The role of aflibercept in the management of diabetic macular edema

Management of treatment-naïve diabetic macular edema patients: Review of real-world clinical data

The high prevalence of Diabetic macular edema (DME) is a real global health problem. Its complex pathophysiology involves different pathways. Over the last decade, the introduction of intravitreal treatments has dramatically changed the management and prognosis of DME. Among the different treatment options, inhibitors of vascular endothelial growth factor (anti-VEGF) and intravitreal steroids implants represent the first-line therapy of DME. We conducted a review of electronic databases to compile the available evidence about the clinical management of DME in a clinical setting, with a special focus on treatment-naïve patients. Anti-VEGF therapies represent a valuable option for treating DME patients. However, many patients do not respond properly to this treatment and, due to its administration regimen, many patients receive suboptimal treatment in real life. Current evidence demonstrated that in patients with DME, DEX-i improved significantly both anatomic and visual outcomes. Besides eyes with insufficient anti-VEGF respond or recalcitrant DME cases, DEX-i can be effectively and safely used in treatment-naïve DME patients as first line therapy. DEX-i may be considered first line therapy in different clinical scenarios, such as DME eyes with a greater inflammatory component, patients with cardiovascular events, vitrectomized eyes, or those requiring cataract surgery. In conclusion, there are still many points for improvement pending in the clinical management of the patient with DME. Since DME treatment must follow a patient-tailored approach, selecting the best therapeutic approach for each patient requires a good understanding of the pathophysiology of DME.

Intravitreal aflibercept partially reverses severe non-proliferative diabetic retinopathy in treatment-naïve patients

Objective

To evaluate whether diabetic retinopathy can be reversed after aflibercept, based on improvements in diabetic macular edema, hard exudates (HEs) of the posterior pole, and retinal microaneurysms (MAs).

Methods

This was a single-center retrospective study of 30 patients (34 eyes) with severe non-proliferative diabetic retinopathy (NPDR) who were treated between August and October 2018. Best-corrected visual acuity (BCVA), central foveal thickness (CFT), area of HEs, and number of MAs were compared before and after treatment.

Results

The mean patient age was 61.4 ± 7.1 years; 14 patients (46.7%) were men. The mean number of injections per patient was 3.5 ± 0.5. The time between the last injection and the last follow-up was 82 days (range, 78–110 days). Six months after the first intravitreal injection, significant improvement was observed in BCVA (from 0.70 ± 0.18 to 0.42 ± 0.19 logMAR), CFT (from 377.17 ± 60.41 to 261.21 ± 31.50 µm), and number of MAs (from 182.2 ± 77.4 to 101.5 ± 59.6). Observations over 6 months after the first intravitreal injection showed a statistically significant reduction in the area of HEs (P = 0.007). No adverse events occurred during the treatment period.

Conclusion

Diabetic retinopathy might be partially reversed by aflibercept treatment, as indicated by BCVA, CFT, number of MAs, and area of HEs.

Choroidal Thickness After Dexamethasone Implant or Aflibercept in Patients with Diabetic Macular Edema Persistent to Ranibizumab

Purpose: This study aims to compare subfoveal choroidal thicknesses (SFCTs) after intravitreal dexamethasone (IVD) or intravitreal aflibercept (IVA) treatment in patients with persistent diabetic macular edema (DME) unresponsive to intravitreal ranibizumab (IVR). Methods: The study consisted of patients with DME unresponsive to IVR treatment in which 37 were administered 1 dose IVD (group A) and 34 patients who were administered 3 doses of IVA (group B), as well as 35 healthy individuals (group C). Detailed ophthalmological examination and optical coherence tomography parameters of group A and group B, including central retinal thickness and SFCT, were retrospectively evaluated before and after treatment. Results from preinjection, and 1, 2, and 3 months after injection were analyzed. Results of group A and group B were compared within themselves and also compared with group C. Results: SFCT measurements were compared within group A and group B (1 = preinjection; 2 = 1 month postinjection; 3 = 2 months postinjection; 4 = 3 months postinjection). There was significant thinning in SFCT between 1-2, 1-3, 1-4, 2-3, 2-4, and 3-4 time intervals within both group A and group B (both P < 0.001). Comparison of SFCT measurements showed preinjection, 1-, and 2-month values of group A were significantly thicker than those of group C (P < 0.001), whereas there was no significant difference between 3-month values (P = 0.09). Preinjection, 1-, and 2-month values of group B were significantly thicker than those of group C (P < 0.001), whereas there was no significant difference between 3-month values (P = 0.06). Conclusions: Three month follow-up showed thinning in SFCT measurements in patients with persistent DME unresponsive to IVR who were applied IVD or IVA treatment.

Current concepts of pharmacotherapy of diabetic macular edema

Introduction: Diabetic macular edema (DME) is a sight threatening disease and a major cause for blindness for people in working age. The pathogenesis is multifactorial and complex. The pharmacotherapy of DME addresses both the inhibition of vascular endothelial growth factor (VEGF) by the intravitreal injection of VEGF inhibitors and inflammatory processes by the intravitreal application of steroids. Several trials have been published reporting on the efficacy and safety of these treatments.Areas covered: This review discusses original research articles including basic science and clinical studies as well as review articles focusing on the role of inflammation and VEGF expression in DME. It discusses newly published clinical trials on intravitreal pharmacotherapy for DME. The literature was searched using Medline/PubMed and was selected given its relevance for the topic to be discussed.Expert opinion: Our knowledge regarding the pathophysiology of diabetic macular edema has significantly increased. Some of these insights have been successfully transferred into current treatment strategies already including VEGF suppression or anti-inflammatory treatments using steroids. The identification of additional pathophysiological aspects and their relevance as potential treatment targets will be a future challenge in the treatment of DME. A better knowledge on the complex pathophysiology will also help to establish combination strategies.

Evaluation of ranibizumab and aflibercept for the treatment of diabetic macular edema in daily clinical practice

PURPOSE

To evaluate the efficacy and safety of ranibizumab and aflibercept in the treatment of diabetic macular edema in a real world study, and to compare the two treatments with each other.

METHODS

Retrospective observational study of 213 eyes from 141 patients with diabetic macular edema was completed between June 2014 and June 2016. 122 were treated with ranibizumab intravitreal injection and 91 with aflibercept intravitreal injection, with a loading phase of 3 injections and a Pro Re Nata protocol. The drug was selected by the physician and fluorescein angiography was performed by physician`s criteria. Re-treatment was performed when a decline in BCVA, an increase of central macular thickness or an increase or persistence of intraretinal fluid in OCT was observed. The primary outcome was the mean change in best corrected visual acuity at 1 year, while central macular thickness, central macular volume, the number of injections and visits were evaluated as secondary outcomes. The correlation between BCVA at 4th month visit and BCVA at 12th month visit was also evaluated.

RESULTS

The mean baseline best corrected visual acuity for the eyes treated with ranibizumab was 0.55 (+/- 0.35) logMAR, and with aflibercept it was 0.48 (+/- 0.29) (P = 0.109). Best corrected visual acuity improved in both groups, and at the end of the follow-up was 0.40 (+/- 0.35) in the ranibizumab group and 0.40 (+/- 0.29) in the aflibercept group (P = 0.864). Best corrected visual acuity at 4th month visit is correlated at a high value (R = 0.789) with the one at the end of the study. No differences were found in central macular thickness, central macular volume and glycosylated hemoglobin when adjusting with baseline values. The overall number of injections was 5.77 (+/- 2.01), being 5.56 (+/- 2.0) in the ranibizumab group and 6.07 (+/- 1.99) in the aflibercept group (P = 0.069). The main outcome determining final best corrected visual acuity was the baseline best corrected visual acuity (P<0.001).

CONCLUSION

There are no differences in efficacy between ranibizumab and aflibercept in diabetic macular edema treatment in this real world study.

EFFECTS OF INTRAVITREAL RANIBIZUMAB AND BEVACIZUMAB ON THE RETINAL VESSEL SIZE IN DIABETIC MACULAR EDEMA

PURPOSE

The goal of this study was to assess the effects of a single injection of intravitreal ranibizumab (RAN) or bevacizumab (BEV) on the retinal vessel size in eyes with diabetic macular edema.

MATERIALS AND METHODS

In total, 32 patients were enrolled in the RAN group, and 30 patients were included in BEV group. Each of these groups was also subdivided into two others groups: a study group and a control group. The study groups were composed of the injected eyes, whereas the noninjected fellow eyes served as the control groups. The patients underwent complete ophthalmic examinations, including optical coherence tomography and fundus fluorescein angiography, and the primary outcome measures included the central retinal artery equivalent, central retinal vein equivalent, and artery-to-vein ratio.

RESULTS

In the RAN study group (n = 32), the preinjection mean central retinal artery equivalent (175.42 μm) decreased to 169.01 μm after 1 week, and to 167.47 μm after 1 month (P < 0.001), whereas the baseline central retinal vein equivalent (235.29 μm) decreased initially to 219.90 μm after 1 week, and to 218.36 μm after 1 month (P < 0.001). In the BEV study group (n = 30), the preinjection central retinal artery equivalent (150.21 μm) decreased to 146.25 μm after 1 week, and to 145.89 μm after 1 month (P < 0.001); whereas the baseline central retinal vein equivalent (211.87 μm) decreased initially to 204.59 μm after 1 week and was 205.24 μm after 1 month (P < 0.001). The preinjection artery-to-vein ratio values changed significantly (P = 0.001) after 1 week and after 1 month in the RAN group, but no significant alteration in the artery-to-vein ratio was observed in the BEV group (P = 0.433). In both the RAN (n = 32) and BEV (n = 30) control groups, none of the 3 parameters changed throughout the study period, when compared with the baseline.

CONCLUSION

The results of this study showed that both RAN and BEV injections significantly constricted the retinal blood vessel diameters.

Aflibercept for clinically significant diabetic macular edema: 12-month results in daily clinical practice

Purpose

To assess the effectiveness and safety of intravitreal aflibercept in clinically significant diabetic macular edema (DME) in daily clinical practice.

Methods

Prospective, open-label, single-center study. Anti-vascular endothelial growth factor naïve patients with clinically significant DME received intravitreal injections of aflibercept 2 mg, five monthly doses followed by a fixed schedule every 2 months for 12 months. The mean change in best-corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS] letters) was the primary outcome.

Results

The mean BCVA improved significantly as compared with baseline at 12 months of treatment (47.3 [14.2] vs 62.2 [13.9] ETDRS letters, P<0.001). Significant improvement in BCVA was already observed at visit 2 after the loading doses of aflibercept. At 12 months, gains in ETDRS letters were documented in all eyes (100%), with gains ≥10 letters in 89.6%, ≥15 letters in 65.5%, and ≥20 letters in 6.9% (n=2). A significant reduction in central macular thickness from a mean of 460.5 (11.8) μm at baseline to 229.0 (43.8) μm at 12 months (P<0.001) was observed. Significant reductions of central macular thickness were already observed after the loading doses and continued lowering throughout the study period. No adverse events occurred.

Conclusion

Aflibercept as a first-line therapy was effective and well tolerated for treating clinically significant DME in naïve patients in daily practice. Successful results in terms of improvement of visual and reduction in central macular thickness contribute to provide evidence for the positioning of aflibercept as a first-line indication of newly diagnosed clinically significant DME.

Retinal and choroidal angiogenesis: a review of new targets

Retinal and choroidal neovascularization are a major cause of significant visual impairment, worldwide. Understanding the various factors involved in the accompanying physiopathology is vital for development of novel treatments, and most important, for preserving patient vision. The intraocular use of anti-vascular endothelial growth factor therapeutics has improved management of the retinal and choroidal neovascularization but some patients do not respond, suggesting other vascular mediators may also contribute to ocular angiogenesis. Several recent studies examined possible new targets for future anti-angiogenic therapies. Potential targets of retinal and choroidal neovascularization therapy include members of the platelet-derived growth factor family, vascular endothelial growth factor sub-family, epidermal growth factor family, fibroblast growth factor family, transforming growth factor-β superfamily (TGF-β1, activins, follistatin and bone morphogenetic proteins), angiopoietin-like family, galectins family, integrin superfamily, as well as pigment epithelium derived factor, hepatocyte growth factor, angiopoietins, endothelins, hypoxia-inducible factors, insulin-like growth factors, cytokines, matrix metalloproteinases and their inhibitors and glycosylation proteins. This review highlights current antiangiogenic therapies under development, and discusses future retinal and choroidal pro- and anti-angiogenic targets as wells as the importance of developing of new drugs.