importance.

Intravitreal bevacizumab treatment for neovascular age-related macular degeneration and thromboembolic events

BACKGROUND

Systemic complications of intravitreal anti-vascular endothelial growth factor agents are relatively uncommon but highly significant.

OBJECTIVES

Primary objective: To assess the risk for thromboembolic events following intravitreal bevacizumab injection in neovascular age-related macular degeneration patients by a large population-based study. Secondary objective: To analyze the association between injection frequency and the risk for thromboembolic events, the time interval between the injection and the thromboembolic events, and the influence of chronic diseases on complications rate.

DESIGN

A retrospective cohort study.

METHODS

Consecutive neovascular age-related macular degeneration patients receiving intravitreal bevacizumab at Soroka University Medical Center from December 2005 to December 2013 were included. Thromboembolic events analyzed included acute coronary syndrome, acute myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism. The thromboembolic event rate was compared 2 years prior and 2 years after the initial intravitreal bevacizumab injection.

RESULTS

A total of 2102 patients were included. Acute coronary syndrome and stroke rate were higher 2 years after intravitreal bevacizumab (p = 0.03 and p = 0.01, respectively). No statistical significant difference was found for the rest of thromboembolic events. Patients older than 80 years and patients receiving less than six intravitreal bevacizumab injections were more likely to experience stroke. Patients with known cardiovascular risk factors before starting injections did not develop significant more thromboembolic events.

CONCLUSION

In our study population, patients treated with intravitreal bevacizumab were significantly more likely to experience stroke during 2 years after first injection.

3D endothelial cell spheroid/human vitreous humor assay for the characterization of anti-angiogenic inhibitors for the treatment of proliferative diabetic retinopathy

Proliferative diabetic retinopathy (PDR) represents a main cause of acquired blindness. Despite the recognition of the key role exerted by vascular endothelial growth factor (VEGF) in the pathogenesis of PDR, limitations to anti-VEGF therapies do exist. Thus, rapid and cost-effective angiogenesis assays are crucial for the screening of anti-angiogenic drug candidates for PDR therapy. In this context, evaluation of the angiogenic potential of PDR vitreous fluid may represent a valuable tool for preclinical assessment of angiostatic molecules. Here, vitreous fluid obtained from PDR patients after pars plana vitrectomy was used as a pro-angiogenic stimulus in a 3D endothelial cell spheroid/human vitreous assay. The results show that PDR vitreous is able to stimulate the sprouting of fibrin-embedded HUVEC spheroids in a time- and dose-dependent manner. A remarkable variability was observed among 40 individual vitreous fluid samples in terms of sprouting-inducing activity that was related, at least in part, to defined clinical features of the PDR patient. This activity was hampered by various extracellular and intracellular signaling pathway inhibitors, including the VEGF antagonist ranibizumab. When tested on 20 individual vitreous fluid samples, the inhibitory activity of ranibizumab ranged between 0 and 100% of the activity measured in the absence of the drug, reflecting a variable contribution of angiogenic mediators distinct from VEGF. In conclusion, the 3D endothelial cell spheroid/human vitreous assay represents a rapid and cost-effective experimental procedure suitable for the evaluation of the anti-angiogenic activity of novel extracellular and intracellular drug candidates, with possible implications for the therapy of PDR.

Introducing Anti-Vascular Endothelial Growth Factor Therapies for AMD Did Not Raise Risk of Myocardial Infarction, Stroke, and Death

PURPOSE

To assess the effect of availability of anti-vascular endothelial growth factor (VEGF) therapy on mortality and hospitalizations for acute myocardial infarction (AMI) and stroke over a 5-year follow-up period in United States Medicare beneficiaries newly diagnosed with exudative age-related macular degeneration (AMD) in 2006 compared with control groups consisting of beneficiaries (1) newly diagnosed with exudative AMD at a time when anti-VEGF therapy was not possible and (2) newly diagnosed with nonexudative AMD.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Beneficiaries newly diagnosed with exudative and nonexudative AMD in 2000 and 2006 selected from a random longitudinal sample of Medicare 5% claims and enrollment files.

METHODS

Beneficiaries with a first diagnosis of exudative AMD in 2006 were the treatment group; beneficiaries newly diagnosed with exudative AMD in 2000 or nonexudative AMD in 2000 or 2006 were control groups. To deal with potential selection bias, we designed an intent-to-treat study, which controlled for nonadherence to prescribed regimens. The treatment group consisted of patients with clinically appropriate characteristics to receive anti-VEGF injections given that the therapy is available, bypassing the need to monitor whether treatment was actually received. Control groups consisted of patients with clinically appropriate characteristics but first diagnosed at a time when the therapy was unavailable (2000) and similar patients but for whom the therapy was not clinically indicated (2000, 2006). We used a Cox proportional hazard model.

MAIN OUTCOME MEASURES

All-cause mortality and hospitalization for AMI and stroke during follow-up.

RESULTS

No statistically significant changes in probabilities of death and hospitalizations for AMI and stroke within a 5-year follow-up period were identified in exudative AMD beneficiaries newly diagnosed in 2006, the beginning of widespread anti-VEGF use, compared with 2000. As an alternative to our main analysis, which excluded beneficiaries from nonexudative AMD group who received anti-VEGF therapies during follow-up, we performed a sensitivity analysis with this group of individuals reincluded (11% of beneficiaries newly diagnosed with nonexudative AMD in 2006). Results were similar.

CONCLUSIONS

Introduction of anti-VEGF agents in 2006 for treating exudative AMD has not posed a threat of increased risk of AMI, stroke, or all-cause mortality.