INTRAVITREAL AFLIBERCEPT FOR CHOROIDAL NEOVASCULARIZATION DUE TO AGE-RELATED MACULAR DEGENERATION UNRESPONSIVE TO RANIBIZUMAB THERAPY

Phage Display Technology in Biomarker Identification with Emphasis on Non-Cancerous Diseases

In recent years, phage display technology has become vital in clinical research. It helps create antibodies that can specifically bind to complex antigens, which is crucial for identifying biomarkers and improving diagnostics and treatments. However, existing reviews often overlook its importance in areas outside cancer research. This review aims to fill that gap by explaining the basics of phage display and its applications in detecting and treating various non-cancerous diseases. We focus especially on its role in degenerative diseases, inflammatory and autoimmune diseases, and chronic non-communicable diseases, showing how it is changing the way we diagnose and treat illnesses. By highlighting important discoveries and future possibilities, we hope to emphasize the significance of phage display in modern healthcare.

Patient adherence to therapy after switch to aflibercept from bevacizumab or ranibizumab for treatment-refractory neovascular age-related macular degeneration

PURPOSE

Clinical trials have demonstrated that switching patients from intravitreal bevacizumab (IVB) or ranibizumab (IVR) to aflibercept (IVA) for treatment-refractory neovascular age-related macular degeneration (nAMD) can decrease the injection frequency. This study evaluated whether there was a difference in the rate of injections or nonadherent events after switching therapies.

METHODS

The study comprised a retrospective, cross-sectional analysis of patients treated for nAMD from 2010 to 2018 who received ≥3 intravitreal injections of IVB/IVR prior to switching to IVA because of treatment-refractory nAMD. The treatment index, outcomes, and adherence to treatment were compared between both treatment regimens.

RESULTS

Sixty-two patients (67 eyes) met inclusion criteria. There was no change in the treatment index (0.65 versus 0.66, P = 0.650) or the number of nonadherent events (33 versus 36, P = 0.760) after the switch from IVB/IVR to IVA. Central macular thickness (CMT) increased 7.7%±13.8% in eyes that had a nonadherent event (283±69 µm to 304±75 µm after resuming care, P = 0.039). There was no short-term impact on visual acuity (VA) for this subset of eyes (0.387±0.202 LogMAR versus 0.365±0.156 LogMAR, P = 0.636). Patients who had nonadherent events ended the study with similar VA compared with patients who had no treatment lapses (0.370±0.616 LogMAR versus 0.337±0.638 LogMAR, P = 0.843).

CONCLUSION

Switching from IVB/ IVR to IVA for treatment-refractory nAMD in a real-world setting does not reduce the treatment index or increase adherence to treatment. Although there were short-term anatomical effects resulting from missed treatments, VA remained stable.

Analysis of ocular fluid in patients with ranibizumab-recalcitrant neovascular age-related macular degeneration who have serum anti-ranibizumab antibodies

PURPOSE

To evaluate whether anti-drug antibodies (ADAs) are present in the ocular fluid of patients with ranibizumab-recalcitrant neovascular age-related macular degeneration (nAMD).

METHODS

Two serum ADA-positive ranibizumab-recalcitrant patients and two serum ADA-negative controls were recruited from patients with nAMD treated with ranibizumab monotherapy. Recalcitrance was defined as persistent fluid after ≥6 monthly ranibizumab injections. Serum and aqueous humor ADAs were detected by enzyme-linked immunosorbent assay and immunoprecipitation, respectively.

RESULTS

Two of 156 ranibizumab-treated patients were ADA-positive. The patients received six and 14 ranibizumab injections, respectively, up to 4 weeks prior to blood collection. The serum ADA concentration was estimated to be approximately 50,000 ng/mL. Neutralizing ADAs were confirmed in both samples. A specific band was detected by immunoprecipitation only in ADA-positive samples, consistent with the results of enzyme-linked immunosorbent assay. Based on an assessment of the degree of sensitivity of commercially available anti-ranibizumab antibodies, it was estimated that the immunoprecipitation method could detect ADA levels >30 ng. Nevertheless, ADAs were not detected in the aqueous humor of either the experimental or control group.

CONCLUSION

In the aqueous humor, ADAs are either not present or are present at a lower concentration than that which can be detected by immunoprecipitation. This presumably reflects the fact that blood ADA is the product of systemic circulation clearance through anterior elimination of intravitreal ranibizumab. Based on our results, ADAs do not return to the eye in sufficient quantities to interfere with the action of ranibizumab in the vitreous cavity.

Baseline characteristics and treatment response predictive of nAMD outcomes with ranibizumab therapy in treatment-naive patients: the RACER subgroup analysis

BACKGROUND

The Ranibizumab AMD Clinical Efficacy Study (RACER) conducted in treatment-naive adult Taiwanese patients with neovascular age-related macular degeneration (nAMD) suggested the importance of early and intensive dosing of ranibizumab for optimal treatment outcomes. This subgroup analysis aims to provide clinical information on treatment response that can potentially guide on maintaining the treatment or switching anti-VEGF agents in the real-world setting.

METHODS

Visual acuity (VA) and central retinal thickness (CRT) were assessed in the RACER subgroup population. Subgroup analysis sets were categorised based on: (1) baseline best-corrected VA (BCVA; ≤ 48 and > 48 letters); (2) baseline CRT (≤ 325 or > 325 μm); and (3) treatment response after three monthly initial injections: < or ≥ 5-letter gain in BCVA and reduction of < or ≥ 50 μm in CRT.

RESULTS

Patient age, sex, nAMD duration and number of ranibizumab injections did not differ significantly between the treatment subgroups. Poor baseline BCVA (≤ 48 letters) and baseline CRT severity (> 325 µm) were predictors of maximum BCVA gains (9.6 ± 12.9 letters [95%CI: 6.3 to 12.9] and 5.1 ± 18.3 letters [95%CI: - 0.5 to 10.8] at Months 3 and 12, respectively) and better CRT reductions (- 127.6 ± 104.2 µm and - 104.2 ± 107.4 µm at Months 3 and 12, respectively; both P < 0.001). For the subgroup showing favourable treatment improvement with BCVA gains ≥ 5 letters after three monthly initial injections, 75.6% of patients maintained follow-up at Month 12 with a mean of 6.5 ± 14.3 letter gains (95% CI: 1.2 to 11.7). The BCVA gains < 5-letter subgroup nevertheless had stable BCVA (0.4 ± 12.1 letter gains) and CRT (- 41.9 ± 61.2 µm) at Month 12, respectively. In the subgroup with ≥ 50 µm CRT reduction after three monthly initial injections, there are significantly higher BCVA improvements vs. the < 50 µm CRT reduction subgroup at Month 3 (5.0 ± 8.6 letter gains vs. 1.5 ± 11.6 letter gains, respectively; intergroup P = 0.005).

CONCLUSION

Lower baseline BCVA and higher baseline CRT were associated with BCVA gains and CRT reductions throughout the 12-month study period. Early CRT improvements after three monthly initial injections were associated with BCVA gains as early as Month 3.

Treatment of neovascular age-related macular degeneration: insights into drug-switch real-world from the Berlin Macular Registry

PURPOSE

Bevacizumab, ranibizumab, and aflibercept are commonly used to treat neovascular age-related macular degeneration (nAMD). The results of various interventional, mostly randomized head-to-head studies, indicate statistical non-inferiority of these three drugs. The results of these studies are often interpreted as the three drugs being freely interchangeable, resulting in some health systems to pressure ophthalmologists to preferentially use the less expensive bevacizumab. This study analyzes switching from aflibercept or ranibizumab to bevacizumab and back under real-world conditions in order to investigate the assumption of interchangeability of the drugs.

METHODS

Treatment data of IVT patients with diagnosed nAMD were extracted from the clinical Berlin Macular Registry database. Patients who underwent a drug switch from aflibercept or ranibizumab to bevacizumab were subject of this study. Statistical comparisons were pre-planned for best corrected visual acuity, central retinal thickness, macular volume, and length of injection interval. Additional endpoints were analyzed descriptively.

RESULTS

Mean visual acuity decreased from 0.57 ± 0.05 under aflibercept/ranibizumab to 0.68 ± 0.06 logMAR after the switch (P = 0.001; N = 63). CRT increased from 308 ± 11 µm to 336 ± 16 µm (P = 0.011; N = 63). About half of the subjects were switched back: visual acuity increased from 0.69 ± 0.08 logMAR to 0.58 ± 0.09 logMAR (N = 26). CRT decreased from 396 ± 28 to 337 ± 20 µm (N = 28).

CONCLUSION

The data provides real-world evidence that there is loss of visual acuity and an increase in retinal edema after switching to bevacizumab. Thus, the assumption of free interchangeability cannot be confirmed in this cohort.

A Real-World, Multicenter, 6-Month Prospective Study in Greece of the Effectiveness and Safety of Ranibizumab in Patients with Age-Related Macular Degeneration Who Have Inadequately Responded to Aflibercept: The “ELEVATE” Study

Purpose

Real-world evidence on short-term outcomes of ranibizumab in wet age-related macular degeneration (wAMD) following inadequate response to aflibercept is scarce. This study aimed to evaluate the functional and anatomic effects of switching to ranibizumab in cases of wAMD previously treated with aflibercept with inadequate response.

Patients and Methods

Prospective, observational study performed in eight ophthalmology hospital/private clinics in Greece, enrolling consented patients with active wAMD, ≥50 years-old, who had initiated ranibizumab ≥28 days and <2 months after their last aflibercept injection. Data were collected at enrollment, and at 1, 3 and 6 months post-treatment onset (post-baseline).

Results

Between September-2015 and November-2017, 103 eligible patients (56.3% females; mean age: 74.8±8.6 years) were consecutively enrolled. The age at AMD diagnosis in the study eye was 71.3±8.8 years. Aflibercept (median of 5 injections received over 11.3 months) had been discontinued for anatomical (in 69.9%) and/or functional (38.8%) reasons. At baseline (median: 24.3 months after wAMD diagnosis), choroidal neovascularization was occult in 69.1% of evaluable study eyes; 60.2% of the study eyes had pigment epithelial detachment (PED); 42.7% cysts; 21.4% fibrosis; 66.0% subretinal, and 59.2% intraretinal fluid. At 6 months post-baseline: a median of 3 ranibizumab injections (range: 1–6) had been received; the best-corrected visual acuity (BCVA)≥0 letter gain rate was 81.8%; the BCVA ≥15 letter gain rate was 17.0%; BCVA gain was 3.2 letters [mean increase: 3.2±10.0 letters; median: 0.0; p = 0.002]; PED greatest basal diameter (GBD; median: 1470.5 μm) also decreased (median decrease: 114.0 μm; p = 0.019). Baseline central retinal thickness (CRT; median: 312.0 μm) remained unchanged. One patient permanently discontinued ranibizumab due to adverse event occurrence, assessed as not causally related to ranibizumab. There were no ranibizumab-related adverse reactions.

Conclusion

Six-month treatment with ranibizumab in aflibercept inadequate responders led to visual acuity and PED GBD improvements, with no statistically significant CRT change.

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.

Short-Term Results of Switch from Conbercept to Bevacizumab or Ranibizumab in Eyes with Persistent Neovascular Age-Related Macular Degeneration

Purpose

To study the short-term anatomical and functional outcomes in patients with neovascular age-related macular degeneration (nAMD) who were previously treated with conbercept and switched to ranibizumab or bevacizumab due to persistent activity.

Methods

This retrospective single-arm study included nAMD patients who were followed up for at least three months after switching from at least 3 monthly intravitreal conbercept injections to bevacizumab or ranibizumab for persistent choroidal neovascularization (CNV) activity. The demographic data, treatments, best-corrected visual acuity (BCVA), central macular thickness (CMT), and the height of pigmented epithelial detachment (PED) before and after switching were recorded and analyzed.

Results

A total of 64 eyes of 64 patients were included with a mean follow-up of 9.6 ± 3.0 months. The average number of injections of conbercept was 3.6 ± 0.8 (range, 3–5) before switching. 18 eyes were switched to bevacizumab, and the other 46 eyes were switched to ranibizumab. After switching, mean BCVA slowly improved from 0.73 ± 0.48 to 0.64 ± 0.41 (p=0.0132) at one month after the last intravitreal injection of ranibizumab or bevacizumab during the mean follow-up of 4.4 ± 2.0 months. One month after switching, the mean CMT decreased significantly from 294.9 ± 121.8 μm to 230.9 ± 107.0 μm (p < 0.0001) and kept stable during the follow-up. There was a significant reduction of maximum PED height (mPEDH) at the first month after switching (from 384.3 ± 340.3 μm to 287.2 ± 245.2 μm, p=0.0018) and kept stable during the follow-up. The mean PED height at foveal center (cPEDH) showed a regression over time after switching (from 169.3 ± 230.6 μm to 130.5 ± 180.2 μm, p=0.0227) and also kept stable during the follow-up. The proportion of patients with IRF was slightly increased but not statistically significant before switching. After switching, this proportion decreased significantly from 96.9% to 81.3% at one month after the first intravitreal injection of ranibizumab or bevacizumab (p=0.0086). The proportion of patients with SRF did not change significantly before and after switching. The mean decrease of mPEDH and cPEDH at the last follow-up after switching was significantly larger in the IVR subgroup than in the IVB subgroup (p=0.023 and 0.010).

Conclusion

Our results indicate that switching from intravitreal conbercept injections to bevacizumab or ranibizumab can lead to significant improvement of CMT, PED, and IRF and slight improvement of BCVA in a short period of time for persistent nAMD patients.

State-of-the art pharmacotherapy for non-neovascular age-related macular degeneration

INTRODUCTION

Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly in the industrialized world. While effective treatment is available for neovascular AMD, no therapy is successful for the non-neovascular form. Herein, the authors report the current knowledge on non-neovascular AMD pathogenesis and the promising research on treatments.

AREAS COVERED

In the present review, the authors summarize the most recent advances in the treatment of non-neovascular AMD and provide an update on current treatment strategies. Evidence available from preclinical and clinical studies and from a selective literature search is reported.

EXPERT OPINION

When investigating AMD, numerous pathological cascades and alterations of physiological processes have been investigated. It is well-known that AMD is a multifactorial disease, with environmental causes and genetics playing a role. Perturbations in multiple pathogenic pathways have been identified and this led to the development of several molecules directed at specific therapeutic targets. However, despite the huge research effort, the only proven approach so far is oral antioxidant supplementation. We believe that, in addition to successful advancement of promising drugs, further research should be directed at tailoring therapy to specific patient groups, eventually employing a combinational therapy strategy.

How Successful is Switching from Bevacizumab or Ranibizumab to Aflibercept in Age-Related Macular Degeneration? A Systematic Overview

Emerging anti-vascular endothelial growth factor (anti-VEGF) therapies for neovascular age-related macular degeneration (nAMD) have revolutionised medical retina practice and the management and eventual outcome of nAMD. Recent research has focused on evaluating and comparing the efficacy of the two most widely employed anti-VEGF agents, bevacizumab and ranibizumab; however, a subgroup of patients with nAMD demonstrates a suboptimal response to standard therapy. We have therefore conducted a review of pertinent studies published until August 2018 which have documented the clinical efficacy when switching to a different anti-VEGF. Evidence on baseline disease characteristics, injection frequency and disease outcome has been obtained for patients treated with ranibizumab 0.5 mg and/or bevacizumab 1.25 mg and were switched to aflibercept 2 mg. Our review identified 45 studies investigating switching to aflibercept. Our review showed a clear anatomical benefit after the switch in terms of central retinal thickness and pigment epithelium detachment characteristics, whereas the functional outcomes were variable. Remarkable heterogeneity was documented among the relevant studies with regard to several factors including the baseline characteristics of the cohorts, the non-response definition and previous treatment protocols. Larger prospective trials with appropriate control arms are therefore required to elucidate the potential benefit when switching between anti-VEGF agents in refractory nAMD.

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.

Action on neovascular age-related macular degeneration (nAMD): recommendations for management and service provision in the UK hospital eye service

This report by a group of UK retina specialists and health professionals considers best practice recommendations for the management of sight-threatening neovascular age-related macular degeneration (nAMD), based on collective experience and expertise in routine clinical practice. The authors provide an update for ophthalmologists, allied healthcare professionals and commissioners on practice principles for optimal patient care and service provision standards. Refinement of care pathways for nAMD has improved access to intravitreal anti-vascular endothelial growth factor therapy but there are still variations in care and reported outcomes between clinic centres. Innovative organisational models of service provision allow providers to better match capacity with increasing demand. The authors review the recent NICE guideline for diagnosis and management of AMD, considerations for switching therapies and stopping treatment and need for regular monitoring of non-affected fellow eyes in patients with unilateral nAMD. Actions for delivery of high-quality care and to improve long-term patient outcomes are discussed. Local pathways need to detail nAMD target time to treat, maintenance of review intervals to ensure proactive treatment regimens are delivered on time and appropriate discharge for patients deemed low risk or no longer benefiting from treatment. Actual visual acuity outcomes achieved and maintenance of the level of vision when disease stability is achieved are considered good measures for judging the quality of care in the treatment of patients with nAMD. Robust community referral pathways must be in place for suspected reactivation of choroidal neovascularisation and rapid referral for second eye involvement. Practical considerations for intravitreal injection therapy are outlined.

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.

Two-year outcome of treat-and-extend aflibercept after ranibizumab in age-related macular degeneration and polypoidal choroidal vasculopathy patients

Background

The purpose of the study was to evaluate the 2-year outcome and predictive factors of treat-and-extend aflibercept in patients with eyes affected by typical neovascular age-related macula degenelation (t-AMD) or polypoidal choroidal vasculopathy (PCV), who were switched from ranibizumab.

Patients and methods

The patients underwent three monthly aflibercept injections and subsequent administration following the treat-and-extend protocol. Sixty-two eyes of 62 patients were reviewed retrospectively. R statistical software was used for statistical analysis.

Results

Twenty-two eyes were t-AMD and the remaining 40 eyes were PCV. There was no significant difference in the logarithm of the minimal angle of resolution visual acuity (VA) between baseline and 2 years after switching to aflibercept (0.40 vs 0.40; P=0.99). Multivariate analyses suggested that the following factors were significantly correlated with better VA at 2 years after switching to aflibercept: patients with PCV, the absence of intraretinal fluid at baseline, and better VA at baseline.

Conclusion

In conclusion, VA was maintained and there was an anatomical improvement at 2 years in patients with t-AMD and PCV who were switched from ranibizumab to treat-and-extend aflibercept. PCV patients showed more favorable visual outcomes and less injections at 2 years compared to t-AMD patients. Intraretinal fluid and VA at baseline were predictors of VA at 2 years.

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.

Switching between ranibizumab and aflibercept for the treatment of neovascular age-related macular degeneration

The introduction of antivascular endothelial growth factor agents such as ranibizumab and aflibercept has revolutionized the management of neovascular age-related macular degeneration. A number of randomized clinical trials have shown that ranibizumab and aflibercept produce similar efficacy and safety outcomes. Most of the switching studies published to date show that efficacy benefits are uncontrolled, retrospective trials with limitations in terms of their selection, monitoring, numbers, and assessment criteria. Based on the published literature to date, we propose arguments for and against switching antivascular endothelial growth factor agents, provide our own perspective on this topic, and suggest a focus for future research.

The VEGF Treatment of AMD Switch Study (The vTAS Study)

PURPOSE

To evaluate the effect of aflibercept on anatomic and visual outcomes in patients with choroidal neovascularization (CNV) previously treated with intravitreal ranibizumab with persistent fluid on optical coherence tomography (OCT).

DESIGN

Prospective, open-label study.

METHODS

Eighteen patients (19 eyes) with CNV being treated with monthly ranibizumab, with persistent fluid on OCT, were switched to intravitreal aflibercept injections at intervals of up to 8 weeks. The primary outcome was the proportion of patients maintaining vision [<5 letter loss in visual acuity (VA)] at week 48. Secondary outcomes included the change in VA and central macular thickness (CMT) and the frequency of treatment necessary along with the safety of intravitreal aflibercept.

RESULTS

Forty-eight weeks after switching to aflibercept, 16/19 eyes had maintained VA. There was a median increase in vision of 5 letters [interquartile range (IQR): 0, 15; P = 0.06)] and median CMT was reduced from 313 µm (IQR: 214, 334) to 258 µm (IQR: 200, 299; P = 0.02). After stratification by fluid location the reduction in CMT was statistically significant for eyes with intraretinal fluid (IRF) at baseline [median change, -25 µm (IQR: -14, -64); P = 0.01]. Macular volume within 6 mm of the fovea (CMTVol) was significantly reduced in eyes with subretinal fluid (SRF) [-0.20 mm³ (IQR: -1.45, -0.05); P = 0.03].

CONCLUSIONS

In this small cohort of eyes, switching to aflibercept seemed beneficial. The majority maintained or improved vision and eyes with IRF or SRF had significant reductions in macular edema. However, visual improvement was not always indicative of anatomical improvement.

Switch to Aflibercept in the Treatment of Neovascular AMD: Long-Term Results

Purpose

To report the long-term clinical outcomes after switching from intravitreal bevacizumab or ranibizumab to aflibercept therapy in eyes with AMD.

Methods

Retrospective analysis of changes in BCVA, SD-OCT image, and frequency of injections after 1, 2, and 3 years of follow-up.

Results

164 eyes were analyzed, 101 eyes switched from bevacizumab (group 1) and 63 from ranibizumab (group 2). One year after the switch, there was an overall nonsignificant mean decrease of 2 ETDRS letters in BCVA. Three years after, there was an overall mean decrease of 7 ETDRS letters, which was statistically significant. A significant improvement in the mean CRT was found at 1, 2, and 3 years. There was a significant decrease in the mean number of injections per year (7.8 to 6.5, p < 0.005) between the first and third year.

Conclusion

Aflibercept can be useful in the management of refractory neovascular AMD, with a good morphological response. However, in the long-term, BCVA stabilization was not achieved.

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.

The role of Aflibercept in the management of age-related macular degeneration

INTRODUCTION

During the past decade, significant advances have occurred in the management of neovascular age-related macular degeneration (NV-AMD). The advent of anti-vascular endothelial growth factor (anti-VEGF) therapy has shifted the treatment goal of NV-AMD from merely salvaging vision to improving visual acuity and maintaining a good quality of life. Aflibercept (AFL) is a significant addition to the arsenal of anti-VEGF therapies against the NV-AMD. In the index review, pharmacology and efficacy of AFL has been reviewed.

AREAS COVERED

An extensive literature search was performed to identify preclinical and clinical studies performed to illustrate the role of AFL in NV-AMD. Randomized clinical trials evaluating other anti-VEGF agents were also included for comparison. Additionally, studies where AFL was employed to treat anti-VEGF-resistant cases agents have been reviewed.

EXPERT OPINION

AFL is an effective agent in the management of NV-AMD and its efficacy has been found to be comparable to ranibizumab (RBZ). Additionally, AFL is a good alternative agent in patients with NV-AMD resistant to RBZ and bevacizumab (BVZ), and can potentially lessen the treatment burden. As more research is conducted, the role of AFL in varying dosing regimens, as monotherapy and in combination with other agents, will become further defined.

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.