CHANGES IN PLASMA VASCULAR ENDOTHELIAL GROWTH FACTOR LEVEL AFTER INTRAVITREAL INJECTION OF BEVACIZUMAB, AFLIBERCEPT, OR RANIBIZUMAB FOR DIABETIC MACULAR EDEMA

Adverse renal events between ranibizumab and aflibercept in patients with diabetic macular oedema in Taiwan: a comparative cohort study

AIMS

To assess and compare the risk of adverse renal events among patients with diabetic macular oedema (DME) who were treated with either intravitreal ranibizumab or aflibercept in Taiwan.

METHODS

We conducted a population-based retrospective cohort study and employed a target trial emulation framework using Taiwan's National Health Insurance Database from 2011 to 2018.Patients aged over 20 years diagnosed with DME and receiving treatment with either intravitreal aflibercept or ranibizumab were included. We applied propensity score methods to ensure balance in the baseline characteristics between the two treatment groups. The primary outcomes were the adverse renal events, specifically acute renal injury and hospitalisation due to renal events. We employed Cox proportional hazards models to estimate the HRs associated with these outcomes.

RESULTS

A total of 6330 patients receiving ranibizumab and 1258 patients receiving aflibercept were included in this study. The incidence rates of adverse renal events were 102.2 and 138.7 per 1000 person-years for ranibizumab and aflibercept, respectively. Patients treated with intravitreal aflibercept had a significantly higher risk of experiencing a composite of adverse renal events (HR: 1.42; 95% CI: 1.24 to 1.63), compared with those treated with ranibizumab, and specifically also a higher risk of acute kidney injury (HR: 1.32; 95% CI: 1.08 to 1.63) and hospitalisation due to renal events (HR: 1.43; 95% CI: 1.25 to 1.64).

CONCLUSION

In comparison to ranibizumab, the intravitreal use of aflibercept was associated with a greater risk of adverse renal events. These findings provide a solid foundation for future studies to validate these results further.

Ocular and systemic vascular endothelial growth factor ligand inhibitor use and nephrotoxicity: an update

Tumor growth is intricately linked to the process of angiogenesis, with a key role played by vascular endothelial growth factor (VEGF) and its associated signaling pathways. Notably, these pathways also play a pivotal "housekeeping" role in renal physiology. Over the past decade, the utilization of VEGF signaling inhibitors has seen a substantial rise in the treatment of diverse solid organ tumors, diabetic retinopathy, age-related macular degeneration, and various ocular diseases. However, this increased use of such agents has led to a higher frequency of encountering renal adverse effects in clinical practice. This review comprehensively addresses the incidence, pathophysiological mechanisms, and current evidence concerning renal adverse events associated with systemic and intravitreal antiangiogenic therapies targeting VEGF-A and its receptors (VEGFR) and their associated signaling pathways. Additionally, we briefly explore strategies for mitigating potential risks linked to the use of these agents and effectively managing various renal adverse events, including but not limited to hypertension, proteinuria, renal dysfunction, and electrolyte imbalances.

Advances and Perspectives in Relation to the Molecular Basis of Diabetic Retinopathy-A Review

Diabetes mellitus (DM) is a growing problem nowadays, and diabetic retinopathy (DR) is its predominant complication. Currently, DR diagnosis primarily relies on fundoscopic examination; however, novel biomarkers may facilitate that process and make it widely available. In this current review, we delve into the intricate roles of various factors and mechanisms in DR development, progression, prediction, and their association with therapeutic approaches linked to the underlying pathogenic pathways. Specifically, we focus on advanced glycation end products, vascular endothelial growth factor (VEGF), asymmetric dimethylarginine, endothelin-1, and the epigenetic regulation mediated by microRNAs (miRNAs) in the context of DR.

Current Treatments for Diabetic Macular Edema

Diabetic retinopathy is a major retinal disorder and a leading cause of blindness. Diabetic macular edema (DME) is an ocular complication in patients with diabetes, and it can impair vision significantly. DME is a disorder of the neurovascular system, and it causes obstructions of the retinal capillaries, damage of the blood vessels, and hyperpermeability due to the expression and action of vascular endothelial growth factor (VEGF). These changes result in hemorrhages and leakages of the serous components of blood that result in failures of the neurovascular units (NVUs). Persistent edema of the retina around the macula causes damage to the neural cells that constitute the NVUs resulting in diabetic neuropathy of the retina and a reduction in vision quality. The macular edema and NVU disorders can be monitored by optical coherence tomography (OCT). Neuronal cell death and axonal degeneration are irreversible, and their development can result in permanent visual loss. Treating the edema before these changes are detected in the OCT images is necessary for neuroprotection and maintenance of good vision. This review describes the effective treatments for the macular edema that are therefore neuroprotective.

The Association of Intravitreal Injections of Different Anti-Vascular Endothelial Growth Factor with Systemic Outcomes in Diabetic Patients

This retrospective cohort study aimed to assess the systemic effects of three commonly available anti-vascular endothelial growth factor intravitreal injections in patients with diabetes, using data taken from a multi-institutional database in Taiwan. Patient data were sourced from the multi-institutional Chang Gung Research Database. Participants were divided into groups based on treatment with bevacizumab, ranibizumab, or aflibercept. Baseline characteristics were matched among the groups by the inverse probability of treatment weighting. The incidence rate of outcome events was calculated as the number of events divided by 100 person-years of follow-up. The cumulative incidence function was used to estimate the incidence rate of the outcome events among groups. The incidence of ischemic stroke was higher in the ranibizumab group than the bevacizumab and aflibercept groups (1.65, 0.92, and 0.61 per 100 person-years, respectively). The incidence of major adverse lower-limb events was higher in the bevacizumab group (2.95), followed by ranibizumab (2.00) and aflibercept (0.74). Major bleeding was relatively higher in bevacizumab (12.1) compared to ranibizumab (4.3) and aflibercept (3.8). All-cause death was higher for both bevacizumab (3.26) and aflibercept (2.61) when compared to ranibizumab (0.55), and all-cause admission was found to be highest with bevacizumab (58.6), followed by aflibercept (30.2), and ranibizumab (27.6). The bevacizumab group demonstrated a greater decrease in glycated hemoglobin compared to the baseline level (-0.33%). However, a few differences in the clinical condition between the groups were still observed after matching. In conclusion, this study suggests that different anti-vascular endothelial growth factor agents may be associated with various and differing systemic adverse events. The differences might also be attributed to differences in patient characteristics and clinical status.

Wide-field swept-source OCT angiography (23 × 20 mm) for detecting retinal neovascularization in eyes with proliferative diabetic retinopathy

PURPOSE

Xephilio OCT-S1 can capture single-acquisition 23 × 20-mm wide-field swept-source optical coherence tomography angiography (SS-OCTA) images and high-resolution images using artificial intelligence. We aimed to evaluate the ability of wide-field SS-OCTA in the detection of retinal neovascularizations (NVs) in eyes with proliferative diabetic retinopathy (PDR).

METHODS

This retrospective study included 64 eyes of 36 patients (age, 57 ± 10 years; 10 female, 26 male) with PDR. All patients underwent a comprehensive ophthalmological examination, including fluorescein angiography (FA), as well as fovea- and disc-centered 23 × 20-mm OCTA imaging (A-scan/B-scan, 928/807). We compared and examined the number of NV sites identified using conventional methods (merging the findings from biomicroscopy/color fundus photography, FA) and the number of NV sites identified using vitreoretinal interface and superficial retinal slabs of wide-field SS-OCTA images, including the position of NVs (nasal upper, nasal lower, temporal upper, temporal lower, or disc).

RESULTS

We identified 168 NVs (32/40/45/35/16, in the abovementioned order) using the conventional method. Fovea-centered 23 × 20-mm OCTA images revealed 162 (96%) NVs (27/39/45/35/16). This method tended to miss nasal NV. In contrast, disc-centered 23 × 20-mm OCTA images identified nearly all NVs, detecting 166 (99%) NVs (32/40/44/34/16) in total. All NVs could be visualized using two wide-field OCTA images: fovea- and disc-centered.

CONCLUSION

Wide-field (23 × 20 mm) SS-OCTA-especially disc-centered-using Xephilio OCT-S1 identified nearly all NVs in eyes with PDR, with a single acquisition, thereby demonstrating its potential clinical application.

Intravitreal vascular endothelial growth factor inhibitors did not increase the risk of end-stage renal disease in patients with biopsy-proven diabetic kidney disease based on matched study

Purpose: This study aimed to investigate the effects of intravitreal (IVT) VEGFi on long-term renal outcomes in patients with biopsy-proven diabetic kidney disease (DKD). Patients and methods: Patients prescribed IVT VEGFi (VEGFi group) were enrolled from a retrospective cohort with biopsy-proven DKD, and those not prescribed VEGFi (non-VEGFi group) were enrolled by 1:3 propensity score matching, adjusted for clinical and pathological baseline indicators. The primary endpoint is defined as end-stage renal disease (ESRD) and the secondary endpoint is defined as all-cause mortality. Results: Compared with patients in non-VEGFi group, patients with VEGFi had a higher proportion of diabetic retinopathy (DR) (50.9% vs 100%, p < 0.001) before matching. Standardized mean difference (SMD) of age, DR, duration of diabetes, the proportion of hypertension, eGFR, initial proteinuria, serum albumin, hemoglobin, the proportion of RAAS inhibitor and interstitial fibrosis and tubular atrophy (IFTA) were >10%. After matching, there was no significant difference in clinical pathology between the two groups. Except for the proportion of hypertension, the SMD of other indicators was <10%. Endpoints such as ESRD (Log-Rank p = 0.772) and all-cause mortality (Log-Rank p = 0.834) were not significantly different between the two groups. Conclusion: Our data suggested that IVT VEGFi did not increase the incidence of ESRD and all-cause mortality in patients with DKD.

Do new drugs for diabetic macular edema offer a safer option?

INTRODUCTION

The last decade has witnessed important advances in retinal drug discovery, administered intravitreally, allowing high intraocular concentration and low systemic passage. However, local and systemic adverse events have been described and should be discussed before proposing treatment. In diabetes mellitus specifically, the choice of molecule and treatment regimen should limit the therapeutic burden, avoiding the need for frequent ophthalmological appointments, in patients receiving multi-disciplinary care.

AREAS COVERED

We aim to review and discuss the risk/benefit ratio of the main intravitreal therapies currently proposed for diabetic macular edema (DME), and how these treatments could be tailored to each individual patient.

EXPERT OPINION

Anti-VEGF injections and steroid implants are currently the two therapeutic options proposed in cases of DME. New molecules in these two classes have recently been approved and are currently being studied under phase IV observations to establish their efficacy and tolerance. The preferred therapeutic option is determined based on the ocular condition and the patient profile. As new treatments are developed, new adverse events will also enter into consideration, and retinal physicians must therefore be able to call on a range of therapeutic options and question the risk/benefit ratio of each of them before proposing a treatment.

A systematic review and meta-analysis of the effect of intravitreal VEGF inhibitors on cardiorenal outcomes

BACKGROUND

Vascular endothelial growth factor inhibitors (VEGFi) have transformed the treatment of many retinal diseases, including diabetic maculopathy. Increasing evidence supports systemic absorption of intravitreal VEGFi and development of significant cardiorenal side effects.

METHODS

Systematic review and meta-analysis (PROSPERO: CRD42020189037) of randomised controlled trials of intravitreal VEGFi treatments (bevacizumab, ranibizumab and aflibercept) for any eye disease. Outcomes of interest were cardiorenal side effects (hypertension, proteinuria, kidney function decline and heart failure). Fixed-effects meta-analyses were conducted where possible.

RESULTS

There were 78 trials (81 comparisons; 13 175 participants) that met criteria for inclusion: 47% were trials in diabetic eye disease. Hypertension (29 trials; 8570 participants) was equally common in VEGFi and control groups (7.3 versus 5.4%; RR 1.08 [0.91; 1.28]). New or worsening heart failure (10 trials; 3384 participants) had similar incidence in VEGFi and control groups (RR 1.03 [0.70; 1.51]). Proteinuria (5 trials; 1902 participants) was detectable in some VEGFi-treated participants (0.2%) but not controls (0.0%; RR 4.43 [0.49; 40.0]). Kidney function decline (9 trials; 3471 participants) was similar in VEGFi and control groups. In participants with diabetic eye disease, risk of all-cause mortality was higher in VEGFi-treated participants (RR 1.62 [1.04; 2.46]).

CONCLUSION

In trials of intravitreal VEGFi, we did not identify an increased risk of cardiorenal outcomes, though these outcomes were reported in only a minority of cases. There was an increased risk of death in VEGFi-treated participants with diabetic eye disease. Additional scrutiny of post-licensing observational data may improve recognition of safety concerns in VEGFi-treated patients.

Intravitreal Vascular Endothelial Growth Factor Inhibitor Use and Renal Function Decline in Patients with Diabetic Retinopathy

Adverse renal effects of systemic vascular endothelial growth factor (VEGF) inhibitor treatment are well documented. We aimed to identify associations between intravitreal VEGF inhibitor use and renal function decline in patients with diabetic retinopathy. We included 625 patients with diabetic retinopathy for regular renal function follow-ups and grouped them according to intravitreal therapy (67 with and 558 without treatment). We used a generalized estimating equation model to identify renal function decline risk factors. Increased age (p = 0.02), insulin use (p = 0.01), hypertension (p < 0.01), and ischemic heart disease (p < 0.01) were associated with significantly decreased estimated glomerular filtration rates (eGFRs) in patients with diabetic retinopathy after 1-year follow-up. Compared to the control group, patients who received intravitreal VEGF inhibitor injections showed a declining eGFR trend in the repeated measurement model without statistical significance (p = 0.06). In subgroup analysis, patients with initial eGFR ≤ 30 mL/min/1.73 m² who received intravitreal VEGF inhibitors had significantly decreased renal function (p < 0.01) compared to those without treatment. Intravitreal VEGF inhibitor injection was associated with renal function deterioration among patients with diabetic retinopathy and advanced chronic kidney disease. Strategies to monitor renal function after treatment should be considered in these high-risk populations.

Safety and outcomes of intravitreal aflibercept in diabetic macular edema - a systematic review

BACKGROUND

Recent evidence on the role of vascular endothelial growth factor (VEGF) in the pathogenesis of ischemia and microvascular hyperpermeability leading to macular edema has brought anti-VEGF intravitreal therapy into the limelight.

OBJECTIVE

We performed a systematic literature review focusing on the outcomes and safety of the intravitreal use of aflibercept in diabetic macular edema.

METHODS

The studies documented cases with at least three consecutive intravitreal injections of aflibercept (IVA) repeated monthly with a follow-up period of at least one year. The outcomes were evaluated in terms of reported functional and anatomical improvement of the macula, as reflected by changes in visual acuity and macular thickness measured by Optical Coherence Tomography (OCT). In addition, for safety assessment, all reported local and general adverse effects were analyzed.

RESULTS

All studies showed an overall significant anatomical and functional improvement. In patients with the 5 IVA monthly at the beginning of the therapy, the visual gain at 52 weeks varied widely between 5 and 18.9 EDRS letters, with a mean value of 9.48 letters. The higher gain was obtained in treatment naïve patients, with worse VA and increased CST at baseline. The lower gain was obtained in patients previously treated with anti-VEGF. Anti-Platelet Trialists' Collaboration-defined arterial thromboembolic events were not statistically different between the aflibercept group and the laser group.

CONCLUSIONS

Intravitreal aflibercept therapy provides significant improvement in visual acuity and a good safety profile. Randomized studies are needed to document the optimal frequency of intravitreal injections for optimal treatment.

Intravitreal vascular endothelial growth factors hypertension, proteinuria, and renal injury: a concise review

PURPOSE OF REVIEW

Nearly 20 years ago, vascular endothelial growth factor (VEGF)inhibitors (VEGFi) were adapted from systemic use from antiangiogenesis roles to intravitreal uses. Initially bevacizumab a murine immunoglobulin was injected 'off label' as a treatment for diabetic macular edema and age-related macular degeneration. Throughout the following decade aflibercept and finally ranibizumab were adapted and obtained Food and Drug Administration approval for intravitreal use. Initially systemic absorption was thought to be quite low after intravitreal injections and was quoted as being 200-fold lower than levels postulated to induce significant VEGF inhibition. Pharmacodynamic studies obtained in 2014 and again in 2017 revealed significant systemic absorption and detectable VEGF inhibition, this has since been confirmed in multiple subsequent studies.

RECENT FINDINGS

A few case reports of renal dysfunction and glomerular disease related to VEGFi were initially identified. Mixed findings on effects on blood pressure were noted in studies. More recently, 32 cases of de-novo glomerular disease and/or proteinuria exacerbation were identified. New studies have corroborated increased blood pressure, proteinuria exacerbation in patients with pre-existing nephrotic syndrome, and systemic VEGF depletion. Further, the most common lesion of systemic VEGFi nephrotoxicity, thrombotic microangiopathy, has recently been reported by our group.

SUMMARY

We will review the pharmacokinetic, translational, and epidemiological data that year upon year establish the finite-yet real risk of intravitreal VEGFi.

Review of intravitreal VEGF inhibitor toxicity and report of collapsing FSGS with TMA in a patient with age-related macular degeneration

Intravitreal vascular endothelial growth factor (VEGF) receptor blockade is used for a variety of retinal pathologies. These include age-related macular degeneration (AMD), diabetic macular edema (DME) and central retinal vein obstruction. Reports of absorption of intravitreal agents into systemic circulation have increased in number and confirmation of depletion of VEGF has been confirmed. Increasingly there are studies and case reports showing worsening hypertension, proteinuria, renal dysfunction and glomerular disease. The pathognomonic findings of systemic VEGF blockade, thrombotic microangiopathies (TMAs), are also being increasingly reported. One lesion that occurs in conjunction with TMAs that has been described is collapsing focal segmental glomerulosclerosis (cFSGS). cFSGS has been postulated to occur due to TMA-induced chronic glomerular hypoxia. In this updated review we discuss the mechanistic, pharmacological, epidemiological and clinical evidence of intravitreal VEGF toxicity. We review cases of biopsy-proven toxicity presented by our group and other investigators. We also present the third reported case of cFSGS in the setting of intravitreal VEGF blockade with a chronic TMA component that was crucially found on biopsy. This patient is a 74-year-old nondiabetic male receiving aflibercept for AMD. Of the two prior cases of cFSGS in the setting of VEGF blockade, one had AMD and the other had DME. This case solidifies the finding of cFSGS and its association with chronic TMA as a lesion that may be frequently encountered in patients receiving intravitreal VEGF inhibitors.

Intravitreal Fasudil for Treatment of Diabetic Macular Edema with an Unfavorable Response

PURPOSE

This study evaluates the effect of intravitreal injection of a Rho-associated protein kinase (ROCK) inhibitor, fasudil, on diabetic macular edema (DME) with an unfavorable response.

METHODS

This study included 14 eyes of 13 patients (mean age: 65.7 ± 5.2 years) with DME, and eligible eyes underwent single intravitreal injection of 0.025 mg fasudil. The best-corrected visual acuity (BCVA), intraocular pressure (IOP), and central macular thickness (CMT) were evaluated before and 1, 2, and 3 months after treatment. The standard automated perimetry (SAP) results and maximal response of the electroretinogram (ERG) were recorded before and 3 months after treatment.

RESULTS

The BCVA, IOP, and CMT remained unchanged during the study period. Similarly, the mean deviation obtained by SAP and each ERG parameter did not show significant changes after the treatment.

CONCLUSIONS

Although single intravitreal fasudil injection failed to show therapeutic benefits in DME, it seemed to have no negative effect on the retina.

BRAIN HEALTH ASSESSMENT IN MACULAR DEGENERATION PATIENTS UNDERGOING INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR INJECTIONS (THE BHAM STUDY): An Interim Analysis

PURPOSE

After intravitreal injection, anti-vascular endothelial growth factor (VEGF) agents are found in the systemic circulation and can suppress systemic VEGF levels. Neuronal health and cognitive function in the central nervous system have been associated with normal physiological levels of VEGF expression. We wished to determine whether there was an association between cumulative anti-VEGF exposure and cognitive function.

METHODS

One hundred and seventy-five patients aged 65 to 85 with vision of at least 20/50 or better in one eye and a diagnosis of age-related macular degeneration took an iPad-based brain health assessment to determine their risk of mild cognitive impairment. The result for each patient was compared with the total number of anti-VEGF injections per individual patient. Patients were then stratified into groups with 0 injections (control), 1 to 9 injections, 10 to 20 injections, or greater than 20 injections.

RESULTS

The group of patients with more than 20 injections had a higher likelihood of mild cognitive impairment compared with the control group, with statistically significant worse mean Z-scores (P = 0.04).

CONCLUSION

Our study is the first to associate worsening cognitive health with higher cumulative anti-VEGF injections. This study was not designed to show a causal link, but does suggest that additional investigation is warranted.

Hypertensive cerebral hemorrhage with undetectable plasma vascular endothelial growth factor levels in a patient receiving intravitreal injection of aflibercept for bilateral diabetic macular edema: a case report

Background

Intravitreal injections of anti-vascular endothelial growth factor are commonly used to treat macular diseases, including diabetic macular edema. Anti-vascular endothelial growth factor drugs can enter the systemic circulation after intravitreal injections and appear to suppress circulating vascular endothelial growth factor levels. However, whether this can cause any systemic adverse events remains unknown.

Case presentation

A 70-year-old Japanese man diagnosed with diabetic macular edema in both eyes was treated with anti-vascular endothelial growth factor intravitreal injections. One month after receiving two intravitreal injections of aflibercept 1 week apart for diabetic macular edema in both eyes, he complained of a severe acute headache. The patient was diagnosed with hypertensive cerebral hemorrhage of the occipital lobe based on an elevated blood pressure of 195/108 mmHg and the results of computed tomography and magnetic resonance imaging of his brain. The patient was treated with an intravenous injection of nicardipine hydrochloride to lower his systemic blood pressure. Two days after the stroke, the patient began oral treatment with 80 mg/day telmisartan, which was continued for 3 days, and the telmisartan dose was reduced to 40 mg/day thereafter. His blood pressure promptly dropped to 130/80 mmHg, and his severe headache disappeared. One year after the cerebrovascular stroke, the telmisartan was discontinued because his blood pressure stabilized at a normal level. His plasma vascular endothelial growth factor levels were measured via specific enzyme-linked immunosorbent assay before and after the intravitreal injections of aflibercept. Immediately before the injections, the vascular endothelial growth factor level was 28 pg/ml, but it rapidly fell below the detection limit within 1 week, where it remained for over 2 months. Two days before the cerebral hemorrhage, his plasma vascular endothelial growth factor level was below the detection limit, and 2 months later after the stroke, his plasma vascular endothelial growth factor level recovered to 41 pg/ml.

Conclusion

This case suggests that hypertension and resultant cerebral hemorrhage can occur in patients with diabetic macular edema when plasma vascular endothelial growth factor levels are systemically decreased below the detection limit for a prolonged time after local injections of anti-vascular endothelial growth factor agents into the vitreous cavity. Therefore, severely reduced plasma vascular endothelial growth factor levels could be a higher risk factor to develop generally infrequent stroke. Ophthalmologists should be aware of possible severe reduction of plasma vascular endothelial growth factor levels and resultant increase in blood pressure after intravitreal injections of an anti-vascular endothelial growth factor drug. If the plasma vascular endothelial growth factor levels could be monitored more easily and quickly during the treatment, it would help to prevent adverse events.

Systemic exposure following intravitreal administration of therapeutic agents: an integrated pharmacokinetic approach. 2. THR-687

Intravitreal (IVT) injection remains the preferred administration route of pharmacological agents intended for the treatment of back of the eye diseases such as diabetic macular edema (DME) and neovascular age-related macular degeneration (nvAMD). The procedure enables drugs to be delivered locally at high concentrations whilst limiting whole body exposure and associated risk of systemic adverse events. Nevertheless, intravitreally-delivered drugs do enter the general circulation and achieving an accurate understanding of systemic exposure is pivotal for the evaluation and development of drugs administered in the eye. We report here the full pharmacokinetic properties of THR-687, a pan RGD integrin antagonist currently in clinical development for the treatment of DME, in both rabbit and minipig. Pharmacokinetic characterization included description of vitreal elimination, of systemic pharmacokinetics, and of systemic exposure following IVT administration. For the latter, we present a novel pharmacokinetic model that assumes clear partition between the vitreous humor compartment itself where the drug is administered and the central systemic compartment. We also propose an analytical solution to the system of differential equations that represent the pharmacokinetic model, thereby allowing data analysis with standard nonlinear regression analysis. The model accurately describes circulating levels of THR-687 following IVT administration in relevant animal models, and we suggest that this approach is relevant to a range of drugs and analysis of subsequent systemic exposure.

Increased serum concentration of netrin-1 after intravitreal bevacizumab injection: is it a compensatory mechanism to counteract drug side effects?

BACKGROUND

To evaluate alterations in the serum concentrations of vascular endothelial growth factor (VEGF) and netrin-1 after intravitreal bevacizumab (BCZ) injection for the treatment of diabetic macular edema (DME).

METHODS

This prospective case-control study included a total of 50 participants assigned to one of three groups, including 10 individuals with DME and non-proliferative diabetic retinopathy (NPDR), 13 with DME, and proliferative diabetic retinopathy (PDR), and 27 healthy individuals as a control group. Serum VEGF and netrin-1 concentrations were measured by enzyme-linked immunosorbent assays (ELISAs) immediately before, as well as 1 week and 1 month after, intravitreal BCZ injection.

RESULTS

The mean VEGF serum concentrations in the PDR and NPDR groups were 388.4 and 196.9 pg/mL at baseline, respectively. After 1 week, these concentrations changed to 193.41 and 150.23 pg/mL, respectively (P = 0.001 and P = 0.005, respectively); after 1 month, the concentrations were 97.89 and 76.46 pg/mL, respectively (P = 0.001 and P = 0.009, respectively). The mean netrin-1 serum concentrations in the PDR patients and NPDR groups were 318.2 and 252.7 pg/mL at baseline, respectively. After 1 week, these concentrations increased to 476.6 and 416.3 pg/mL, respectively (P = 0.033 and P = 0.005, respectively), and after 1 month, they were 676.6 and 747.5 pg/mL, respectively (P = 0.001 and P = 0.005, respectively). The correlation analysis revealed a significant inverse relationship between changes in serum VEGF and netrin-1 concentrations in both the PDR and NPDR groups (r = - 0.685, P = 0.029).

CONCLUSIONS

Intravitreal BCZ injections work systemically to significantly decrease serum VEGF levels, leading to a significant upregulation in the concentration of another angiogenic mediator, netrin-1.

Cardiovascular Adverse Events With Intravitreal Anti-Vascular Endothelial Growth Factor Drugs: A Systematic Review and Meta-analysis of Randomized Clinical Trials

IMPORTANCE

Systemic safety of intravitreal anti-vascular endothelial growth factor (anti-VEGF) is a matter of debate and regular updates are necessary.

OBJECTIVE

To evaluate systemic adverse events (SAEs) associated with intravitreal anti-VEGF drugs compared with non-anti-VEGF treatments in patients with ocular diseases.

DATA SOURCES

Electronic searches were conducted in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases from inception to July 7, 2020.

STUDY SELECTION

Randomized clinical trials conducted in adults with retinal diseases who received intravitreal anti-VEGF drugs.

DATA EXTRACTION AND SYNTHESIS

Studies and treatment characteristics and outcome data were extracted and analyzed, and study quality was evaluated.

MAIN OUTCOMES AND MEASURES

Main outcomes were major cardiovascular events (MACEs) and total mortality. Secondary outcomes included nonocular hemorrhage, components of MACEs, other cardiovascular outcomes, serious SAEs, and all SAEs.

RESULTS

A total of 74 randomized clinical trials were analyzed: 32 trials (43%) included 14 190 patients with age-related macular degeneration (AMD), 24 (32%) included 5424 patients with diabetic retinopathy (diabetic macular edema or proliferative diabetic retinopathy), 17 trials (23%) included 3757 patients with retinal vein occlusion, and 1 trial (1%) included 122 patients with myopic choroidal neovascularization. Anti-VEGF drug administration did not increase MACEs compared with control agents (odds ratio [OR], 1.16; 95% CI, 0.85-1.58) or total mortality (OR, 1.27; 95% CI, 0.82-1.96). There was an interaction (subgroup difference, P = .04) in mortality risk depending on the underlying disease with an increase (OR, 1.80; 95% CI, 1.03-3.16; P = .04) in the risk of death in patients with diabetic retinopathy; however, no increase was observed in patients with AMD or retinal vein occlusion. Administration of anti-VEGF drugs increased the risk of nonocular hemorrhage (OR, 1.46; 95% CI, 1.01-2.10), mainly in patients with AMD.

CONCLUSIONS AND RELEVANCE

Intravitreal anti-VEGF was not associated with an increase in MACEs in the trials examined herein. Increased mortality in patients with diabetes and nonocular hemorrhages, especially in those with AMD, could represent a safety signal, but the evidence was not strong. However, continued surveillance of SAEs remains warranted.

Risk factors for fellow eye treatment in protocol T

PURPOSE

To identify risk factors for fellow eye treatment of diabetic retinopathy with Vascular Endothelial Growth Factor (VEGF) injections during the Diabetic Retinopathy Clinical Research Network (DRCR.Net) Protocol T trial METHODS: In this post-hoc analysis of randomized clinical trial data, Cox regression analysis was performed at 52 and 104 weeks to determine risk factors for treatment in 360 fellow eyes. Survival analysis was performed to determine mean time to treatment based upon medication used.

RESULTS

Of 360 fellow eyes, 142 (39.4%) required treatment between weeks 4 and 104. Risk factors predicting a lower likelihood of year 1 treatment included older subject age (Hazard Ratio [HR]=0.98, 95% CI 0.96-0.99; p = 0.02) and higher baseline study eye ETDRS score (HR=0.98, 95% CI 0.97-0.99, p = 0.04). Center-involving DME at baseline in the fellow eye was predictive of a higher treatment need at both 52 (HR=1.89, 95% CI 1.42-2.51, p < 0.0001) and 104 weeks (HR=2.68, 95% CI 1.75-4.11, p < 0.0001). Subjects treated in the study eye with aflibercept (HR=0.574, 95% CI 0.371-0.887, p = 0.013) and ranibizumab (HR=0.58, 95%CI 0.36-0.94, p = 0.03) were less likely to require first year fellow eye injection than subjects treated with bevacizumab although this difference was no longer significant at week 104 (aflibercept HR=0.77, 95% CI 0.52-1.16, p = 0.21; ranibizumab HR=0.66, 95% CI 0.43-1.00, p = 0.05). Mean time to treatment was significantly shorter in the bevacizumab group (bevacizumab 25.83 weeks, aflibercept 38.75 weeks, ranibizumab 34.70 weeks (p=0.012)).

CONCLUSION

Bilateral treatment with intravitreal anti-VEGF injections was common during the DRCR.net Protocol T. Medication choice may impact the risk of fellow eye treatment.

Treat-and-extend therapy with aflibercept for diabetic macular edema: a prospective clinical trial

PURPOSE

To investigate the efficacy and safety of a treat-and-extend (T&E) regimen using aflibercept (Eylea) for diabetic macular edema (DME).

STUDY DESIGN

Prospective, open-label, multicenter, single-arm, nonblinded clinical study.

METHODS

Forty eyes of 40 patients with DME received a T&E regimen of intravitreal aflibercept injection (IAI) with the longest treatment interval set to 16 weeks and adjunct focal/grid laser for 1 year. An intent-to-treat analysis was performed using the same last-observation-carried-forward method. A per-protocol analysis was also performed for patients who completed a 1-year T&E regimen. The primary endpoints were mean changes in best-corrected visual acuity (BCVA) and central subfield macular thickness (CST) from baseline. Secondary endpoints included IAI-interval extension and resultant IAI numbers and the association between an early response to IAI and final BCVA gain at 1 year.

RESULTS

Thirty-one patients (77.5%) completed the 1-year aflibercept T&E regimen. In these per-protocol participants, the mean CST improvement/reduction was 187.3 ± 145.0 µm (P < .001), but the mean BCVA gain was limited to 4.3 ± 12.2 letters (P = .782). Subanalysis revealed that eyes that gained ≥ 4 letters (median at week 12) after the initial 3 consecutive IAIs (induction phase) achieved greater vision improvement (13.8 ± 9.5 letters) than did the residual eyes (- 4.3 ± 9.2 letters) at 1 year (P < .001). Treatment intervals were extended to 12 and 16 weeks in 16.1% (5/31) and 45.2% (14/31) of the patients, respectively. The mean IAI number was 7.0 ± 1.1.

CONCLUSIONS

The results of this study suggest that although the BCVA improvement might be somewhat less than that of frequent treatment, a T&E aflibercept regimen with the longest treatment interval set to 16 weeks is a realizable rational strategy for DME treatment over 1 year.

ASSOCIATION OF SERUM VASOGENIC AND PROINFLAMMATORY FACTORS WITH CLINICAL RESPONSE TO ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR FOR DIABETIC MACULAR EDEMA

PURPOSE

To study the role of serum biomarkers as prognostic factors for qualitative and quantitative response to anti-vascular endothelial growth factor injections for diabetic macular edema (DME).

METHODS

Sixty-seven eyes with DME were treated with intravitreal bevacizumab during a 12-month follow-up period. All cases underwent a baseline workup consisting of 12 inflammatory, metabolic and prothrombotic factors. The following outcomes were evaluated at 3-month intervals until 1 year of follow-up: visual acuity, central subfield thickness (CST), macular volume (MV), % of change from baseline in CST, occurrence of a CST change < 10%, a CST change >20%, and a CST <330 µm, achieving an improvement ≥2 lines of visual acuity, achieving visual acuity ≥20/40.

RESULTS

A significant improvement in CST and visual acuity was seen from third month onwards. Twenty-eight (48.1%) cases were classified as "early responders," 24 (35.8%) as "late responders", and 15 (22.4%) as "poor responders." Serum vascular endothelial growth factor-A levels were significantly lower in "poor responders" (P = 0.006). C-reactive protein (hsCRP) was associated with a limited anatomic response (<10% CST change) (P = 0.002, OR = 1.845, cutoff value of hsCRP = 1.84 mg/L). hsCRP was also negatively associated with obtaining a final CST <330 µm (P = 0.04, r2 = 0.112, OR = 0.643). Baseline visual acuity was significantly associated with 12th month visual acuity (P < 0.001, r2 = 0.602) and also with an improvement ≥2 visual acuity lines (P = 0.009, OR = 20.54).

CONCLUSION

Increased high-sensitivity C-reactive protein was associated with limited anatomic response to anti-vascular endothelial growth factor treatment and persistent DME. Poor responders had significantly lower values of serum vascular endothelial growth factor-A, suggesting an alternative pathogenic pathway for persisting DME.

Evaluation of the Effects of Intravitreal Aflibercept and Ranibizumab on Systemic Inflammatory and Cardiovascular Biomarkers in Patients with Neovascular Age-related Macular Degeneration

Purpose: To investigate the effects of intravitreal ranibizumab (IVR) and intravitreal aflibercept (IVA) on systemic inflammatory and cardiovascular biomarkers in treatment-naive patients with neovascular age-related macular degeneration (nAMD)Methods: This study included 24 eyes of 24 patients treated with 0.5 mg ranibizumab (IVR group) and 25 eyes of 25 patients treated with 2.0 mg aflibercept (IVA group). Complete blood count, C-reactive protein (CRP), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), uric acid (UA), albumin, fibrinogen levels were measured in blood samples before and after the three-monthly loading dose treatment. Neutrophil/lymphocyte ratio (NLR), monocyte/HDL-c ratio (MHR), CRP/albumin ratio (CAR), monocyte/lymphocyte ratio (MLR), platelet/lymphocyte ratio (PLR) were also calculated.Results: A statistically significant decline was determined in post-treatment CRP (P = .002), LDL-c (P < .001) levels, white blood cell (WBC, P = .001), neutrophil (P < .001), monocyte (P = .019) counts and NLR (P = .020), MHR (P = .042), CAR (P = .010) ratios comparing with pre-treatment values in the IVA group. No statistically significant change was found in any of the parameters evaluated in the study in the IVR group. Also, there was no significant change in fibrinogen, lymphocyte count, MLR, HDL-c, UA, PLR, and platelet count values in both groups.Conclusion: Compared to IVR, IVA treatment had a small but significant effect on systemic inflammatory and cardiovascular biomarkers.

TGF-β Serum Levels in Diabetic Retinopathy Patients and the Role of Anti-VEGF Therapy

Transforming growth factor β1 (TGFβ1) is a proinflammatory cytokine that has been implicated in the pathogenesis of diabetic retinopathy (DR), particularly in the late phase of disease. The aim of the present study was to validate serum TGFβ1 as a diagnostic and prognostic biomarker of DR stages. Thirty-eight subjects were enrolled and, after diagnosis and evaluation of inclusion and exclusion criteria, were assigned to six groups: (1) healthy age-matched control, (2) diabetic without DR, (3) non-proliferative diabetic retinopathy (NPDR) naïve to treatment, (4) NPDR treated with intravitreal (IVT) aflibercept, (5) proliferative diabetic retinopathy (PDR) naïve to treatment and (6) PDR treated with IVT aflibercept. Serum levels of vascular endothelial growth factor A (VEGF-A), placental growth factor (PlGF) and TGFβ1 were measured by means of enzyme-linked immunosorbent assay (ELISA). Foveal macular thickness (FMT) in enrolled subjects was evaluated by means of structural-optical coherence tomography (S-OCT). VEGF-A serum levels decreased in NPDR and PDR patients treated with aflibercept, compared to naïve DR patients. PlGF serum levels were modulated only in aflibercept-treated NPDR patients. Particularly, TGFβ1 serum levels were predictive of disease progression from NPDR to PDR. A Multivariate ANOVA analysis (M-ANOVA) was also carried out to assess the effects of fixed factors on glycated hemoglobin (HbA1c) levels, TGFβ1, and diabetes duration. In conclusion, our data have strengthened the hypothesis that TGFβ1 would be a biomarker and pharmacological target of diabetic retinopathy.

Worsening proteinuria and renal function after intravitreal vascular endothelial growth factor blockade for diabetic proliferative retinopathy

Systemic vascular endothelial growth factor (VEGF) inhibitions can induce worsening hypertension, proteinuria and glomerular diseases of various types. These agents can also be used to treat ophthalmic diseases like proliferative diabetic retinopathy, diabetic macular edema, central retinal vein occlusion and age-related macular degeneration. Recently, pharmacokinetic studies confirmed that these agents are absorbed at levels that result in biologically significant suppression of intravascular VEGF levels. There have now been 23 other cases published that describe renal sequela of intravitreal VEGF blockade, and they unsurprisingly mirror known systemic toxicities of VEGF inhibitors. We present three cases where stable levels of proteinuria and chronic kidney disease worsened after initiation of these agents. Two of our three patients were biopsied. The first patient's biopsy showed diabetic nephropathy and focal and segmental glomerulosclerosis (FSGS) with collapsing features and acute interstitial nephritis (AIN). The second patient's biopsy showed AIN in a background of diabetic glomerulosclerosis. This is the second patient seen by our group, whose biopsy revealed segmental glomerulosclerosis with collapsing features in the setting of intravitreal VEGF blockade. Though FSGS with collapsing features and AIN are not the typical lesions seen with systemic VEGF blockade, they have been reported as rare case reports previously. In addition to reviewing known elements of intravitreal VEGF toxicity, the cases presented encompass renal pathology data supporting that intravitreal VEGF blockade can result in deleterious systemic and renal pathological disorders.

Changes in the Systemic Expression of Sirtuin-1 and Oxidative Stress after Intravitreal Anti-Vascular Endothelial Growth Factor in Patients with Retinal Vein Occlusion

OBJECTIVES

Retinal vein occlusions (RVO) are associated with systemic risk factors. However, the ocular occlusive events might also influence a patient's systemic condition. This study tried to investigate serum biomarkers associated with oxidative stress, before and after intravitreal anti-vascular endothelial growth factor (aVEGF) therapy in patients with RVOs.

METHODS

Newly-onset RVO patients were categorized into two groups: comorbid with macular edema requiring aVEGF therapy (treatment group) and no edema (observation group). Age and sex-matched patients (who received cataract surgery) were included as the control group. Intravitreal ranibizumab with a pro-re-nata regimen were administered. Serum samples were collected prior to treatment, at 6 and 12 months after therapy/observation and were collected once before controls who received cataract surgery. mRNA expression of sirtuin-1, its downstream genes, anti-oxidative biomarkers, and proinflammatory cytokines were measured.

RESULTS

There were 32, 26, and 34 patients enrolled in the treatment, observation, and control groups, respectively. The expressions of sirtuin-1 and its downstream genes were significantly lower in patients with RVO compared with the control group. Sirtuin-1 gene expression increased after 1 year of aVEGF therapy in the treatment group but remained unchanged in the observation group. Biomarkers of oxidative stress and proinflammatory cytokines were reduced after 1 year of aVEGF therapy. These biomarkers remained with no changes in the observation group.

CONCLUSIONS

Our study showed that the systemic oxidative stress increased in RVO patients. The aVEGF therapy could alter the gene expression of anti-oxidative proteins and reduce systemic oxidative stress in these patients.

Effect of a Single Intravitreal Bevacizumab Injection on Proteinuria in Patients With Diabetes

Purpose

Proteinuria is the second most common complication after hypertension after systemic administration of bevacizumab. Therefore we aimed to analyze the effect of intravitreal bevacizumab (IVB) injection on proteinuria in patients with diabetes.

Methods

Patients scheduled to receive IVB injection from May 1, 2018, to December 31, 2018, were prospectively enrolled. In total, 53 patients with diabetes (26 with nonproliferative diabetic retinopathy and 27 with proliferative diabetic retinopathy) and 37 patients without diabetes were included. Urine tests were performed within 1 month of and 7 ± 1 days after IVB injection. Urinary protein, creatinine, and albumin concentrations were quantitatively measured, and urinary protein-to-creatinine ratio and urinary albumin-to-creatinine ratio (UACR) were calculated from these data before and after IVB injection.

Results

The mean urinary microalbumin concentrations and urinary protein-to-creatinine ratio were significantly higher in patients with diabetes, both before and after IVB injection. There were no differences between patients with nonproliferative diabetic retinopathy and proliferative diabetic retinopathy. About 80% of patients with diabetes showed improved albuminuria or at least no harmful effect in terms of albuminuria. Patients with deteriorated baseline UACR showed more residual increase in UACR after IVB injection (P < 0.05 in all groups).

Conclusions

Close monitoring of renal function after IVB might be needed in patients with diabetes according to the severity of nephropathy.

Translational Relevance

Our results may provide information regarding the renal function of IVB-treated patients with diabetes.

VEGF: A KEY PLAYER NOT ONLY IN MACULAR DEGENERATION. A REVIEW

The issue of macular retinal degeneration is one of the key areas of ophthalmology. Recent advances in the targeted delivery of vascular endothelial growth factor (VEGF) suppressants have significantly impacted the patient's prognosis in the form of a significant deceleration in disease progression. Some of the drugs have gradually found their use in other indications (central retinal vein occlusion or diabetic macular edema). The following text gives a brief look at the physiology of VEGF, but not only in the eye, but throughout the human body, particularly in the context of adverse effects resulting from systemic inhibition of its effects.

Nephrotoxicity induced by intravitreal vascular endothelial growth factor inhibitors: emerging evidence

Vascular endothelial growth factor (VEGF) inhibitors have emerged as powerful tools to treat malignant neoplasms and ocular diseases by virtue of their ability to inhibit angiogenesis. Recent data indicate that intravitreal injections of VEGF inhibitors can lead to significant systemic absorption as well as a measurable reduction of plasma VEGF activity. There is increasing evidence showing that vitreal absorption of these drugs is associated with cases of accelerated hypertension, worsening proteinuria, glomerular disease, thrombotic microangiopathy, and possible chronic renal function decline. In this review, the 3 most commonly used anti-VEGF agents-bevacizumab, ranibizumab, and aflibercept-are discussed, highlighting their intravitreal absorption and associated effects on the kidney as a target organ system. We provide clinical suggestions for clinicians to both better manage patients receiving anti-VEGF agents intravitreally and detect any putative systemic renal effects of these agents. While acknowledging the risks of aberrant retinal angiogenesis, it is important for clinicians to be aware of the potential for adverse renal risks with use of these agents.