One-Year Effectiveness Study of Intravitreously Administered Conbercept® Monotherapy in Diabetic Macular Degeneration: A Systematic Review and Meta-Analysis

VEGF-targeting drugs for the treatment of retinal neovascularization in diabetic retinopathy

Diabetic retinopathy (DR) is the most common microangiopathic complication of diabetes mellitus, representing a major cause of visual impairment in developed countries. Proliferative DR (PDR) represents the last stage of this extremely complex retinal disease, characterized by the development of neovascularization induced by the abnormal production and release of vascular endothelial growth factor (VEGF). The term VEGF includes different isoforms; VEGF-A represents one of the most important pathogenic factors of DR. Anti-VEGF intravitreal therapies radically changed the outcome of DR, due to combined anti-angiogenic and anti-edematous activities. Nowadays, several anti-VEGF molecules exist, characterized by different pharmacological features and duration. With respect to PDR, although anti-VEGF treatments represented a fundamental step forward in the management of this dramatic complication, a big debate is present in the literature regarding the role of anti-VEGF as substitute of panretinal photocoagulation or if these two approaches may be used in combination. In the present review, we provided an update on VEGF isoforms and their role in DR pathogenesis, on current anti-VEGF molecules and emerging new drugs, and on the current management strategies of PDR. There is an overall agreement regarding the relative advantage provided by anti-VEGF, especially looking at the management of PDR patients requiring vitrectomy, with respect to laser. Based on the current data, laser approaches might be avoided when a perfectly planned anti-VEGF therapeutic strategy can be adopted. Conversely, laser treatment may have a role for those patients unable to guarantee enough compliance to anti-VEGF injections.Key messagesVEGF increased production, stimulated by retinal hypoperfusion and ischaemia, is a major pathogenic factor of neovascular complication onset in diabetic retinopathy and of DR stages progression.Nowadays, several anti-VEGF molecules are available in clinical practice and other molecules are currently under investigation. Each anti-VEGF molecule is characterized by different targets and may interact with multiple biochemical pathways within the eye.All the data agreed in considering anti-VEGF molecules as a first line choice for the management of diabetic retinopathy. Laser treatments may have a role in selected advanced cases and for those patients unable to guarantee enough compliance to intravitreal treatments schemes.

Prognostic Factor Study of Macular Edema Recurrence in Retinal Vein Occlusion after Conbercept Treatment: A Post Hoc Analysis of the FALCON Study

Objective

The study was aimed at exploring the potential predictive factors associated with the recurrence of macular edema (ME) secondary to vein occlusion (RVO) after intravitreal antivascular endothelial growth factor (VEGF) loading treatment in the FALCON study.

Methods

This is a post hoc analysis of 30 patients with central RVO and 30 patients with branch RVO. All patients received a monthly administration of intravitreal conbercept during the 3-month loading phase and pro re nata (PRN) treatment during the 6-month follow-up period. Based on the recurrence of ME at the first follow-up visit, patients were classified into the recurrence group or nonrecurrence group. The primary endpoint was to explore the risk factors for recurrence among baseline characteristics, fluorescein angiography (FA) patterns, and optical coherence tomography (OCT).

Results

In general, 38 patients (64.4%) experienced ME recurrence at the first follow-up visit (3 months), regardless of disease type (p = 0.32). Significant improvements in VA were noted in both the nonrecurrence and recurrence groups (p < 0.001), however, without significant between-group differences (p = 0.1). A significant reduction in CRT in both groups (p < 0.001) was identified, and patients without recurrence showed a greater reduction in CRT compared with those with recurrence (p < 0.001). In addition, logistic regression analyses indicated the corrections of ME recurrence with baseline macular volume and the disruption of the outer limiting membrane at the fovea.

Conclusion

This study suggested that OCT parameters, including baseline macular volume and outer limiting membrane disruption, and reduction in CRT after loading therapy were more predictive of ME recurrence than FA patterns or visual changes following conbercept loading therapy.

Conbercept for Treatment of Neovascular Age-Related Macular Degeneration and Visual Impairment due to Diabetic Macular Edema or Pathologic Myopia Choroidal Neovascularization: A Systematic Review and Meta-Analysis

Background: Conbercept is a new anti-vascular endothelial growth factor (VEGF) drug. Here, we systematically conducted the efficacy, safety, compliance, and pharmacoeconomic evaluation of intravitreal conbercept (IVC) compared with other treatments in patients with neovascular age-related macular degeneration (nAMD), diabetic macular edema (DME), or pathologic myopia choroidal neovascularization (pmCNV). Methods: Databases of PubMed, Embase, Cochrane Library, ClinicalTrials.gov, SinoMed, China National Knowledge Infrastructure, and WanFang Data were systematically searched from the inception to July 27, 2021. Randomized clinical trials and pharmacoeconomic studies comparing IVC with control groups in adults with nAMD, DME, or pmCNV were reviewed and selected. Meta-analyses were performed using the fixed-effects model when pooled data were homogeneous. Heterogeneous data were analyzed using the random-effects model. Primary outcomes included visual improvement rate, mean change in visual acuity or best corrected visual acuity, and pharmacoeconomic outcomes. Additional outcomes were the mean change in fundus examination values, adverse events (AEs), quality-of-life measures, and number of injections. Results: Among 3,591 screened articles, 22 original studies with 1,910 eyes of patients were finally included. For nAMD and DME, IVC was significantly associated with better visual acuity or best corrected visual acuity improvement and fundus quantitative measures than placebo, laser photocoagulation (LP), or intravitreal triamcinolone acetonide (IVT). However, IVC showed non-inferior efficacy to intravitreal ranibizumab (IVR) according to low quality of evidence, and there was lack of trials comparing the priority of IVC to other anti-VEGF regimens. No definitive increased risk of ocular or non-ocular AEs were observed in the study groups. All patients with AEs recovered after symptomatic treatments, and no severe AEs occurred. Patients treated with IVC might have higher quality-of-life scores than those in IVR in nAMD or LP in DME. Additionally, IVC showed cost-utility advantages in nAMD and cost-effectiveness advantages than IVR in pmCNV in China. Conclusion: IVC is well-tolerated and effective for improving vision acuity and quantitative measures in fundus condition in patients with nAMD and DME compared with LP, IVT, and placebo, but gains comparable efficacy to IVR. However, well-designed, large-sample, and long-term evaluation of IVC shall be conducted in additional studies worldwide.