Loss of reactivity in intravitreal anti-VEGF therapy: tachyphylaxis or tolerance?

"What should I inject next?" Challenging treatment decisions in the multiple anti-VEGF: a review of publications exploring anti-VEGF switching for nAMD

PURPOSE

The purpose of our work was to collate information from studies published to date focusing on switching in anti-VEGF therapy and describe the currently available data on anti-VEGF switching in nAMD.

METHODS

A PubMed search of published articles from January 2010 to January 2017 was conducted. Published studies were compared in parameters of sample size, reason for switch, duration of follow-up, and switch outcome (functional and anatomical).

RESULTS

Our search revealed 31 relevant publications. Switching from bevacizumab to ranibizumab mostly resulted in improvement in visual acuity (VA) and anatomical outcomes (CMT, CRT; 7/8 and 6/8 studies, respectively), whereas switching from ranibizumab to bevacizumab was less effective (no VA or anatomical improvement in 2/4 studies). Switching from either agent to aflibercept resulted mostly in improvement of anatomical outcomes (19/21 studies), but rarely in VA improvement (6/21 studies). Not all results were statistically significant, likely due to small sample sizes.

CONCLUSION

Switching anti-VEGF therapy from bevacizumab to ranibizumab might be of benefit (functionally and anatomically) for patients who failed to improve with intravitreal bevacizumab injections, whereas switching from either agent to aflibercept resulted mostly in reduced macular thickness only.

Neovascular age-related macular degeneration: intraocular inflammatory cytokines in the poor responder to ranibizumab treatment

Purpose

To determine the levels of interleukin (IL)-6, vascular endothelial growth factor-A, platelet-derived growth factor, placental growth factor (PLGF), and other cytokines in the aqueous fluid of patients with neovascular age-related macular degeneration who respond poorly to ranibizumab.

Patients and methods

This is an observational, prospective study. Thirty-two eyes from 30 patients were included in the study: 11 patients who responded poorly to ranibizumab and were switched to aflibercept (AF group), 8 patients who received ranibizumab and photodynamic therapy (PDT group), and 13 patients who responded to ranibizumab (control group). Aqueous fluid samples were collected for analysis of cytokine levels at baseline and after 1, 2, and 3 months of treatment. The effect of treatment on cytokine levels was compared between the study groups and between different time points using a linear mixed-effect regression model.

Results

In the AF group, there was an increase in vascular endothelial growth factor-C, IL-7, and angiopoeitin-2 levels (P=0.01) and a decrease in intercellular adhesion molecule and IL-17 levels (P=0.01) between baseline and 3 months. After adjustment for age, sex, race, and type of lesion at baseline, the PLGF level was higher (P=0.02) and the IL-7 level was lower (P=0.04) in the ranibizumab non-responder group than in the ranibizumab responder group.

Conclusion

Switching from ranibizumab to aflibercept did not reduce intraocular levels of angiogenesis cytokines, but resulted in improvement of central subfield thickness. PLGF levels were higher in poor responders to ranibizumab. The response of lesions to medication might be related to the stage of choroidal neovascularization.

Trial registration

www.ClinicalTrial.gov (NCT02218177c).

Effectiveness of Continued Ranibizumab Therapy in Neovascular Age-Related Macular Degeneration versus Switch to Aflibercept: Real World Evidence

PURPOSE

To assess the long-term comparative effectiveness of ranibizumab versus switching to aflibercept in neovascular age-related macular degeneration (nAMD).

DESIGN

A 24-month, retrospective, comparative, nonrandomized, matched cohort study.

PARTICIPANTS

Patients with nAMD initiated on ranibizumab who remained (nonswitchers) or who switched to aflibercept (switchers) captured from a United States electronic medical records database between July 1, 2011 and October 12, 2014.

METHODS

Patient eyes were matched for baseline age, baseline visual acuity (VA), VA at month 3, and duration of follow-up. Matching ratio was 1:2 (switchers: nonswitchers) where possible and 1:1 otherwise.

MAIN OUTCOME MEASURES

The primary outcome was VA change from baseline (first injection of ranibizumab) to month 24. Secondary end points were standardized area under the curve of VA change; patient eyes (%) gaining or losing ≥5, ≥10, or ≥15 letters, or with VA of >73 letters at month 24; number of injections and monitoring visits; and analysis of preswitch characteristics.

RESULTS

A total of 454 switchers and 750 matched nonswitchers were included. The adjusted difference in mean VA change from baseline to month 24 for switchers to nonswitchers was 0.02 letters (95% confidence interval [CI], -1.63 to 1.68). The upper bound 95% CI (1.68) was below the predefined noninferiority margin of 5 letters. Switchers had a significantly higher annualized number of mean total visits compared with nonswitchers (10.0 vs. 9.0 for year 1; 8.7 vs. 7.4 for year 2), a higher number of injection visits (8.4 vs. 6.7 for year 1; 7.0 vs. 5.1 for year 2), but a lower number of monitoring-only visits (1.6 vs. 2.3 for year 1; 1.7 vs. 2.3 for year 2). During the preswitch period, switchers had a higher number of injection visits (7.6 vs. 6.5), fewer monitoring-only visits (1.5 vs. 2.2), and comparable total visits (9.1 vs. 8.7). Visual acuity change from baseline to switch was similar between switchers and nonswitchers (adjusted least squares mean difference, -1.36 letters; 95% CI, -2.76 to 0.05).

CONCLUSIONS

Switching patients from ranibizumab to aflibercept resulted in no difference in VA change compared with those maintained on ranibizumab only. The lower retreatment rate in nonswitchers compared with switchers post switch does not support the view of a longer treatment efficacy.

The outcomes of aflibercept therapy in patients with age-related macular degeneration resistant to bevacizumab or ranibizumab

Purpose

This study was designed to assess the functional and anatomic outcomes of intravitreal aflibercept injection in patients with wet age-related macular degeneration (AMD) refractory to intravitreal bevacizumab or ranibizumab therapy.

Methods

This retrospective study included 43 eyes of 43 patients resistant to treatment with at least 6 injections of bevacizumab or ranibizumab. Persistent intraretinal and subretinal fluid (IRF and SRF) on optical coherence tomography (OCT), no improvement in best corrected visual acuity (BCVA), and a central macular thickness (CMT) increase of more than 100 μm due to SRF and/or IRF compared to baseline for at least 6 monthly intravitreal bevacizumab or ranibizumab injections were defined as resistant to bevacizumab/ranibizumab therapy. BCVA, intraocular pressure (IOP), CMT, maximum retinal thickness (MRT), and maximum pigment epithelial detachment (PED) height (MPEDH) were evaluated before and after aflibercept injections.

Result

After initiating aflibercept treatment, the mean final BCVA logarithm of the minimum angle of resolution or recognition (logMAR) improved to 0.84 ± 0.59 which was statistically significant compared to baseline (1.14 ± 0.51), (P < 0.001). After aflibercept injection, statistically significant reduction was noted in mean CMT (402.6 ± 196.7 μm vs 264.2 ± 52.85 μm, P < 0.05), MRT (435.3 ± 195.2 μm vs 282.2 ± 31.8 μm, P < 0.05), and MPEDH (154.2 ± 86.0 μm vs 68.3 ± 70.6 μm, P < 0.05). There was no correlation between the total number of previous injections and the increase of BCVA (r = −0.10, P = 0.265). The decrease of mean IOP was statistically significant under aflibercept treatment (P < 0.001).

Conclusions

The present study showed the efficacy of aflibercept treatment in eyes with persistent retinal or SRF under bevacizumab or ranibizumab therapy. A significant anatomical and functional improvement was noted.

HIGH-DOSE HIGH-FREQUENCY AFLIBERCEPT FOR RECALCITRANT NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

This retrospective study demonstrated 4 mg monthly aflibercept is effective in treating recalcitrant neovascular age-related macular degeneration. Sustainable significant anatomical improvement was shown starting 1 month after initiating the treatment, and 45% of the treated eyes showed vision improvement of 1 line or more at the last visit.

Purpose:

To determine the efficacy of monthly (0.1 mL/4 mg) aflibercept for refractory neovascular age-related macular degeneration (wet age-related macular degeneration).

Methods:

This was a retrospective interventional case series in which patients with wet age-related macular degeneration were treated with stepwise dose escalation. Nonvitrectomized patients resistant to monthly (Q4W) ranibizumab/bevacizumab were switched to 2 mg aflibercept every 8 weeks. With resistance, they were escalated to Q4W 2 mg aflibercept, then Q4W 4 mg (high dose high frequency, 4Q4W) aflibercept. Resistance was defined as ≥2 recurrences after being dry following ≥3 injections or persistent exudation on treatment of ≥5 injections.

Results:

Thirty-three eyes of 28 patients were treated with 4Q4W aflibercept and followed for a mean of 16 months. A dry retina (no intraretinal or subretinal fluid) was achieved after initiating 4Q4W aflibercept treatment at a mean of 3.8 months. Central foveal thickness, maximum foveal thickness, intraretinal fluid, subretinal fluid, and retinal pigment detachment height decreased significantly at 1 month after initiating the 4Q4W aflibercept, and the morphologic therapeutic effect was sustained until the last visit. Forty-five percent of eyes had one or more lines of vision improvement. New geographic atrophy developed in 9% of eyes during follow-up. No ocular or systemic adverse events occurred after initiating 4Q4W aflibercept.

Conclusion:

Intravitreal high-dose high-frequency aflibercept is an effective treatment for patients with refractory wet age-related macular degeneration.

Real-life experience of ranibizumab for diabetic macular edema in Taiwan

PURPOSE

To evaluate the visual and anatomical outcomes of intravitreal ranibizumab for diabetic macular edema (DME) in the healthcare system of Taiwan.

METHODS

A total of 39 eyes from 39 patients were retrospectively enrolled in the study. All eyes that fulfilled the key criteria, including a baseline vision between 20 and 70 ETDRS letters and a minimum central macular thickness (CMT) of 300 µm, had at least 3 monthly loading injections of ranibizumab in a year. Macular laser or posterior subtenon injections of triamcinolone acetonide (PSTA) could be performed as supplementary treatments following loading injections. Primary outcomes include best-corrected visual acuity and CMT.

RESULTS

Patients' vision improved from 46.5 ± 15.3 letters at baseline to 51.4 ± 16.6 letters at 12 months (p = 0.031). Mean CMT at baseline was 406 ± 105 µm, which decreased to 329 ± 108 µm (p = 0.002). At 12 months, 44.4% of eyes with total injection number < 5 and 42.9% with injection number ≥ 5 achieved a gain in vision that was 10 letters or more. A total of 5 injections or more did not lead to a better visual gain in comparison with only 3-4 injections (p = 0.71), and both had similar number of supplementary treatments (p = 0.43). Monthly reinjections of ranibizumab resulted in a lower likelihood of visual loss of 10 or 15 letters (p = 0.019 and 0.015, respectively, adjusted for age, baseline vision, severity of diabetic retinopathy and the presence of previous treatments); however, supplementary macular lasers, PSTA or ranibizumab without monthly reinjections did not (all p > 0.05). The average number of injections was 4.3 ± 1.0.

CONCLUSION

Treatment for DME with at least three monthly ranibizumab loading injections, with or without other supplementary treatments, is effective at 12 months thereafter. Two monthly reinjections of ranibizumab, while not significantly increasing vision, may have a role in preventing visual loss.

[Anti-VEGF therapy resistance in neovascular age-related macular degeneration]

With account to the increase in the elderly population in most of the developed countries, the WHO defines age-related macular degeneration (AMD) as one of the main causes of blindness in the world. A large percentage of disability is accounted for by exudative, or neovascular, form of AMD. Today, a total of 5 anti-VEGF drugs exist that are recommended for treatment of exudative AMD: pegaptanib, ranibizumab, bevacizumab, aflibercept, and conbercept. Despite significant progress in the treatment of neovascular AMD yielded by the introduction into clinical practice of anti-VEGF drugs, some patients report a lack (down to complete lack) of response with standard treatment patterns and even a decrease in treatment efficacy after repeated intravitreal injections.

Ranibizumab treatment history as predictor of the switch-response to aflibercept: evidence for drug tolerance

Purpose

To investigate whether tolerance to the anti-VEGF drug, ranibizumab, develops after drug exposure and to determine whether the history of treatment with ranibizumab prior to refractoriness can predict the post-switching responses to aflibercept.

Methods

We retrospectively investigated neovascular age-related macular degeneration patients refractory to ranibizumab (intra- or subretinal fluid despite monthly injections for ≥6 months) who were switched to aflibercept and were followed up for at least 12 months on each of ranibizumab and aflibercept. Baseline characteristics and ranibizumab and aflibercept treatment history (number of injections during the first year and central retinal thickness [CRT]) were analyzed by univariate and multivariate correlation analyses.

Results

Ninety-eight eyes (88 patients, 70% females, mean age 77.5 years), including a high proportion of eyes with pigment epithelium detachment (63%), were treated with a mean of 26.2 injections during 36.8 months before switching to aflibercept. The number of ranibizumab injections required in the first year (p=0.0002) and the presence of pigment epithelium detachment (p=0.025) predicted the number of post-switching aflibercept injections required. The post-switching CRT change was predicted by the CRT increase from Month 3 to the switch time point (p<0.0001). Moreover, the CRT change correlated with the visual acuity benefit post-switching (p=0.038 and p=0.004, at 3 and 12 months post-switching, respectively).

Conclusion

Ranibizumab treatment history before switching to aflibercept correlates with the post-switching response in terms of the number of drug injections needed and CRT. Thus, drug tolerance does indeed exist and this might help to identify switching candidates.

A Prospective Randomized Comparative Dosing Trial of Ranibizumab In Bevacizumab-Resistant Diabetic Macular Edema: The REACT Study

Purpose

To assess the efficacy of ranibizumab for persistent diabetic macular edema (DME) previously treated with bevacizumab and compare monthly vs treat-and-extend (TAE) dosing.

Design

12-month, open-label, prospective randomized comparative dosing study.

Participants

27 participants with persistent foveal-involving DME recently treated with bevacizumab.

Methods

All subjects were to receive three initial monthly 0.3 mg ranibizumab injections before randomization to monthly (n=15) or TAE (n=12) injection protocols over 12 months. Treatment interval was extended by two weeks up to a maximum interval of 12 weeks in the TAE group if central subfield thickness (CST) was ≤ 300 μm or complete absence of intraretinal or subretinal fluid on the macular cube was observed. Follow-up interval was decreased by 2 weeks if CST increased above 300 μm with associated intraretinal and/or subretinal fluid.

Main Outcome Measures

Change in Early Treatment of Diabetic Retinopathy Study (ETDRS) best corrected visual acuity (BCVA), CST, adverse events.

Results

Prior to study enrollment, subjects received an average of 8.6 bevacizumab injections. At month 12, mean ETDRS BCVA improved by + 5.3 letters (p<0.05) and mean CST decreased by -99.6 μm (p<0.01) in all patients. At study exit, 18.5 % of subjects gained ≥ 3 lines of vision and 3.7% of subjects lost ≥ 3 lines. Patients treated via the TAE protocol gained +8.4 letters and decreased CST by -120.2 μm whereas those treated by monthly injection gained +2.7 letters and decreased CST by -83.1 μm at month 12.

Conclusions

Following conversion to ranibizumab in eyes with persistent DME refractory to bevacizumab, significant functional and anatomic improvements were noted. Visual and anatomical outcomes were similar in TAE and monthly treatment protocols.

Evaluation of contrast sensitivity and other visual function outcomes in diabetic macular edema patients following treatment switch to aflibercept from ranibizumab

Purpose

This study aims to investigate changes in contrast sensitivity (CS), visual acuity (VA), central retinal thickness (CRT), and vision-related quality of life in subjects with recalcitrant diabetic macular edema switched from long-term ranibizumab treatment to aflibercept.

Patients and methods

In this prospective, investigator-masked, single-center study, 40 patients with persistent fluid, despite previous ranibizumab treatment, were switched to aflibercept with 5 consecutive monthly doses. The primary outcome was mean change from baseline to week 20 in Pelli–Robson CS. Secondary outcomes were mean change from baseline in best-corrected VA (BCVA), CRT, and National Eye Institute 25-Item Visual Function Questionnaire score.

Results

Fifty eyes (baseline VA >6/30) were evaluated. A median of 21.1±11.9 (range 5–55) ranibizumab injections were administered prior to initiation of aflibercept. Mean CS improved from 1.40±0.14 log units at baseline to 1.46±0.15 log units at week 20 (P<0.001). VA improved with mean logarithm of the minimum angle of resolution BCVA of 0.33±0.19 at baseline compared with logarithm of the minimum angle of resolution BCVA of 0.28±0.16 at week 20 (P=0.0016). Mean CRT decreased from 324±85 to 289±61 µm (P<0.001). Twenty-two (55%) patients experienced an overall improvement in National Eye Institute 25-Item Visual Function Questionnaire score. Interestingly, an association was found between changes in CS and change in CRT (r²=0.385, P<0.001) and between changes in BCVA and change in CRT (r²=0.092, P=0.032).

Conclusion

Switching from ranibizumab to aflibercept in patients with recalcitrant diabetic macular edema resulted in an improvement in all measured metrics, including CS, VA, and CRT. A majority of patients also indicated an improvement in vision-related quality of life. The finding of a stronger relationship between changes in CRT and CS compared with changes in CRT and BCVA suggests that the inclusion of CS as an endpoint may yield a more complete understanding of visual outcomes than that obtained by using VA alone.

All Types of Age-related Macular Degeneration in One Patient

Herein, we describe a neovascular age-related macular degeneration patient with retinal angiomatous proliferation (RAP) and polypoidal choroidal vasculopathy (PCV) coexisting in the same eye at the time of diagnosis. A 55-year-old woman presented with a history of decreased vision in her left eye. Fundoscopy, fluorescein and indocyanine green angiography, and optical coherence tomography imaging revealed RAP and PCV lesions in her left eye at first diagnosis. The patient received intravitreal ranibizumab therapy but developed tachyphylaxis after the first dose despite having three monthly doses. Switching to intravitreal aflibercept injection in our case resulted in anatomic and functional improvement.

Switching Anti-VEGF Drugs in the Treatment of Diabetic Macular Edema

Since their introduction in the late 2000s, anti-vascular endothelial growth factor (VEGF) agents have become the first-line choice for center-involved diabetic macular edema (DME). Even with its proven effectiveness, there are still cases that do not respond satisfactorily. In those cases, a treatment option is to change to another anti-VEGF drug. In this paper, the authors review studies on switching between different anti-VEGF drugs in the treatment of persistent DME. An extensive bibliographic review was done using PubMed, Embase, and Scopus. Fourteen studies published from March 2010 to April 2017 reporting switching from anti-VEGF drugs in DME treatment were included. All reported good anatomical results after conversion; however, visual acuity outcomes showed great variability between publications. Therefore, switching to other anti-VEGFs in patients with DME not responding to previous anti-VEGF therapy may be an option, but the results are still not well-known due to a lack of randomized clinical trials. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:748-754.].

Two-Year Outcome of Aflibercept in Patients with Pigment Epithelial Detachment due to Neovascular Age-Related Macular Degeneration (nAMD) Refractory to Ranibizumab

Purpose

To evaluate the response of intravitreal aflibercept injection (IAI) in eyes with detachment of retinal pigment epithelium (DEP) secondary to nAMD refractory to monthly ranibizumab.

Patients and Methods

This is a retrospective, multicenter study. All patients received 3 IAI then treated as needed every 4 weeks for 12 months. During the second year, the eyes were treated with a treat- and-extend regimen.

Results

Forty-four eyes were included. Best-corrected visual acuity improved significantly after the loading phase (3.1 ± 6.4 letters) and at 6 months (2.8 ± 6.4 letters), but change was not significant at 1 year and 2 years. The height of the DEP was significantly decreased at 3 months and 6 months, but the difference did not reach statistical difference at 1 and 2 years. Rate of eyes with complete resolution of exudation was 59% after the loading phase and 34.3% at 2 years. Mean interval of anti-VEGF injection was extended from 31 ± 2.6 days to 61 ± 5 days after conversion.

Conclusions

Aflibercept intravitreal injection in patients with fibrovascular DEP due to nAMD who respond poorly to monthly ranibizumab led to short-term functional and anatomical improvement. Reduction of intravitreal injection frequency was obtained until 2 years of follow-up.

The ocular toxicity and pharmacokinetics of simvastatin following intravitreal injection in mice

AIM

To investigate the retinal toxicity and pharmacokinetics of simvastatin intravitreally injected into mice.

METHODS

Forty-eight 6-8-week-old C57BL/6J mice were used in this study. Simvastatin was intravitreally injected into the right eye of each mouse; the left eye was injected with vehicle and was used as a control. Bilateral dark-adapted electroretinography (ERG) was performed 1 and 7d following injection. Histology was examined using a combination of light, fluorescence and electron microscopy. High-performance liquid chromatography (HPLC) was used to determine the decay in the retinal simvastatin concentration.

RESULTS

ERG revealed no significant changes in the simvastatin-injected eyes compared to control. Histologic studies showed normal retinal morphology in eyes injected with simvastatin up to a final vitreal concentration of 200 µmol/L. No significant changes in the number of photoreceptors, bipolar cells or ganglion cells were found. The retinal simvastatin concentration decayed exponentially, with a half-life of 1.92-2.41h.

CONCLUSION

Intravitreal injection of up to 200 µmol/L simvastatin produced no signs of adverse effects in the mouse retina. Simvastatin reaches the retina shortly after intravitreal injectionand has a short half-life.

Induction of vascular endothelial growth factor receptor expression in human umbilical vein endothelial cells after repeated bevacizumab treatment in vitro

AIM

To investigate the mechanism underlying the loss of responsiveness to anti-vascular endothelial growth factor (VEGF) treatment after repeated injections for choroidal neovascularization, VEGF and VEGF receptor (VEGFR) expressions were evaluated following repeated bevacizumab treatments in hypoxic human umbilical vein endothelial cells (HUVECs) in vitro.

METHODS

HUVECs were incubated under hypoxic conditions in two media of different bevacizumab concentrations (1.0 or 2.5 mg/mL) for 17h, and then in a new medium without bevacizumab for 7h. This procedure was repeated twice more. A culture with an identical volume of excipients served as the control. Cytotoxicity and cell proliferation were assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and Ki-67 assays, respectively. Levels of VEGF and VEGFR were assessed using enzyme-linked immunosorbent assay and Western blot respectively.

RESULTS

Cytotoxic effects were not reported for either bevacizumab concentration. Cell proliferation was not reduced after anti-VEGF treatments. VEGF level after single treatment was significantly higher than that of the control and after repeated treatments. Phosphorylated VEGFR-2 expression increased significantly after single and repeated bevacizumab treatments compared with the control. The 1.0 mg/mL bevacizumab induced significantly higher expressions of VEGFR-2 than the 2.5 mg/mL in single and repeated treatment groups.

CONCLUSION

Bevacizumab treatment of HUVECs elevated VEGFR expression in both single and repeated treatments, indicating a mechanism for the reduced efficacy of anti-VEGF therapy in ocular neovascular disorders.

Evaluation of Aflibercept Treatment Responses in Eyes with Bevacizumab/Ranibizumab-resistant Wet Age-related Macular Degeneration

Objectives:

To evaluate anatomic and functional results after switching from intravitreal bevacizumab or ranibizumab treatment to aflibercept for wet (neovascular) age-related macular degeneration.

Materials and Methods:

This retrospective study included 22 eyes of 22 patients resistant to treatment with at least 6 injections of bevacizumab or ranibizumab. The first three injections had been applied monthly, the others pro re nata (PRN). Outcome measures were follow-up period, injection number, best corrected visual acuity (BCVA), central retinal thickness (CRT) and pigment epithelial detachment (PED) height. Dosing regimen of aflibercept was determined PRN. The patients were examined monthly. In all visits, BCVA and optical coherence tomography results were assessed together and injections were applied according to these findings. Patients with at least three months of follow-up were included in the study.

Results:

Twenty-two eyes of 22 patients treated with bevacizumab or ranibizumab were switched to aflibercept therapy. Seven patients had serous PED and 4 patients had fibrovascular PED. The mean follow-up periods for these groups were 20.59±6.76 months and 8.68±3.79 months, respectively. The mean injection numbers were 10.5±3.61 vs 4.54±1.56. Statistically significant reductions were noted in CRT (533.86±164.06 µm vs 412.04±143.86 µm, p<0.05). BCVA levels were almost equal before and after switching (0.18±0.17 vs 0.18±0.14). Serous and fibrovascular PED heights decreased suboptimally from 460±281.51 µm to 282.42±175.76 µm (p>0.05) for serous PEDs and 251.25±43.85 µm to 225.75±73.09 µm (p>0.05) for fibrovascular PEDs.

Conclusion:

Switching to aflibercept resulted in significant improvement in CRT, but not in BCVA or PED heights.

Switch to aflibercept or ranibizumab after initial treatment with bevacizumab in eyes with neovascular AMD

Background

To evaluate changes in central macular thickness (CMT) and visual outcome in patients with neovascular age-related macular degeneration (AMD) treated initially with bevacizumab and subsequently switched to either aflibercept or ranibizumab.

Methods

Observational clinical study was performed. We measured the structural outcome (CMT on SD-OCT; μm) and the visual outcome (best corrected visual acuity (BCVA); logMAR), as follows: before treatment (at baseline), following bevacizumab treatment (switch follow-up) and after switching from bevacizumab to aflibercept- or ranibizumab treatment (final follow-up, AG/, RG).

Results

From a total of 96 eyes treated with intravitreal injections of bevacizumab (10.5 ± 7.6 (mean ± SD)), 58 eyes switched to aflibercept (6.5 ± 3.9; AG) and 38 eyes switched to ranibizumab (7.1 ± 5.3; RG) (≥ 3 injections, each). In addition, these eyes were compared to 37 eyes under bevacizumab monotherapy.

Primary outcome: In the AG, the CMT decreased slightly from 430 ± 220 μm at baseline to 419 ± 212 μm at switch follow-up (p = 0.86), but decreased significantly to 318 ± 159 μm at final follow-up, AG (p < 0.0001). In the ranibizumab group (RG), the CMT increased from 396 ± 174 μm at baseline to 499 ± 333 μm at switch follow-up (p = 0.012), but decreased significantly to 394 ± 202 μm at final follow-up, RG (p = 0.007).

Secondary outcome: In the AG, the mean BCVA worsened from logMAR 0.57 ± 0.33 at baseline to 0.63 ± 0.30 at switch follow-up and improved slightly to 0.53 ± 0.71 at final follow-up, AG (p = 0.46). In the RG, mean BCVA worsened from 0.57 ± 0.28 at baseline to 0.64 ± 0.31 at switch follow-up and improved slightly to 0.60 ± 0.36 at final follow-up, RG (p = 0.64).

Conclusion

Switching from bevacizumab to either aflibercept, or ranibizumab, has a strong anatomical effect in eyes with neovascular AMD. Nevertheless, even if the switch to aflibercept shows a minimal functional benefit over that to ranibizumab, visual prognosis remains limited.

Efficacy and safety of a fixed bimonthly ranibizumab treatment regimen in eyes with neovascular age-related macular degeneration: results from the RABIMO trial

PURPOSE

To evaluate prospectively the efficacy and safety of a fixed bimonthly ranibizumab treatment regimen (RABIMO) in eyes with neovascular age-related macular degeneration (nAMD) and to compare these results with a pro re nata (PRN) treatment scheme.

METHODS

This was a 12-month, phase IV, single center, randomised, non-inferiority study. Following three initial monthly injections, patients were randomised to receive either ranibizumab bimonthly (RABIMO group) or ranibizumab PRN (PRN group) (n = 20 each). Main outcome measures were best-corrected visual acuity (BCVA), central retinal thickness (CRT), number of injections, and adverse events (AEs).

RESULTS

BCVA [median (interquartile range, IQR)] increased significantly in both groups after 12 months [RABIMO group +8.5 (14); PRN group +6.5 (16) ETDRS letters] when compared to baseline (p < 0.0001; p = 0.0085). At month 12, the RABIMO treatment regimen was non-inferior to the PRN scheme (∆BCVA = 3.5 ETDRS letters; p < 0.0001). CRT was significantly reduced in both groups after the 12-month study period (p < 0.0001 each), with no significant difference between groups (p = 0.6772). Number of overall injections [median (IQR)] was 8 (0) in the RABIMO versus 4 (5) in the PRN group (p = 0.0037). Three patients in the RABIMO group received one additional unscheduled injection. We observed no significant differences between groups in the number of patients with reported SAEs/AEs (RABIMO group n = 6/15; PRN group n = 7/13) (p = 0.7357/p = 0.4902).

CONCLUSIONS

We found no evidence of significant functional or anatomical differences between the RABIMO and PRN treatment regimens. However, the RABIMO group's number of injections was twice as high as the PRN group's (protocol-driven). In light of potential side effects, the fixed bimonthly treatment regimen might not be advisable for routine clinical care, but it might be a worthwhile treatment option if monthly monitoring is not possible. Eudra-CT number: 2009-017324-11.

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.

A 24-Month Evaluation of Aflibercept for Wet Age-Related Macular Degeneration in Patients Previously Receiving Ranibizumab or Bevacizumab

PURPOSE

To report the 24-month results and predictive factors for outcomes in patients transitioned from other anti-vascular endothelial growth factor agents to aflibercept for the treatment of exudative age-related macular degeneration (AMD).

DESIGN

A prospective, single arm, investigator-initiated study.

PARTICIPANTS

A total of 24 patients participated in the study and 87.5% (n = 21) completed the 24 month assessments. Patients were included if they had an active exudative AMD confirmed by fluorescein angiography, presence of fluid on spectral-domain optical coherence tomography (OCT) or new hemorrhage on clinical examination, Electronic Early Treatment Diabetic Retinopathy Study vision of 25 to 80 letters (Snellen equivalent of approximately 20/25-20/320), prior bevacizumab or ranibizumab injections within 3 months of enrollment, and an initial response on OCT defined as a decrease of retinal edema and/or subretinal fluid to anti-vascular endothelial growth factor injections.

METHODS

Patients were treated the first 3 months with 2 mg of intravitreal aflibercept monthly, followed by a fixed bimonthly schedule for 24 months. At each study visit, visual acuity and a spectral-domain OCT scanning of both eyes were performed.

MAIN OUTCOME AND MEASURES

The mean absolute change from baseline in central subfield thickness at month 24, mean change from baseline in best-corrected visual acuity (BCVA) score, change from baseline in macular volume, and cube average thickness by spectral-domain OCT. Additionally, predictive factors associated with final visual and anatomic outcomes at month 24.

RESULTS

A mean decrease in central subfield thickness of -41 μm (P = 0.004) was observed with a mean increase in ETDRS BCVA of +10.4 letters (P < 0.001). At study entry, BCVA was a significant predictive factor for BCVA change at month 24 (rho = -0.59; P = 0.003). Also, the duration between AMD diagnosis and study entry was a significant factor for central subfield thickness change at month 24 (rho = -0.51; P = 0.011).

CONCLUSIONS

In nonnaïve patients with active exudative AMD, treatment with a fixed intravitreal aflibercept dosing regimen for 24 months demonstrated sustained improvements in anatomy and vision in patients transitioned from other anti-vascular endothelial growth factor agents and stability when compared with 12-month outcomes. Patients who benefited most were those with worse vision at entry and longer duration of disease.

PIGMENT EPITHELIAL DETACHMENT RESPONSE TO AFLIBERCEPT IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION REFRACTORY TO RANIBIZUMAB: Time Course and Drug Effects

PURPOSE

To investigate the time course of pigment epithelium detachment (PED) height and its change after anti-vascular endothelial growth factor switch from ranibizumab to aflibercept in neovascular age-related macular degeneration.

METHODS

This retrospective study included 60 eyes of 50 consecutive patients with neovascular age-related macular degeneration who showed refractory intraretinal or subretinal fluid (≥9 months) despite monthly ranibizumab treatment and an associated PED (height ≥150 μm). The treatment was switched to aflibercept, and patients were followed-up for at least 9 months. Data on the height and type of PED, exudative fluid, and best-corrected visual acuity were collected at four different time points (two before and two after the drug switch).

RESULTS

The maximal PED height was significantly decreased over time, both under ranibizumab and aflibercept treatment. However, the reduction was significantly greater during the 3 months after the switch to aflibercept, due to two outliers. Visual acuity remained stable. Complete resolution of intraretinal or subretinal fluid was observed in 9 cases (15%) at 3 months after switch, allowing for treatment interval extension.

CONCLUSION

Maximal PED height continuously decreased over time. Switching the intravitreal anti-vascular endothelial growth factor medication from ranibizumab to aflibercept had a significantly stronger short-term effect on PED height reduction, without changes in visual acuity.

Evaluating Efficacy of Aflibercept in Refractory Exudative Age-Related Macular Degeneration With OCT Segmentation Volumetric Analysis

BACKGROUND AND OBJECTIVE

To use automated segmentation software to analyze spectral-domain optical coherence tomography (SD-OCT) scans and evaluate the effectiveness of aflibercept (Eylea; Regeneron, Tarrytown, NY) in the treatment of patients with exudative age-related macular degeneration (AMD) refractory to other treatments.

PATIENTS AND METHODS

Retrospective chart review of 16 patients refractory to bevacizumab (Avastin; Genentech, South San Francisco, CA)/ranibizumab (Lucentis; Genentech, San Francisco, CA) treatment was conducted. Visual acuity, central foveal thickness (CFT), maximum fluid height, pigment epithelial detachment (PED) volume, sub-retinal fluid (SRF) volume, fluid-free time interval, and adverse effects were evaluated. Automated segmentation analysis was used to quantify improvement.

RESULTS

With aflibercept treatment, there was a statistically significant improvement in visual acuity by 1 line (P = .020), in CFT by 74.02 µm (P = .001), and in maximum fluid height by 31.9 µm (P= .011). Total PED and SRF volume also decreased significantly by 1.50 µm(3) × 10(8) µm(3) (P = .013). Anatomic improvement was confirmed by automated segmentation analysis.

CONCLUSION

This study demonstrates utility of automated segmentation software in quantifying anatomic improvement with aflibercept treatment in exudative AMD refractory to other anti-vascular endothelial growth factor treatments.

Response to Bevacizumab after Treatment with Aflibercept in Eyes with Neovascular AMD

Purpose

To study the visual outcome and change in central macular thickness (CMT) in patients with neovascular age-related macular degeneration (AMD) who were previously treated with aflibercept (VEGF Trap-Eye, Eylea) and were subsequently switched to bevacizumab (Avastin).

Methods

In this observational analysis, 19 eyes initially treated with at least 3 injections of bevacizumab after initial treatment with at least 3 injections of aflibercept are reported. Outcome measures were Snellen visual acuity (best-corrected visual acuity (BCVA) and CMT measured by spectral-domain optical coherence tomography.

Results

A total of 19 eyes initially treated with 6.5 ± 2.8 intravitreal injections of aflibercept were switched to 5.4 ± 3.2 injections of bevacizumab. Median BCVA decreased from 20/94 to 20/113 after aflibercept and increased slightly to 20/101 after bevacizumab (p = 0.84, Friedman test). Of all 19 eyes, 36.8% achieved gain in visual acuity of more than 1 line and 21.1% of more than 3 lines. The CMT decreased slightly from 433 ± 229 μm at baseline to 367 ± 198 μm after aflibercept treatment (p = 0.18, Wilcoxon test) and decreased statistically significantly to 335 ± 184 μm after bevacizumab treatment (p = 0.0065, Wilcoxon test).

Conclusions

Switching from aflibercept to bevacizumab treatment has an equivalent anatomical effect in eyes with neovascular AMD as switching from bevacizumab to aflibercept. Therefore, switching back to bevacizumab might represent a reasonable therapy strategy to overcome tachyphylaxis during long-term monotherapy with aflibercept.

Tristetraprolin regulates the decay of the hypoxia-induced vascular endothelial growth factor mRNA in ARPE-19 cells

The aim of the present study was to investigate the effects of tristetraprolin (TTP) on the vascular endothelial growth factor (VEGF) mRNA and protein expression levels in retinal pigment epithelial cells under hypoxic conditions, and to consider the possibility of using TTP as a novel treatment tool for neovascular age‑related macular degeneration (AMD). Overexpression of TTP reduced the expression and secretion levels of VEGF in ARPE‑19 cells under hypoxic conditions. TTP destabilized the VEGF mRNA by binding to adenosine and uridine‑rich elements regions in its 3'‑untranslated region. Furthermore, conditioned medium (CM) from TTP‑overexpressing ARPE‑19 cells suppressed the tube formation in human umbilical vein endothelial cells compared with hypoxic CM. These findings indicate that regulation of TTP expression may be a promising therapeutic tool for neovascular AMD, however, further research is required.

Tenascin-C secreted by transdifferentiated retinal pigment epithelial cells promotes choroidal neovascularization via integrin αV

Tenascin-C is expressed in choroidal neovascular (CNV) membranes in eyes with age-related macular degeneration (AMD). However, its role in the pathogenesis of CNV remains to be elucidated. Here we investigated the role of tenascin-C in CNV formation. In immunofluorescence analyses, tenascin-C co-stained with α-SMA, pan-cytokeratin, CD31, CD34, and integrin α_V in the CNV membranes of patients with AMD and a mouse model of laser-induced CNV. A marked increase in the expression of tenascin-C mRNA and protein was observed 3 days after laser photocoagulation in the mouse CNV model. Tenascin-C was also shown to promote proliferation and inhibit adhesion of human retinal pigment epithelial (hRPE) cells in vitro. Moreover, tenascin-C promoted proliferation, adhesion, migration, and tube formation in human microvascular endothelial cells (HMVECs); these functions were, however, blocked by cilengitide, an integrin α_V inhibitor. Exposure to TGF-β2 increased tenascin-C expression in hRPE cells. Conditioned media harvested from TGF-β2-treated hRPE cell cultures enhanced HMVEC proliferation and tube formation, which were inhibited by pretreatment with tenascin-C siRNA. The CNV volume was significantly reduced in tenascin-C knockout mice and tenascin-C siRNA-injected mice. These findings suggest that tenascin-C is secreted by transdifferentiated RPE cells and promotes the development of CNV via integrin α_V in a paracrine manner. Therefore, tenascin-C could be a potential therapeutic target for the inhibition of CNV development associated with AMD.

Short-term effect of aflibercept on visual acuity and central macular thickness in patients not responding to ranibizumab and bevacizumab

PURPOSE

To analyze the clinical outcome of treatment with aflibercept in patients not responding to ranibizumab and bevacizumab.

METHODS

Retrospective review of 32 eyes from 30 consecutive patients with choroidal neovascularization (CNV) who showed no response to treatment with ranibizumab or bevacizumab and were switched to aflibercept. Visual acuity, central macular thickness (CMT) and presence or absence of intraretinal or subretinal fluid were analyzed before switching to aflibercept, after each of three uploading dose injections of aflibercept and 6, 8 and 10 weeks after the third aflibercept injection. All eyes had previous ranibizumab injections and the mean number of previous injections was 14.75 (± 7.38). Mean duration of previous anti-vascular endothelial growth factor (VEGF) treatment was 38 months (± 27.35 months).

RESULTS

Mean visual acuity before switching to aflibercept was 0.40 ± 0.30 logMAR. After the third injection visual acuity was 0.3 ± 0.3 logMAR and 10 weeks after the third injection it was 0.50 ± 0.20 logMAR. No significant differences were seen during treatment and follow-up. The mean CMT was 394 ± 118 µm at baseline, at follow-up (first, second and third, group week 6, group week 8 and group week 10) it was 317 ± 108 µm, 301 ± 99 µm, 292 ± 83 µm, 270 ± 78 µm, 340 ± 146 µm and 377 ± 92 µm, respectively. Significant reductions in CMT were seen between the first and third follow-up injections and at group week 8. Of the patients 59.4 % were complete non-responders to aflibercept.

CONCLUSION

Aflibercept results in improvement in CMT in non-responders to ranibizumab and bevacizumab as long as therapy is given continuously and can therefore be an alternative therapy.

Worsening anatomic outcomes following aflibercept for neovascular age-related macular degeneration in eyes previously well controlled with ranibizumab

Purpose

Antivascular endothelial growth factor injection is the mainstay of treating neovascular age-related macular degeneration (AMD). Previous studies have shown that switching treatment from ranibizumab to aflibercept led to an improvement in eyes with recalcitrant activity. Herein, we identify a unique subset of patients whose eyes with neovascular AMD were previously well controlled with ranibizumab injections were then worsened after being switched to aflibercept.

Methods

This is a retrospective interventional case series. Eyes with neovascular AMD, previously well controlled with monthly injections of ranibizumab, which then developed worsening of subretinal fluid after being switched to aflibercept were included.

Results

A total of 17 eyes were included. All eyes developed increased subretinal fluid when switched from ranibizumab to aflibercept. Fourteen patients were switched back to ranibizumab after a single injection of aflibercept and had subsequent rapid resolution of subretinal fluid. Three patients continued with monthly aflibercept injections for two subsequent months and demonstrated the persistence of the increased subretinal fluid until they were switched back to treatment with ranibizumab at which time the fluid resolved. No eye had persistent decline in visual acuity.

Conclusion

Switching from intravitreal ranibizumab to aflibercept in eyes with well-controlled neovascular AMD may result in worsening in a subset of patients and resolves when therapy is switched back to ranibizumab.

Deletion of miR-150 Exacerbates Retinal Vascular Overgrowth in High-Fat-Diet Induced Diabetic Mice

Diabetic retinopathy (DR) is the leading cause of blindness among American adults above 40 years old. The vascular complication in DR is a major cause of visual impairment, making finding therapeutic targets to block pathological angiogenesis a primary goal for developing DR treatments. MicroRNAs (miRs) have been proposed as diagnostic biomarkers and potential therapeutic targets for various ocular diseases including DR. In diabetic animals, the expression levels of several miRs, including miR-150, are altered. The expression of miR-150 is significantly suppressed in pathological neovascularization in mice with hyperoxia-induced retinopathy. The purpose of this study was to investigate the functional role of miR-150 in the development of retinal microvasculature complications in high-fat-diet (HFD) induced type 2 diabetic mice. Wild type (WT) and miR-150 null mutant (miR-150-/-) male mice were given a HFD (59% fat calories) or normal chow diet. Chronic HFD caused a decrease of serum miR-150 in WT mice. Mice on HFD for 7 months (both WT and miR-150-/-) had significant decreases in retinal light responses measured by electroretinograms (ERGs). The retinal neovascularization in miR-150-/--HFD mice was significantly higher compared to their age matched WT-HFD mice, which indicates that miR-150 null mutation exacerbates chronic HFD-induced neovascularization in the retina. Overexpression of miR-150 in cultured endothelial cells caused a significant reduction of vascular endothelial growth factor receptor 2 (VEGFR2) protein levels. Hence, deletion of miR-150 significantly increased the retinal pathological angiogenesis in HFD induced type 2 diabetic mice, which was in part through VEGFR2.

Predictors of Outcome in Patients with Neovascular Age-Related Macular Degeneration Switched from Ranibizumab to 8-Weekly Aflibercept

PURPOSE

The purpose of this study was to evaluate the outcomes over 12 months in patients with neovascular age-related macular degeneration (nAMD) with insufficient response to ranibizumab who were switched directly to 8-weekly fixed dosing of aflibercept without a loading phase.

DESIGN

Retrospective interventional study.

PARTICIPANTS

Consecutive patients with nAMD who were switched from pro re nata (PRN) intravitreal ranibizumab to 8-weekly fixed aflibercept because of persistent disease activity from November 1, 2013, to September 30, 2014, were included.

METHODS

Demographic data, visual acuity (VA), and spectral-domain optical coherence tomography characteristics over time were evaluated to determine the prognostic indicators of final visual outcome at 12 months.

MAIN OUTCOME MEASURES

The VA, central subfield thickness (CST), presence of macular fluid at month 12 compared with baseline, and the definition of prognostic indicators of final visual outcome at month 12.

RESULTS

A total of 431 patients (447 eyes) were included in this study. There was no statistically significant difference in VA between baseline and month 12 (P = 0.79), whereas the CST significantly decreased at month 12 compared with baseline (P < 0.001). At the 12-month follow-up, 48.3% of eyes had no macular fluid compared with 8.5% at baseline. The mean number of injections at month 12 was 6.8±1.75. Poor prognostic indicators included increasing age, increasing CST, the presence of intraretinal fluid, pigment epithelial detachment, and subfoveal thickening.

CONCLUSIONS

Patients who have not yet "responded" to PRN ranibizumab seem to exhibit retinal dehydration after switching to aflibercept, whereas there was no demonstration of VA benefit. Baseline features at the point of switching can independently predict outcomes.

Resistance to anti-VEGF therapy in neovascular age-related macular degeneration: a comprehensive review

As a progressive chronic disease, age-related macular degeneration (AMD) is the leading cause of irreversible vision impairment worldwide. Experimental and clinical evidence has demonstrated that vascular endothelial growth factor (VEGF) plays a vital role in the formation of choroidal neovascularization. Intravitreal injections of anti-VEGF agents have been recommended as a first-line treatment for neovascular AMD. However, persistent fluid or recurrent exudation still occurs despite standardized anti-VEGF therapy. Patients suffering from refractory or recurrent neovascular AMD may develop mechanisms of resistance to anti-VEGF therapy, which results in a diminished therapeutic effect. Until now, there has been no consensus on the definitions of refractory neovascular AMD and recurrent neovascular AMD. This article aims at clarifying these concepts to evaluate the efficacy of switching drugs, which contributes to making clinical decision more scientifically. Furthermore, insight into the causes of resistance to anti-VEGF therapy would be helpful for developing possible therapeutic approaches, such as combination therapy and multi-target treatment that can overcome this resistance.

Aflibercept in persistent neovascular AMD: comparison of different treatment strategies in switching therapy

PurposeTo evaluate the effects of aflibercept administered according to a pro re nata (PRN) or Fixed Regimen to patients with neovascular AMD and persistent intraretinal/subretinal fluid (IRF/SRF) despite three consecutive ranibizumab injections.MethodsPatients were switched to aflibercept injection (IVA) administered according to a PRN or to a fixed regimen for 1 year in two different retina centers. At baseline each patient underwent a complete ophthalmologic evaluation, including best-corrected visual acuity assessment (BCVA ETDRS chart), fluorescein, and indocyanine green angiography and OCT.ResultsEach group included 36 eyes. After 1 year the PRN group showed BCVA stabilization (63 vs 60 letters, P=0.33), whereas fixed regimen group showed significant BCVA improvement (68 vs 71, P=0.008). The median central retinal thickness decreased by 94 μm in the PRN (P=0.002) and by 148 μm in the fixed regimen group (P≤0.001). Complete IRF/SRF reabsorption was found in 58% of eyes in the PRN and in 42% of eyes in the fixed regimen group. At 1-year visit, the percentage of eyes with pigment epithelium detachment did not significantly decrease, but a height reduction was recorded in both groups. The median number of IVA was 3.5 in the PRN and 7 in the fixed regimen group.ConclusionThe switch to aflibercept with both treatment strategies enabled improvement in morphological parameters and stabilization of visual acuity. BCVA improvement and reduction in vision loss with reduction in retinal thickness, fluid and PED height was achieved with the fixed regimen in previously treated nAMD after 1 year.

The short-term effects of aflibercept on the size of choroidal neovascularization lesion in treatment-resistant neovascular age-related macular degeneration as determined by spectral-domain optical coherence tomography

BACKGROUND AND OBJECTIVES

To evaluate the changes in the size of choroidal neovascularization (CNV) lesion using spectral domain-optical coherence tomography (SD-OCT) in patients with treatment-resistant neovascular age-related macular degeneration (AMD) who were switched from ranibizumab to aflibercept.

MATERIALS AND METHODS

In this prospective case-series, 33 eyes of 30 patients with treatment-resistant neovascular AMD were included. Treatment-resistant neovascular AMD was defined as choriodal neovascularization secondary to AMD determined by subretinal fluid and/or intraretinal fluid/cysts after more than 6 months of monthly ranibizumab therapy. Enrolled eyes were received intravitreal aflibercept injections at weeks 0, 4, and 8. Maximum area of CNV lesion in the cross-sectional area in the B-scan was measured using Heidelberg Eye Explorer software. The same cross-sectional sections containing maximum area of CNV lesion were used during the follow-up. CNV subtypes were determined based on fluorescein angiography images prior to ranibizumab therapy. Main outcome measures were changes in best-corrected visual acuity (BCVA), central subfield thickness (CST), and area of CNV lesion.

RESULTS

There were five classic (15%), seven minimally classic (21%), and 21 occult subtypes of CNV (64%). Four weeks after the third injection, BCVA improvement and reduction of the retinal thickness in nine standard ETDRS subfields were significant (both P < 0.001). Regarding and regardless of CNV subtypes, mean area of CNV lesion decreased significantly at final visit. Overall, a dry macula was achieved in 21 eyes (64%) and 12 eyes (36%) showed decreased or unchanged edema.

CONCLUSIONS

Switching to aflibercept seems to result in reduction of CNV lesion area in short-term follow-up of patients with treatment-resistant neovascular AMD. Lasers Surg. Med. 48:668-677, 2016. © 2016 Wiley Periodicals, Inc.

A Meta-Analysis of Studies Evaluating Visual and Anatomical Outcomes in Patients with Treatment Resistant Neovascular Age-Related Macular Degeneration following Switching to Treatment with Aflibercept

With the introduction of aflibercept, eyes with neovascular age-related macular degeneration (AMD) not responding well to injections of ranibizumab or bevacizumab can be switched to treatment with aflibercept. We carried out a meta-analysis to analyze all available evidence of visual and anatomical outcomes of eyes with resistant neovascular AMD switched to aflibercept at six months. Data from seven retrospective and prospective studies looking at change in best corrected visual acuity (BCVA) and central retinal thickness (CRT) were included. Weighted mean difference (WMD) and 95% CI were estimated using the standardized mean change method. The overall results of the meta-analysis showed a small but statistically significant improvement in BCVA six months following treatment switch to aflibercept (WMD 0.142, 95% CI 0.006 to 0.28; p = 0.04), and the effect was more significant in data gathered from prospective studies (WMD 0.407, 95% CI 0.023 to 0.791, p = 0.038). There was a significant improvement in CRT following treatment switch to aflibercept (WMD −0.36, 95% CI −0.485 to −0.235; p < 0.0001). Our meta-analysis indicates that following treatment switch to aflibercept patients may have a significant improvement in CRT with stabilization or even some improvement in their visual acuity.

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.

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

PURPOSE

The recent introduction of anti-VEGF drugs has widely changed the prognosis of exudative age-related macular degeneration (AMD), even if a variable percentage of patients showed an insufficient response. Aflibercept is a new anti-VEGF drug approved by FDA for the treatment of exudative AMD with a wider binding capacity than either bevacizumab or ranibizumab. Therefore, the purposes were as follows: (i) to report anatomical and functional outcomes of switching from bevacizumab/ranibizumab to aflibercept previously described in the scientific literature, (ii) to hypothesize the possible pathophysiological mechanisms of the resistance and tachyphylaxis to anti-VEGF drugs, and (iii) to suggest possible clinical actions to increase the chances of success for such difficult cases.

METHODS

We reviewed the available scientific literature in Medline, Cochrane database, Current Contents, PubMed, and cross-referencing from identified articles, regarding the treatment of exudative AMD patients refractory to bevacizumab and/or ranibizumab and switched to aflibercept monotherapy. We included in this review all the cases in which the diagnosis of refractory or resistant exudative AMD was properly made, and the results of at least one aflibercept injection were described.

FINDINGS

We reported the outcomes of 21 papers for a total of 1066 eyes affected by exudative AMD resistant to previous anti-VEGF drug injections and switched to aflibercept. Enrolled reports were divided into two groups: 5 prospective reports and 16 retrospective reports. All the reported papers conclude their analysis, stating that switching from bevacizumab/ranibizumab to aflibercept injections can improve outcomes successfully in refractory neovascular AMD patients.

IMPLICATIONS

Analysis of the papers reported in this review demonstrates that switching from bevacizumab/ranibizumab to aflibercept injections can improve outcomes successfully in refractory neovascular AMD patients. The mechanism for these effects is not yet completely understood.

Aflibercept Treatment for Neovascular Age-related Macular Degeneration and Polypoidal Choroidal Vasculopathy Refractory to Anti-vascular Endothelial Growth Factor

PURPOSE

To report the results of switching treatment to vascular endothelial growth factor (VEGF) Trap-Eye (aflibercept) in neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) refractory to anti-VEGF (ranibizumab and bevacizumab).

METHODS

This is a retrospective study involving 32 eyes from 29 patients; 18 were cases of neovascular AMD and 14 were cases of PCV. The best-corrected visual acuity (BCVA) and central macular thickness (CMT) of spectral-domain optical coherence tomography were evaluated.

RESULTS

BCVA and CMT improved from 0.58 to 0.55 (p = 0.005) and from 404 to 321 µm (p < 0.001), respectively, after switching to aflibercept. The 14 eyes that received 6 or more aflibercept injections remained stable at 0.81 to 0.81 and 321 to 327 µm (p = 1.0, 0.29), respectively, after 3 aflibercept injections. The 10 eyes that received 3 or more bevacizumab injections after 3 or more aflibercept injections worsened, from 0.44 to 0.47 and from 332 to 346 µm (p = 0.06, 0.05), respectively. The results showed similar improvement of BCVA and CMT in neovascular AMD and PCV.

CONCLUSIONS

Aflibercept seems to be effective for improvement and maintenance of BCVA and CMT for neovascular AMD and PCV refractory to anti-VEGF. Switching from aflibercept back to bevacizumab treatment may not be a proper strategy.

Rescue effects of intravitreal aflibercept in the treatment of neovascular age-related macular degeneration

We report the rescue results of intravitreal aflibercept in patients with treatment-resistant neovascular age-related macular degeneration (AMD). We retrospectively analyzed eyes with neovascular AMD resistant to posterior subtenon triamcinolone, intravitreal ranibizumab, and/or bevacizumab treatment in a tertiary medical center in middle Taiwan between December 2013 and October 2014. We then switched treatment to 2.0 mg aflibercept. The main outcome included changes in best-corrected visual acuity and central foveal thickness measured by optical coherence tomography during monthly follow-up. There were 204 patients with neovascular AMD, and the percentage of refractory cases was 1.96% (4 of 204 cases). Our study included five eyes of four patients that were resistant to multiple treatments and subsequently switched to aflibercept. The mean age was 71.25 ± 11.09 years (range 57–83 years). Treatments were on average 6.6 times previously. Upon switching to aflibercept treatment, the average central foveal thickness on optical coherence tomography was 505.6 ± 270.86 μm (range 150–815 μm). After aflibercept treatment, the average central foveal thickness was 192 ± 51.76 μm (range 149–274 μm). All patients showed anatomic improvement, and 80% of the eyes (4 of 5 eyes) had improved best-corrected visual acuity and 20% of the eyes (1 of 5 eyes) had stable visual acuity. Patients tolerated the treatment well without serious adverse events. This short-term study showed that intravitreal aflibercept was effective and safe in treatment-resistant neovascular AMD cases. However, analysis of more cases and long-term follow-ups are mandatory.

Short-term results of switchback from aflibercept to ranibizumab in neovascular age-related macular degeneration in clinical practice

PURPOSE

This work was undertaken to analyze the efficacy of switchback from aflibercept to ranibizumab in patients with neovascular age-related macular degeneration (nAMD) who had previously switched from ranibizumab to aflibercept.

METHODS

This retrospective double-center study included 45 patients with nAMD who were previously treated with ranibizumab, then aflibercept, and then ranibizumab again, regardless of the number of intravitreal injections received. The primary outcome was change in best-corrected visual acuity (BCVA) measured on the Early Treatment Diabetic Retinopathy Study ETDRS chart before (T0) and after (T1) the switch, and 3 months after the switchback (T2). Secondary outcomes included changes in central foveal thickness (CFT) measured at T0, T1, and T2, as analyzed on spectral-domain optical coherence tomography (SD-OCT), and the percentage of patients gaining five letters or better.

RESULTS

Forty-seven eyes of 45 patients were switched back from aflibercept to ranibizumab. The mean BCVA was 67.4 ± 13.4 at T0, 66.7 ± 14.4 at T1, and 68.2 ± 13.9 at T2. BCVA was significantly improved between T1 and T2 (p = 0.0230), but not between T0 and T1 (p = 0.5153) or between T0 and T2 (p = 0.4248). The mean CFT decreased from 317.8 μm ± 89.6 at T0 to 306.9 μm ±68.0 at T1, and to 291.2 μm ± 76.6 at T2. The decrease in CFT was not statistically significant between either T0 and T1 or T1 and T2, but was significant between T0 and T2, when compared before switch and after switchback (p = 0.0027). However, when considering eyes that received three or more consecutive intravitreal injections of aflibercept before switchback, the statistical significance between T1 and T2 was lost, although a trend towards significance remained (p = 0.06). Thirteen eyes (27.7 %) gained five letters or more (range, 5-15 letters) after switchback.

CONCLUSIONS

A short-term benefit of switchback from one anti-VEGF agent to another was observed in patients with nAMD who had shown no benefit from the initial switch.

Nanoengineering of therapeutics for retinal vascular disease

Retinal vascular diseases, including diabetic retinopathy, neovascular age related macular degeneration, and retinal vein occlusion, are leading causes of blindness in the Western world. These diseases share several common disease mechanisms, including vascular endothelial growth factor (VEGF) signaling, hypoxia, and inflammation, which provide opportunities for common therapeutic strategies. Treatment of these diseases using laser therapy, anti-VEGF injections, and/or steroids has significantly improved clinical outcomes. However, these strategies do not address the underlying root causes of pathology, and may have deleterious side effects. Furthermore, many patients continue to progress toward legal blindness despite receiving regular therapy. Nanomedicine, the engineering of therapeutics at the 1-100 nm scale, is a promising approach for improving clinical management of retinal vascular diseases. Nanomedicine-based technologies have the potential to revolutionize the treatment of ophthalmology, through enabling sustained release of drugs over several months, reducing side effects due to specific targeting of dysfunctional cells, and interfacing with currently "undruggable" targets. We will discuss emerging nanomedicine-based applications for the treatment of complications associated with retinal vascular diseases, including angiogenesis and inflammation.