Conbercept vs Panretinal Photocoagulation for the Management of Proliferative Diabetic Retinopathy

Study Overview
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Brief Summary
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Panretinal photocoagulation (PRP) has been the standard treatment for Proliferative diabetic retinopathy (PDR) since the Diabetic Retinopathy Study demonstrated its benefit nearly 40 years ago,but PRP has inevitable adverse effects on visual function. Intravitreal injection of vascular endothelial growth factor(VEGF) can induce short-term regression of retinal neovascularization(NV). The purpose is to assess and compare the efficacy and safety between intravitreal injection of conbercept and PRP.

Detailed Description
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Proliferative diabetic retinopathy (PDR) is a leading cause of vision loss in patients with diabetes mellitus,which of the initial manifestation of PDR is retinal neovascularization at the disc or elsewhere.Panretinal photocoagulation (PRP) has been the standard treatment for PDR since the Diabetic Retinopathy Study demonstrated its benefit nearly 40 years ago,but PRP has inevitable adverse effects on visual function including peripheral visual field defects, night vision loss, loss of contrast sensitivity.Recent evidences have indicated that anti-vascular endothelial growth factor(VEGF) treatment can reduce the severity and delay the progression of DR.However,the impact of this treatment on visual function and the effect of anti-VEGF agents on retinal neovascularization compared with PRP remain unclear. It is possible that a long-acting anti-VEGF agent such as conbercept. So we design the study with is a prospective randomized controlled trial about Intravitreal injection of conbercept versus PRP on PDR.Primary outcome is the change in BCVA from screening to 12 months in the study eye measured in the ETDRS letter score at 4 m

Official Title
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Conbercept vs Panretinal Photocoagulation for the Management of Proliferative Diabetic Retinopathy

Conditions
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Proliferative Diabetic Retinopathy

Intervention / Treatment
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* Drug: intravitreal injection of conbercept
* Device: PRP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants of either sex aged 18 years or over. Diagnosis of diabetes mellitus (type 1 or 2). Best-corrected visual acuity (BCVA) in the study eye better than or equal to 30 Early Treatment Diabetic Retinopathy Study (ETDRS) letters PDR with no evidence of previous PRP. Media clarity, pupillary dilation and participant cooperation sufficient for adequate fundus photographs. Exclusion Criteria: a glycated haemoglobin (HbA1c) level of more than 10%; Blood pressure > 180/100 mmHg Myocardial infarction, other acute cardiac event requiring hospitalization, stroke, transient ischemic attack, or treatment for acute congestive heart failure within 6 months dialysis or renal transplant Systemic anti-VEGF or pro-VEGF treatment within 6 months prior to randomization For women of child-bearing potential: pregnant or lactating or intending to become pregnant within the next 3 years Traction retinal detachment involving the macula Exam evidence of neovascularization of the angle History of major ocular surgery or anticipated within the next 6 months following randomization

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: IVC group<br>intravitreal injection of conbercept (IVC) group：all study eyes randomised to receive conbercept will receive an intravitreal injection of conbercept 2 mg/ 0.05 mL at baseline and at 1 and 2 moths. Further treatment since months 3 is determined by the degree of regression of neovascularization (NV) of disc and elsewhere on clinical examination | Drug: intravitreal injection of conbercept<br>* conbercept is an anti-VEGF agent and is approved by the Food and Drug Administration for wet age-related macular degeneration<br>* Other names: KH-902 (Chengdu Kanghong Biotech Co., Ltd., Sichuan, China);|
| Active Comparator: PRP group<br>panretinal photocoagulation (PRP) group:all study eyes randomised to receive PRP will receive an fill-in PRP in 1-2 two weekly sessions as per routine clinical practice with emphasis on targeting retinal nonperfusion areas | Device: PRP<br>* panretinal photocoagulation (PPR) is the standard treatment for proliferative diabetic retinopathy (PDR) and is applied to the peripheral retinal tissue to ablate areas of the peripheral retina and thereby reduce retinal oxygen consumption<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary outcome is mean visual acuity change(BCVA) | Primary outcome is the change in BCVA from screening to 12 moths in the study eye measured in the ETDRS letter score at 4 m | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual acuity outcomes in terms of visual gain or loss | visual gain refers to the proportion of visual improvement ≥ 15 letters at 6-month follow-up, visual loss refers to the proportion of visual reduction ≤ 15 letters at 6-month and 12-month follow-up | 6 months and 12 months | 
| the regression patterns of new vessels | the complete regression proportion of new retinal vessels is evaluated by the fundus photography and fundus fluorescein angiography at 6 months and 12 months | 6 months and 12 months | 
| proportion of patients developing macular oedema, vitreous haemorrhage and vitrectomy | proportion of patients developing macular oedema, vitreous haemorrhage and vitrectomy at months | 12 months | 
| change of visual field | change of visual field will be evaluated by the perimeter | 12 months | 
| change of retinal function | change of retinal function measured by electroretinography(ERG) | 12 months | 
| change of macular capillary density | change of macular capillary density measured by Optical coherence tomography angiography | 12 months | 
| change of central retinal thickness | change of central retinal thickness measured by Optical coherence tomography | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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conbercept, anti-VEGF agent, panretinal photocoagulation