Aflibercept administration in neovascular age-related macular degeneration refractory to previous anti-vascular endothelial growth factor drugs: a critical review and new possible approaches to move forward

Review of Guideline Recommendations for Optimal Anti-VEGF Therapy in Age-Related Macular Degeneration

Neovascular age-related macular degeneration is a progressive, blinding macular disease that has become a burden both in healthcare systems and the global economy. The vascular endothelial growth factor (VEGF) is the main agent involved in the pathogenic process of the disease. The main goal of the age-related macular degeneration treatment is to maintain and improve visual acuity by injecting intravitreal anti-VEGF agents in either a reactive or proactive manner. Subretinal and intraretinal fluids are the main biomarkers that should be considered when managing the frequency of the therapy. This review discusses both functional and morphological treatment criteria according to current recommendations as opposed to real-life situations encountered during day-to-day clinical practice and highlights situations in which the benefits of continuing therapy are arguable in terms of improving patients' quality of life. Optimizing the treatment regimen represents an important aim of current clinical ophthalmological practice, as age-related macular degeneration patients usually have a long follow-up period.

Intraocular neutralizing antibodies against aflibercept in patients with age related macular degeneration

PURPOSE

To detect immunoglobulins in aqueous humour of AMD patients after repeated administration of intravitreal aflibercept.

PATIENTS AND METHODS

Twenty-one patients (age: 77.85 ± 9.21 years) previously treated with intravitreal aflibercept due to wet type age-related macular degeneration (AMD group) and 18 age-matched control subjects (age: 69.75 ± 12.67 years) were included in this study. Patients in the AMD group received a mean of 5 intravitreal injections (min: 1 max: 17) prior to the cataract surgery. Samples of aqueous humour (50 μl) were obtained by anterior chamber paracentesis as the first step of routine cataract surgery. The IgG content of the samples was analysed by an in-house developed ELISA system.

RESULTS

A significant increase in nonspecific IgG levels in the AMD group was detected compared to the control group (13.37 ± 6.65 vs. 9.44 ± 6.55 μg/ml; p = 0.03). In 11 patients, intraocular anti-aflibercept immunoglobulins could be detected (0.05 ± 0.01 μg/ml) which was significantly higher than the limit of detection for anti-aflibercept (0.04 μg/ml; p = 0.001). No correlation was found between the number of injections or the type of CNV and the aqueous level of anti-aflibercept (r = 0.02; p = 0.95).

CONCLUSION

According to our results, penetration of non-specific systemic antibodies through the impaired blood-retinal barrier is higher in patients with neovascular AMD than in subjects with an intact structural barrier. Evaluation of neutralizing antibodies to anti-VEGF agents in the aqueous humour can lead us to understanding tachyphylaxis and changes in intraocular immune mechanisms due to AMD.

Managing Neovascular Age-Related Macular Degeneration in Clinical Practice: Systematic Review, Meta-Analysis, and Meta-Regression

The use of anti-vascular endothelial growth factor (VEGF) agents has profoundly changed the prognosis of neovascular age-related macular degeneration (nAMD). As clinical experiences have accumulated, it has become mandatory to summarize data to give information that can be useful in everyday practice. We conducted a systematic review to identify randomized controlled trials (RCTs) and observational studies that reported 12-month changes in best-corrected visual acuity (BCVA) in patients with nAMD on anti-VEGF monotherapy. Data were analyzed in a random-effects meta-analysis with BCVA change as the primary outcome. Meta-regression was conducted to evaluate the impact of multiple covariates. Four hundred and twelve heterogeneous study populations (109,666 eyes) were included. Anti-VEGFs induced an overall improvement of +5.37 ETDRS letters at 12 months. Meta-regression showed that mean BCVA change was statistically greater for RCTs (p = 0.0032) in comparison with observational studies. Populations following a proactive regimen had better outcomes than those following a reactive treatment regimen. Mean BCVA change was greater in younger populations, with lower baseline BCVA and treated with a higher number of injections (p < 0.001). Our results confirm that anti-VEGFs may produce a significant functional improvement at 12 months in patients with nAMD.

A Cyclic Peptide Epitope of an Under-Explored VEGF-B Loop 1 Demonstrated In Vivo Anti-Angiogenic and Anti-Tumor Activities

Pathological angiogenesis is mainly initiated by the binding of abnormal expressed vascular endothelial growth factors (VEGFs) to their receptors (VEGFRs). Blocking the VEGF/VEGFR interaction is a clinically proven treatment in cancer. Our previous work by epitope scan had identified cyclic peptides, mimicking the loop 1 of VEGF-A, VEGF-B and placental growth factor (PlGF), inhibited effectively the VEGF/VEGFR interaction in ELISA. We described here the docking study of these peptides on VEGFR1 to identify their binding sites. The cellular anti-angiogenic activities were examined by inhibition of VEGF-A induced cell proliferation, migration and tube formation in human umbilical vein endothelial cells (HUVECs). The ability of these peptides to inhibit MAPK/ERK1/2 signaling pathway was examined as well. On chick embryo chorioallantoic membrane (CAM) model, a cyclic peptide named B-cL1 with most potent in vitro activity showed important in vivo anti-angiogenic effect. Finally, B-cL1 inhibited VEGF induced human gastric cancer SGC-7901 cells proliferation. It showed anti-tumoral effect on SGC-7901 xenografted BALB/c nude mouse model. The cyclic peptides B-cL1 constitutes an anti-angiogenic peptide drug lead for the design of new and more potent VEGFR antagonists in the treatment of angiogenesis related diseases.

A Novel Small Peptide H-KI20 Inhibits Retinal Neovascularization Through the JNK/ATF2 Signaling Pathway

Purpose

Abundant evidence has shown benefits of antivascular endothelial growth factor (anti-VEGF) therapies in neovascular eye diseases. However, the high cost, side effects, and inconvenience of frequent injections demand alternative novel drug candidates. This study aimed to analyze antiangiogenic effects of peptide H-KI20 and illustrated signaling mechanisms.

Methods

Live cell culture and tracing, wound healing assay, and tube formation were performed in human retinal microvascular endothelial cells (HRECs). The chick embryo chorioallantoic membrane and mouse oxygen-induced ischemic retinopathy model were applied to examine the effects of H-KI20 in vivo. The intracellular signaling pathways were examined. Molecular docking and surface plasmon resonance assay were used to validate the direct interaction of H-KI20 and c-Jun N-terminal kinase 2 (JNK2).

Results

H-KI20 had high penetration ability in vitro and in vivo. It inhibited motility, migration, and tube formation of HRECs, without cytotoxicity, and inhibited angiogenesis in vivo. Furthermore, H-KI20 treatment reduced the phosphorylation level of activating transcription factor 2 (ATF2) stimulated by VEGF via downregulating p-JNK. H-KI20 bound to JNK2 directly with a dissociation constant value of 83.68 µM. The knockdown of ATF2 attenuated VEGF-induced tube formation and decreased the movement speed of HRECs.

Conclusions

H-KI20 inhibited angiogenesis both in vitro and in vivo. The ratios of p-ATF2/ATF2 and p-JNK/JNK stimulated by VEGF were decreased by H-KI20, and H-KI20 targeted JNK2 directly. In addition, the pivotal role of ATF2 in VEGF-induced retinal neovascularization was elucidated for the first time. Taken together, H-KI20 displays potential for pathological retinal angiogenesis as a sustained and low-toxic peptide.

Tachyphylaxis during treatment of exudative age-related macular degeneration with aflibercept

PURPOSE

At present, the standard treatment of neovascular age-related macular degeneration (AMD) is the repeated administration of antivascular endothelial growth factor (VEGF) agents. However, we often encounter patients who develop tachyphylaxis for anti-VEGF agents. In this study, we investigated the characteristics of patients who developed tachyphylaxis on repeated intravitreal aflibercept (IVA) injections for neovascular AMD and the frequency of tachyphylaxis.

METHODS

Three hundred thirteen eyes (313 patients) with treatment-naïve AMD who achieved resolution soon after starting IVA and were followed up for ≥ 12 months were enrolled in this retrospective, interventional, consecutive case series. The eyes were investigated for tachyphylaxis to aflibercept. Tachyphylaxis was defined as absence of any improvement (more than 100 μm) in or worsening of CRT within 1 month after more than two repeated monthly IVA injections when the exudative change remained.

RESULTS

Twenty-eight (8.9%) of the 313 eyes developed tachyphylaxis (occult with no classic, n = 14; polypoidal choroidal vasculopathy, n = 14) at an annual rate of about 3%. The mean number of IVA injections was 10.5 ± 7.8, and the mean interval until tachyphylaxis was 20.9 ± 14.0 months. There was a significant difference in the AMD subtypes between the group with tachyphylaxis and the group without it (p = 0.0029). Occult with no classic type and polypoidal choroidal vasculopathy were the only AMD subtypes in the eyes with tachyphylaxis. In the analysis of the eyes that had occult with no classic or polypoidal choroidal vasculopathy, only intraretinal edema was significantly less common (p = 0.042). A combination of photodynamic therapy and aflibercept was effective in 13 (87%) of 15 eyes with tachyphylaxis, and switching to intravitreal ranibizumab was effective in 5 (56%) of 9 eyes.

CONCLUSIONS

Tachyphylaxis occurs after repeated IVA injections in a minority of patients with AMD for a long term and is more likely to occur in eyes with lesions beneath the retinal pigment epithelium and no intraretinal edema. Treatment of AMD should be performed keeping this fact in mind, while considering the consecutive treatment.

Activated protein C induces suppression and regression of choroidal neovascularization- A murine model

Activated protein C (APC) exerts diverse cell signaling pathways which results in multiple distinct cytoprotective actions. These include anti-apoptotic and anti-inflammatory activities and stabilization of endothelial and epithelial barriers. We studied the ability of APC to inhibit the leakage and the growth of newly formed as well as pre-existing choroidal neovascularization (CNV) and examined the ability of APC to stabilize the Retinal Pigmented Epithelium (RPE). We explored the contribution of Tie2 receptor to the protective effects of APC. CNV was induced by laser photocoagulation in C57BL/6J mice. APC was injected intravitreally immediately or 7 days after CNV induction. Neovascularization was evaluated on RPE-choroidal flatmounts using FITC-dextran perfusion and CD31 immunofluorescence. CNV leakage was measured by fluorescein angiography (FA). The ability of APC to stabilize the RPE barrier was evaluated in-vitro by dextran permeability and zonula occludens 1 (ZO1) immunostaining. Tie2 blocking was induced in-vivo by intraperitoneal injection of Tie2 kinase inhibitor and in-vitro by incubation with anti Tie2 antibodies. APC treatment dramatically inhibited the generation of newly formed CNV leakage sites and reversed leakage in 85% of the pre-existing CNV leaking sites. In RPE cell culture, APC induced translocation of ZO1 to the cell membrane, accompanied by reduction in permeability of the monolayer. Inhibition of Tie2 significantly decreased APC protective activities in both the mouse model and the RPE cell culture. Our results show that APC treatment significantly inhibits the leakage and growth of newly formed, as well as pre-existing CNV, and its protective activities are partially mediated via the Tie2 receptor. The data suggest that APC should be further investigated as a possible effective treatment for CNV.

Intravitreal aflibercept efficacy in neovascular age-related macular degeneration with suboptimal response to anti-vascular endothelial growth factor-A therapy

IMPORTANCE

To provide new insights into aflibercept effect in non-naive-treated patients with neovascular age-related macular degeneration.

PURPOSE

To assess the efficacy of intravitreal aflibercept in patients with neovascular age-related macular degeneration without optimal response to previous anti-vascular endothelial growth factor A therapy.

DESIGN

Single-arm, multi-centre, prospective study.

PARTICIPANTS

Patients ⩾50 years with active neovascular age-related macular degeneration, best-corrected visual acuity between 20/32 and 20/320 with suboptimal response to ranibizumab or bevacizumab.

METHODS

Aflibercept was administered monthly (3-first months), and bimonthly thereafter until month 8. Anatomical and functional outcomes were assessed.

MAIN OUTCOME MEASURE

Percentage of eyes without intra or subretinal fluid on optical coherence tomography after 3-monthly loading doses of aflibercept.

RESULTS

A total of 46 patients were included. At week 12, 45.7% (95% confidence interval: 31.5%-60.1%) of eyes showed no fluid on optical coherence tomography. The mean (standard deviation) best-corrected visual acuity increased from 65.1 (8.3) to 69.6 (8.1) letters (+4.5 (5.8) p < 0.0001) and was stabilized at week 40 as compared to baseline. Mean central macular thickness decreased from 430 (119) µm to 323 (100) µm at week 12 (-107 (90) µm, p < 0.0001) and was reduced at week 40 (-46 (111) µm, p = 0.0056). At week 40, 21.7% (95% confidence interval: 9.8%-33.7%) had no fluid. There was a case of presumed noninfectious endophthalmitis that was successfully managed.

CONCLUSION

Almost half of patients presented no fluid on optical coherence tomography at week 12, and there was a clinically significant improvement in best-corrected visual acuity. At week 40, one in five patients did not show intra or subretinal fluid, central macular thickness decreased and best-corrected visual acuity was stabilized compared to baseline.

A meta-analysis of patients with treatment-resistant macular oedema secondary to retinal vein occlusions following switching to aflibercept

To systematically review anatomical and functional outcomes of switching therapy from bevacizumab and/or ranibizumab to aflibercept in patients with persistent macular oedema secondary to retinal vein occlusions (RVO). A systematic search of aflibercept for the treatment of persistent macular oedema secondary to branch and central RVO was performed in EMBASE, PubMed and Cochrane databases prior to June 2017. The main outcome variables described were best-corrected visual acuity (BCVA) and central macular thickness (CMT). All results were analysed and pooled using random-effects models with 95% confidence intervals (CI). Eight studies met the inclusion criteria with a total of 137 eyes, incorporating both branch and central RVO. Meta-analysis demonstrated a nonsignificant change in BCVA at 6 and 12 months following switch to aflibercept (4.40 letters, 95% CI: -3.10 to 11.90, p = 0.25 and 3.10 letters, 95% CI: -1.74 to 7.94, p = 0.21, respectively). Significant improvement in mean CMT was observed after switch to aflibercept at 6 (-256.00 μm, 95% CI: -318.00 to -194.00, p < 0.001) but not 12 months (-118.00 μm, 95% CI: -261.00 to 25.00, p = 0.11). Switching from bevacizumab/ranibizumab to aflibercept may improve persistent macular oedema secondary to RVO. However, there may be a limitation in the potential of visual recovery.

Bevacizumab dosing every 2 weeks for neovascular age-related macular degeneration refractory to monthly dosing

PURPOSE

To evaluate intravitreal bevacizumab every 2 weeks (biweekly) in refractory neovascular age-related macular degeneration (nAMD).

STUDY DESIGN

Retrospective study.

METHODS

A retrospective study of consecutive nAMD patients unresponsive to monthly intravitreal anti-vascular endothelial growth factor (VEGF) switched to 3-4 biweekly injections.

RESULTS

Twenty-seven eyes of patients aged 82.08  ± 6.85 years were included. Prior to the 2-week interval bevacizumab injections, 74.1% (n=20) were treated with both bevacizumab and ranibizumab, 11.1% (3 eyes) also received aflibercept and 14.8% (4 eyes) had received prior treatment of monthly bevacizumab (average number of injections 21.5 ± 6.7). Best corrected visual acuity (BCVA) remained stable between baseline (logMAR 0.72± 0.60) and follow-up (0.76± 0.66) (p=0.41). Mean central macular thickness and macular volume did not change significantly between baseline and follow-up (p=0.35 and p=0.60, respectively). Six eyes (22.2%) showed morphologic anatomic improvements, while 19 eyes (70.4%) were stable and two eyes (7.4%) deteriorated from baseline. Subretinal fluid completely resolved in 3 of the eyes and improved in the other 3 eyes and in this group (22.2%) both central macular thickness (326.2 ± 101.4 versus 297.5 ± 97.2, p=0.002) and macular volume (8.69 ± 1.69 versus 8.22 ± 1.43, p=0.03) were significantly reduced. No adverse events were observed in any of the treated eyes.

CONCLUSION

This study demonstrates that biweekly bevacizumab injections are effective in nearly one-quarter of nAMD non-responders with no adverse events reported. Switching earlier, rather than later, to this low cost modality may be of benefit for a portion of non-responders to conventional treatment.

VISUAL ACUITY IMPROVEMENT WHEN SWITCHING FROM RANIBIZUMAB TO AFLIBERCEPT IS NOT SUSTAINED

PURPOSE

To assess whether visual benefits exist in switching to aflibercept in patients who have been chronically treated with ranibizumab for neovascular age-related macular degeneration.

METHODS

A multicenter, national, electronic medical record database study was performed. Patients undergoing six continuous monthly ranibizumab injections and then switched to continuous aflibercept were matched to those on continuous ranibizumab therapy. Matching was performed in a 2:1 ratio and based on visual acuity 6 months before and at the time of the switch, and the number of previous ranibizumab injections.

RESULTS

Patients who were switched to aflibercept demonstrated transiently significant improvement in visual acuity that peaked at an increase of 0.9 Early Treatment Diabetic Retinopathy Study letters 3 months after the switch, whereas control patients continued on ranibizumab treatment showed a steady decline in visual acuity. Visual acuity differences between the groups were significant (P < 0.05) at 2, 3, and 5 months after the switch. Beginning at 4 months after the switch, the switch group showed a visual acuity decline similar to the control group.

CONCLUSION

Transient, nonsustained improvement in visual acuity occurs when switching between anti-vascular endothelial growth factor agents, which may have implications in treating patients on chronic maintenance therapy on one anti-vascular endothelial growth factor medication.

Effects of Aflibercept for Neovascular Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis of Observational Comparative Studies

Purposes

To compare the effects of aflibercept and other anti-vascular endothelial growth factor (anti-VEGF) medications on both functional and anatomical outcomes for treatment-naïve neovascular age-related macular degeneration (nAMD) in the real world.

Methods

A systematic review and meta-analysis of observational comparative studies.

Results

A total of 18 studies remained after literature selection and quality assessment of 1697 studies. The most common aflibercept treatment regimen was three monthly injections followed by pro re nata (PRN). Aflibercept and ranibizumab had similar effects in 2-year treatment. At 3, 6, 12, and 24 months, the differences in the logarithm of minimum angle of resolution (logMAR) decrease in aflibercept and ranibizumab groups were 0.00 (95% confidence interval [CI]: −0.03 to 0.02); 0.01 (95% CI: −0.02 to 0.05); −0.03 (95% CI: −0.07 to 0.01); and –0.06 (95% CI: −0.30 to 0.17), respectively; the differences in decrease of central retinal thickness (CRT) were 3.25 μm (95% CI: −15.03 to 21.53); 7.89 μm (95% CI: −31.91 to 47.69); 2.89 μm (95% CI: −18.33 to 24.11); and −2.42 μm (95% CI: −77.87 to 73.03), respectively. However, aflibercept was significantly more effective in patients with initial reduced visual acuity (logMAR >0.6 or <55 letters; P = 0.001). In the first year, treatment frequency was not significantly different for aflibercept and ranibizumab, but aflibercept required fewer injections than ranibizumab with PRN regimen (mean −0.90; 95% CI: −1.80 to 0.00).

Conclusions

Aflibercept has comparable effects with ranibizumab for treatment-naïve nAMD in the real world, and may be more effective for patients with initial lower visual acuity.

Clinical Applications of Dexamethasone for Aged Eyes

The risk of severe eye problems has been found to increase significantly with age, particularly between the fifth and sixth decades of life. Cataracts, dry eye, neovascular age-related macular degeneration, diabetic retinopathy and retinal vein occlusion (RVO) are very common and very different age-related ocular diseases that reduce the patient's quality of life. The rationale for using corticosteroids to treat anterior and posterior ocular segment diseases is driven by inflammation. Dexamethasone, one of the most powerful corticosteroids available, is widely used for topical or intravitreal administration. Topical dexamethasone has proven efficacy for the management of postoperative inflammation in the anterior segment after cataract surgery and symptom relief in dry-eye disease. A new sustained-release 700 µg dexamethasone intravitreal implant (DEX) was recently approved for the treatment of macular edema following RVO, diabetic macular edema, or non-infectious uveitis, and its use is increasing, especially when other therapeutic agents have failed. The most common side effects are increased intraocular pressure and cataract formation. The potency of DEX, alone or in combination with other agents, makes DEX a promising option for treating several retinal diseases.

Interleukin-13 and age-related macular degeneration

AIM

o identify the effects of interleukin (IL)-13 on retinal pigment epithelial (RPE) cells and the IL-13 level in aqueous humor of age-related macular degeneration (AMD) patients.

METHODS

IL-13 levels in aqueous humor specimens from AMD patients were detected with enzyme-linked immunosorbent assay (ELISA). ARPE-19 cells were treated with 10 ng/mL IL-13 for 12, 24, and 48h. The cell proliferaton was evaluated by the MTS method. The mRNA and protein levels of α-SMA and ZO-1 were evaluated with quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot respectively. The expression of tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β) and vascular endothelial growth factor (VEGF) were assessed by ELISA.

RESULTS

IL-13 levels in the aqueous humor of patients with AMD were significantly higher than those in the control (167.33±17.64 vs 27.12±5.65 pg/mL; P<0.01). In vitro, IL-13 of high concentrations (10, 15, and 20 ng/mL) inhibited ARPE-19 cell proliferation. α-SMA mRNA in ARPE-19 cell were increased (1.017±0.112 vs 1.476±0.168; P<0.001) and ZO-1 decreased (1.051±0.136 vs 0.702±0.069; P<0.001) after treated with 10 ng/mL IL-13 for 48h. The protein expression of α-SMA and ZO-1 also showed the same tendency (α-SMA: P=0.038; ZO-1: P=0.008). IL-13 significantly reduced the level of TNF-α (44.70±1.67 vs 31.79±3.53 pg/mL; P=0.005) at 48h, but the level of TGF-β2 was significantly increased from 34.44±2.92 to 57.61±6.31 pg/mL at 24h (P=0.004) and from 61.26±1.11 to 86.91±3.59 pg/mL at 48h (P<0.001). While expressions of VEGF didn't change after IL-13 treatment.

CONCLUSION

IL-13 in vitro inhibit ARPE-19 cell proliferation and expression in the aqueous may be associated with AMD.

Aflibercept as a Second Line Therapy for Neovascular Age Related Macular Degeneration in Israel (ASLI) study

PurposeThe purpose of this study is to evaluate an early switch to aflibecept in eyes with neovascular age-related macular degeneration (nvAMD) showing partial or lack of response for initial therapy with bevacizumab.MethodsThe Aflibercept as a Second Line Therapy for Neovascular Age Related Macular Degeneration in Israel (ASLI) was a prospective, multicenter, single-arm clinical trial. Eyes with nvAMD having incomplete response to 3-9 prior bevacizumab injections were recruited. Three monthly intravitreal aflibercept (2 mg) injections were administered, followed by two bi-monthly injections and a final examination at week 28. An optional injection was allowed at week 20.ResultsForty-seven eyes of 46 patients (mean±SD age 76±8 years) were recruited. The mean number of prior bevacizumab injections was 5.5±2.9. The mean visual acuity improved from 60.3±10 ETDRS letters at baseline to 63.1±15 letters at week 28 (P=0.02, paired t-test). The central subfield thickness (CST) reduced from 409±127 micron at baseline to 330±110 microns at week 4 (P=0.0002; paired t-test), and 277±70 microns at week 28 (P=0.00002; paired t-test). Twenty-two eyes had three to five prior bevacizumab injections (mean 5.1±0.7), and 25 eyes had six to nine prior injections (7.32±1.2). Both groups had reduced CST from baseline to week 28 (P=0.0004 and P=0.0007; paired t-test, respectively). Thirty-five (75%) eyes required the optional additional aflibercept injection at week 20.ConclusionsThe ASLI study demonstrated improved BCVA and reduced CST following an early switch to aflibercept therapy in eyes with prior incomplete response to initial therapy with three to nine bevacizumab injections.

Switching to aflibercept among patients with treatment-resistant neovascular age-related macular degeneration: a systematic review with meta-analysis

Purpose

To systematically review anatomical and functional outcomes subsequent to switching from bevacizumab/ranibizumab to aflibercept monotherapy in patients with treatment-resistant neovascular age-related macular degeneration (nAMD).

Design

Systematic review and meta-analysis.

Methods

Medline, PubMed, Embase, and Cochrane databases were searched up to July 2016 for available scientific literature which met inclusion criteria. Eligible studies reported visual and anatomical outcomes with at least 6 months of follow-up among patients with nAMD and persistent or resistant exudative fluid despite previous anti-vascular endothelial growth factor (VEGF) therapy (bevacizumab and/or ranibizumab) and were switched to aflibercept monotherapy. Mean changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were pooled using random-effects models with 95% confidence intervals (CIs).

Results

Of 82 papers reviewed, 28 studies met inclusion criteria of this review. Pooled results showed a small mean improvement in BCVA at 6 and 12 months following switching (1.11 letters, 95% CI −0.25 to 2.46, P=0.17 and 0.63 letters, 95% CI −0.26 to 1.52, P=0.17, respectively). There was a significant improvement in mean CRT following switching (−61.90 µm, 95% CI −77.10 to −46.80, P<0.001 and −50.00 µm, 95% CI −63.20 to −36.80, P<0.001 at 6 and 12 months, respectively).

Conclusion

Pooled analysis demonstrated significantly improved anatomical outcomes; however, visual function remained stable, having a comparable effect to other anti-VEGF agents in preservation of vision. These patients had poorly responsive chronic disease with limited potential for visual recovery. Switching to aflibercept with frequent monitoring may be a suitable option for patients who have developed treatment resistance.

Vascular endothelial growth factor: a neurovascular target in neurological diseases

Brain function critically relies on blood vessels to supply oxygen and nutrients, to establish a barrier for neurotoxic substances, and to clear waste products. The archetypal vascular endothelial growth factor, VEGF, arose in evolution as a signal affecting neural cells, but was later co-opted by blood vessels to regulate vascular function. Consequently, VEGF represents an attractive target to modulate brain function at the neurovascular interface. On the one hand, VEGF is neuroprotective, through direct effects on neural cells and their progenitors and indirect effects on brain perfusion. In accordance, preclinical studies show beneficial effects of VEGF administration in neurodegenerative diseases, peripheral neuropathies and epilepsy. On the other hand, pathologically elevated VEGF levels enhance vessel permeability and leakage, and disrupt blood-brain barrier integrity, as in demyelinating diseases, for which blockade of VEGF may be beneficial. Here, we summarize current knowledge on the role and therapeutic potential of VEGF in neurological diseases.

Visual and anatomic outcomes after conversion to aflibercept in neovascular age-related macular degeneration: 12-month results

PURPOSE

To investigate 12-month outcomes of conversion to aflibercept in patients with neovascular age-related macular degeneration resistant to ranibizumab.

METHODS

Twenty-two eyes of 19 consecutive patients received 3 monthly aflibercept injections followed by a pro re nata protocol. Spectral-domain optical coherence tomography (OCT) images were obtained before each injection. All 49 cross-sectional OCT B-scans obtained in each examination were investigated and the largest choroidal neovascularization (CNV) size was chosen. The same cross-sectional B-scan sections containing the maximum CNV size were used during the follow-up.

RESULTS

After 12 months, best-corrected visual acuity increased from 45.68 ± 20.25 to 59.09 ± 17.50 Early Treatment Diabetic Retinopathy Study letters (p&lt;0.001), central subfield thickness decreased from 399.91 ± 148.85 to 304.55 ± 97.89 μm (p = 0.003), area of CNV declined from 0.38 ± 0.24 to 0.28 ± 0.19 mm2 (p = 0.003), and macular volume improved from 9.64 ± 1.75 to 8.45 ± 0.98 mm3 (p&lt;0.001). There was a significant resolution of intraretinal fluid (p = 0.016), but reduction of subretinal fluid was not significant (p = 0.25).

CONCLUSIONS

Visual and anatomic improvement were obtained after conversion to aflibercept.

Conversion back to bevacizumab or ranibizumab for recurrent neovascular activity with aflibercept in age-related macular degeneration: a case series

Background

Neovascular age-related macular degeneration often requires chronic therapy with anti-VEGF agents, and patients with recurrent disease are challenging to manage.

Methods

This retrospective case series evaluates patients who were switched from bevacizumab or ranibizumab to aflibercept and then back again because of recurrent fluid on optical coherence tomography (OCT) by reporting changes in OCT measurements over the course of medication changes.

Results

Twenty-one eyes in nineteen patients received an average of 20.7 bevacizumab and/or ranibizumab injections and then an average of 7.2 aflibercept injections before being switched back to bevacizumab or ranibizumab because of recurrent fluid on OCT. Median central macular thickness improved on transition from bevacizumab or ranibizumab (317 μm) to aflibercept (285 μm; p = 0.034), then worsened over the course of aflibercept treatment (296 μm; p = 0.080), but improved again with transition from aflibercept back to bevacizumab or ranibizumab (283 μm; p = 0.016). The total volume of subretinal fluid, intraretinal fluid, and pigment epithelial detachments also decreased on transition from bevacizumab or ranibizumab (2.56 mm³) to aflibercept (2.44 mm³; p = 0.080), then worsened over the course of aflibercept treatment (3.18 mm³; p = 0.019), and improved again on transition back to bevacizumab or ranibizumab (2.11 mm³; p = 0.016).

Conclusions

While aflibercept appears initially effective, some patients develop recurrent fluid with aflibercept that improves with transition back to bevacizumab or ranibizumab. Rotating anti-VEGF agents may be beneficial with recurrent neovascular activity.