Intravitreal Bevacizumab and Cardiovascular Risk in Patients with Age-Related Macular Degeneration: Systematic Review and Meta-Analysis of Randomized Controlled Trials and Observational Studies

Ganglion Cell Layer Thickness Change in Neovascular Age-Related Macular Degeneration Treated With Anti-VEGF Injections

Purpose:

This work assesses bilateral ganglion cell layer–inner plexiform layer (GCL-IPL) thickness changes in patients with unilateral neovascular age-related macular degeneration (nAMD) treated with antivascular endothelial growth factor (anti-VEGF).

Methods:

In this single-center, retrospective, cohort study, the medical records of patients with unilateral nAMD treated with anti-VEGF were reviewed. The treated group included eyes with newly diagnosed nAMD that subsequently underwent treatment with intravitreal anti-VEGF injections. The control group was the fellow eye with dry AMD. Eyes receiving at least 10 intravitreal injections were included. Measurement of GCL-IPL thickness was performed at different time points using spectral domain–optical coherence tomography.

Results:

A total of 216 eyes of 108 patients met the inclusion criteria. The mean age ± SD was 80.1 ± 10.7 years. Eyes in the treated group underwent a mean ± SD of 20.2 ± 7.2 injections in 21.3 ± 6.8 months. At baseline, average mean ± SD of GCL-IPL thickness was 73.71 ± 8.81 µm and 73.84 ± 8.26 µm in the treated and fellow eye, respectively ( P = .795). After 10 injections the average thickness was 65.41 ± 14.08 µm and 68.77 ± 13.24 µm in the treated and fellow eye, respectively ( P = .007). The absolute decrease in thickness was significantly greater in the treated eye than the fellow eye (mean ± SD, 8.31 ± 11.19 µm vs 5.07 ± 10.83 µm, respectively; P = .002).

Conclusions:

GCL-IPL thickness decreased significantly in the treated group more than in the control group after 10 anti-VEGF injections. The mechanism and clinical significance of this observation warrants further study.

Clinical Efficacy and Safety of Angiogenesis Inhibitors: Sex Differences and Current Challenges

Vasoactive molecules, such as vascular endothelial growth factor (VEGF) and endothelins, share cytokine-like activities and regulate endothelial cell (EC) growth, migration and inflammation. Some endothelial mediators and their receptors are targets for currently approved angiogenesis inhibitors, drugs that are either monoclonal antibodies raised towards VEGF, or inhibitors of vascular receptor protein kinases and signaling pathways. Pharmacological interference with the protective functions of ECs results in a similar spectrum of adverse effects. Clinically, the most common side effects of VEGF signaling pathway inhibition include an increase in arterial pressure, left ventricular (LV) dysfunction ultimately causing heart failure, and thromboembolic events, including pulmonary embolism, stroke, and myocardial infarction. Sex steroids such as androgens, progestins, and estrogen and their receptors (ERα, ERβ, GPER; PR-A, PR-B; AR) have been identified as important modifiers of angiogenesis, and sex differences have been reported for anti-angiogenic drugs. This review article discusses the current challenges clinicians are facing with regard to angiogenesis inhibitor treatments, including the need to consider sex differences affecting clinical efficacy and safety. We also propose areas for future research taking into account the role of sex hormone receptors and sex chromosomes. Development of new sex-specific drugs with improved target and cell-type selectivity likely will open the way personalized medicine in men and women requiring antiangiogenic therapy and result in reduced adverse effects and improved therapeutic efficacy.

Complement factor B knockdown by short hairpin RNA inhibits laser-induced choroidal neovascularization in rats

AIM

To evaluate whether recombinant complement factor B (CFB) short hairpin RNA (shRNA) reduces laser-induced choroidal neovascularization (CNV) in rats.

METHODS

Laser-induced rat CNV model was established, and then the animals underwent fundus fluorescence angiography (FFA) and hematoxylin and eosin (HE) staining. On day 3 and 7 after photocoagulation, the expression of CFB and membrane attack complex (MAC) was detected by immunhischemistry. A recombinant CFB-shRNA plasmid was constructed. CFB and scrambled shRNA plasmids were intravenous injected into rats via the tail vein on the day of laser treatment, respectively. On day 7, the incidence of CNV was determined by FFA, and the expression of CFB and vascular endothelial growth factor (VEGF) in retinal pigment epithelium (RPE)/choroidal tissues was detected by immunhischemistry, Western blot and/or semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) in CFB and scrambled shRNA groups. The possible adverse effects of CFB-shRNA injection were assessed by transmission electron microscopy and electroretinography.

RESULTS

FFA and HE results indicated that a laser-induced rat CNV model was successfully established on day 7 after photocoagulation. The expression of CFB and MAC was extremely weak in normal retina and choroid, and increased on day 3 after photocoagulation. However, it started to reduce on day 7. CFB shRNA plasmid was successfully constructed and induced CFB knockdown in the retinal and choroidal tissues. FFA showed CFB knockdown significantly inhibited incidence of CNV in rats. Moreover, CFB knockdown significantly inhibited the expression of VEGF in RPE/choroidal tissues. CFB shRNA caused no obvious side effects in eyes.

CONCLUSION

CFB knockdown significantly inhibits the formation and development of CNV in vivo through reducing the expression of VEGF, which is a potential therapy target. The alternative pathway of complement activation plays an important role in CNV formation.

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.

Change in cardiac troponin T level after intravitreal anti-vascular endothelial growth factor treatment: Prospective pilot study

Background:

Evaluate subclinical myocardial injury associated with intravitreal anti-vascular endothelial growth factor therapy by measuring serum high-sensitivity cardiac troponin T.

Methods:

This is a prospective pilot comparative study conducted at American University of Beirut Medical Center, Beirut, Lebanon. In total, 40 consecutive patients were randomized to receive either intravitreal bevacizumab or ranibizumab. Patients received three consecutive monthly injections of the assigned drug, then continued treatment as needed. Systemic concentrations of high-sensitivity cardiac troponin T and vascular endothelial growth factor were obtained at baseline, week 9, and week 24. Primary endpoint measure was change in high-sensitivity cardiac troponin T levels compared to baseline. Secondary endpoint measure was change in systemic vascular endothelial growth factor levels.

Results:

There was no significant difference in high-sensitivity cardiac troponin T levels over time ( p = 0.227) within each treatment group and no significant difference between treatments at any time point ( p = 0.276). There was a significant decrease in plasma vascular endothelial growth factor levels at week 9 ( p = 0.001) and week 24 ( p < 0.001) compared to baseline. In the ranibizumab group, vascular endothelial growth factor levels were not significantly different at weeks 9 and 24 compared to baseline ( p = 0.708 and p = 0.117, respectively). There was a significant association between the number of bevacizumab injections from weeks 8 to 24 and the decrease in vascular endothelial growth factor levels at week 24 ( R = −0.67, p = 0.032). This correlation was not observed in the ranibizumab group ( R = −0.341, p = 0.141).

Conclusion:

Repeated intravitreal bevacizumab or ranibizumab did not influence serum high-sensitivity cardiac troponin levels. Intravitreal bevacizumab but not ranibizumab lowered free-systemic vascular endothelial growth factor levels, which was observed in this study to be inversely related to the number of bevacizumab injections.

Appraising the Quality of Systematic Reviews for Age-Related Macular Degeneration Interventions: A Systematic Review

Importance

Age-related macular degeneration (AMD) is a leading cause of vision impairment. It is imperative that AMD care is timely, appropriate, and evidence-based. It is thus essential that AMD systematic reviews are robust; however, little is known about the quality of this literature.

Objectives

To investigate the methodological quality of systematic reviews of AMD intervention studies, and to evaluate their use for guiding evidence-based care.

Evidence Review

This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. All studies that self-identified as a systematic review in their title or abstract or were categorized as a systematic review from a medical subject heading and investigated the safety, efficacy and/or effectiveness of an AMD intervention were included. Comprehensive electronic searches were performed in Ovid MEDLINE, Embase, and the Cochrane Library from inception to March 2017. Two reviewers independently assessed titles and abstracts, then full-texts for eligibility. Quality was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool. Study characteristics (publication year, type of intervention, journal, citation rate, and funding source) were extracted.

Findings

Of 983 citations retrieved, 71 studies (7.6%) were deemed eligible. The first systematic review relating to an AMD intervention was published in 2003. More than half were published since 2014. Methodological quality was highly variable. The mean (SD) AMSTAR score was 5.8 (3.2) of 11.0, with no significant improvement over time (r = -0.03; 95% CI, -0.26 to 0.21; P = .83). Cochrane systematic reviews were overall of higher quality than reviews in other journals (mean [SD] AMSTAR score, 9.9 [1.2], n = 15 vs 4.7 [2.2], n = 56; P < .001). Overall, there was poor adherence to referring to an a priori design (22 articles [31%]) and reporting conflicts of interest in both the review and included studies (16 articles [23%]). Reviews funded by government grants and/or institutions were generally of higher quality than industry-sponsored reviews or where the funding source was not reported.

Conclusions and Relevance

There are gaps in the conduct of systematic reviews in the field of AMD. Enhanced endorsement of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement by refereed journals may improve review quality and improve the dissemination of reliable evidence relating to AMD interventions to clinicians.

Overview of the Safety of Anti-VEGF Drugs: Analysis of the Italian Spontaneous Reporting System

INTRODUCTION

Anti-vascular endothelial growth factor (anti-VEGF) drugs are widely used for the treatment of several cancers and retinal diseases. The systemic use of anti-VEGF drugs has been associated with an increased risk of serious adverse reactions. Whether this risk is also related to intravitreal administration of anti-VEGF drugs is unclear.

OBJECTIVE

The aim of this study was to provide an overview of the safety of anti-VEGF drugs in oncology and ophthalmology settings using the Italian Spontaneous Reporting System (SRS).

METHODS

We selected all suspected adverse drug reaction (ADR) reports attributed to anti-VEGF drugs and conducted descriptive frequency analyses stratified by indication of use. As a measure of disproportionality, we calculated the proportional reporting ratio with 95% confidence intervals at the level of standardized Medical Dictionary for Regulatory Activities (MedDRA^®) queries (SMQs).

RESULTS

Of a total of 2472 anti-VEGF drug-related reports, 2173 (87.9%) and 299 (12.1%) were attributed to systemic and intravitreal use of these drugs, respectively. The frequency of serious ADRs reported was higher for intravitreal administration of anti-VEGF drugs than for systemic use in patients with cancer (58.9 vs. 34.1%) (p < 0.001) and were disproportionally associated with ischemic heart disease and thromboembolic and cerebrovascular events. Most serious ADRs related to anti-VEGF drugs in patients with cancer are known and clinically relevant (e.g., gastrointestinal and vascular disorders).

CONCLUSIONS

This study documented that serious ADRs and systemic toxicity may occur not only with systemic use of anti-VEGF drugs in patients with cancer but also with intravitreal administration. Close monitoring of cardio/cerebrovascular adverse events should be considered during treatment with all anti-VEGF drugs.

The association between myocardial infarction and intravitreal bevacizumab injection

To evaluate the risk of myocardial infarction (MI) after receiving intravitreal bevacizumab (IVB) injection. We retrospectively reviewed the charts of patients who had received IVB injection in 2016, and grouped them according to whether they received the injection for age-related macular degeneration (AMD), diabetes-related complications, or retinal vein occlusion (RVO). We then investigated the prevalence of MI within 2 months after IVB injection and analyzed the possible association of IVB with MI. During 2016, 724 patients were enrolled and received a total of 1870 IVB injections. Seven patients were diagnosed with MI within 2 months after receiving an IVB injection. Of 274 patients with AMD, 2 were diagnosed with MI; of 311 patients with diabetes-related complications, 3 were diagnosed with MI; and of 139 patients with RVO, 2 were diagnosed with MI (P = 0.785). All MIs occurred between 3 days and 3 weeks after IVB injection (mean = 14.00 ± 6.45 days). The MIs after receiving IVB were associated with previous history of MI or cerebrovascular infarction in multivariate logistic regression analysis (P = 0.005). There was no significant difference in MI prevalence after IVB injection according to the reason for receiving the injection. However, care should be taken when administering IVB injections, especially to patients with risk factors such as history of MI or cerebrovascular infarction.

A Proximity Extension Assay (PEA)-based method for quantification of bevacizumab

INTRODUCTION

Proximity Extension Assay (PEA) is a direct one-step protein quantification method using a pair of DNA oligonucleotides linked to antibodies against the target molecule. It requires polyclonal or two monoclonal antibodies (mAbs) that bind to target epitopes close enough to form a DNA duplex which is quantified by real-time PCR. Bevacizumab, an anti-cancer drug, is a mAb against vascular endothelial growth factor with common cardiovascular adverse effects. It is widely used off-label to treat neovascular eye disorders by intravitreal application of small doses. Even then, certain amount reaches systemic circulation which is considered relevant regarding safety. We aimed to set-up a PEA-based assay for bevacizumab in human plasma and to preliminary evaluate it in patients treated intravitreally.

METHODS

We tested (PEA, quantitative PCR) several combinations of commercial mAbs and a Fab fragment against bevacizumab. The best combination was used to quantify bevacizumab in three patients donating plasma before and 24 h after the first intravitreal injection.

RESULTS

A combination of a mAb and a Fab fragment (HCA184 and HCA182, Bio-Rad Laboratories, Inc.) performed best: standard curve R² 0.98, linear dynamic range 1-1000 pM, lower limit of quantification 1 pM (149 pg/mL) and a satisfactory precision (coefficient of variation 12%). All pre-dose patient concentrations were zero, while post-dose concentrations were 10.94, 13.73 and 55.49 ng/mL, in line with previous reports.

DISCUSSION

This is the first set-up of a PEA-based assay for quantification of bevacizumab in human plasma. Its good performance and high sensitivity support further evaluation for potential uses particularly when the expected concentrations are low.

Mortality associated with bevacizumab intravitreal injections in age-related macular degeneration patients after acute myocardial infarct: a retrospective population-based survival analysis

BACKGROUND

Intraocular injections of antivascular endothelial growth factor (VEGF) agents are currently the main therapy in age-related macular degeneration (AMD). The safety of bevacizumab, an anti-VEGF compound frequently delivered off label, is debated, particularly for high-group risks. We aim to analyze the mortality associated with intravitreal injections of bevacizumab for AMD in patients previously diagnosed with acute myocardial infarct (MI).

METHODS

In a national database, we identified bevacizumab-treated AMD patients with a diagnosis of MI prior to their first bevacizumab injection, delivered between September 2008 and October 2014 (n = 2100). We then generated sub-groups of patients treated within 3 months (n = 11), 6 months (n = 24), 12 months (n = 52), and 24 months (n = 124) after MI. Those patients were compared to age- and gender-matched members that had a MI at the same time and had never been exposed to anti-VEGF. Survival analysis was performed using propensity score-adjusted Cox regression.

RESULTS

Bevacizumab-treated patients were slightly and insignificantly older than controls (mean age 83.25 vs 83.19 year, P = .75). Gender distribution was similar. In a Cox regression adjusted with propensity score, the following differences in mortality were found: within 3 months between MI and initiation of bevacizumab treatment, OR = 6.22 (95% C.I 1.08-35.97, P < .05); within 6 months, OR = 2.37 (95% C.I 0.93-6.02, P = .071); within 12 months, OR = 3.00 (95% C.I 1.44-6.28, P < .01); within 24 months after MI, OR = 2.24 (95% C.I 1.35-3.70, P < .01); and MI any time prior to first bevacizumab injection, OR = 1.71 (95% C.I 1.53-1.92, P < .001).

CONCLUSIONS

We report increased mortality associated with the use of intravitreal bevacizumab in AMD patients after MI, compared to age- and gender-matched post-MI patients with no exposure to any anti-VEGF agent. Caution should be taken while offering bevacizumab to AMD patients after MI.

Ranibizumab and digital ischemia

Case report of a patient with age-related macular degeneration whose digital ischemia can most plausibly be attributed to ranibizumab.

PURPOSE

To report ranibizumab as the probable cause of digital ischemia in a patient treated for age-related macular degeneration.

METHODS

Single-patient case report.

RESULTS

An 83-year-old woman with an unremarkable medical history suffered acute ischemia in her left hand with necrosis of the distal phalange of the fifth finger after six intravitreal injections of ranibizumab. Her etiological work-up was negative. Her condition improved after endovascular revascularization and remained good at six months' follow-up after three months of dual antithrombotic therapy (low molecular weight heparin then rivaroxaban, both with aspirin) followed by rivaroxaban alone and four courses of intravenous iloprost.

CONCLUSION

The increased incidence of peripheral arterial thromboembolic events in patients under ranibizumab treatment is slight but significant, with 0.8-5% of patients affected, most of which suffer strokes. These events seem to occur at a random time after ranibizumab treatment is initiated and no reliable marker has yet been identified. The most probable cause of digital ischemia in our patient was ranibizumab.

Geographic and Demographic Variation in Use of Ranibizumab Versus Bevacizumab for Neovascular Age-related Macular Degeneration in the United States

PURPOSE

To examine demographic and geographic variation in the use of ranibizumab and bevacizumab for the treatment of neovascular age-related macular degeneration (AMD) among Medicare beneficiaries.

DESIGN

Retrospective cohort study.

METHODS

Using a 100% sample of Medicare claims data, we evaluated Medicare beneficiaries (N = 195 812) with an index claim for neovascular AMD between July 1, 2006, and June 30, 2009, to determine whether beneficiaries first received ranibizumab or bevacizumab following initial diagnosis.

RESULTS

The overall proportion of beneficiaries that first received ranibizumab for neovascular AMD was 35%, and varied significantly (0.9%-84.6%) across the 306 US hospital referral regions (median = 33%, interquartile range = 17%-49%). Based on hierarchical logistic regression models, the likelihood of receiving ranibizumab declined over time (adjusted odds ratio (aOR) comparing treatment in 2009 vs 2006 = 0.39, P < .001). After we controlled for year of treatment, black beneficiaries were 45% less likely to receive ranibizumab compared to non-blacks (P < .0001). Beneficiaries residing in urban areas (aOR vs isolated rural towns = 1.12, P < .001), in zip codes with higher median incomes, and in the New England and East South Central census regions (aOR vs Pacific census region = 5.57, P < .001; aOR = 3.58, P < .001, respectively) had increased odds of receiving ranibizumab.

CONCLUSIONS

The odds of receiving bevacizumab vs ranibizumab as initial therapy for neovascular AMD among US Medicare beneficiaries varied substantially across geographic and demographic groups. Relatively fewer patients received ranibizumab for initial neovascular AMD treatment in 2009 vs 2006. Future research should study the drivers of variation in utilization of these interventions, the extent this variation indicates differential access to these agents, and whether treatment choice impacts patient outcomes.