Short-term efficacy of intravitreal conbercept in treatment-naive patients with polypoidal choroidal vasculopathy

Effect of Conbercept on Corneal Neovascularization in a Rabbit Model

OBJECTIVE

To study the efficacy of Conbercept for the treatment of corneal neovascularization (NV) in a rabbit model.

METHODS

NV was induced by placing sutures. Eight rabbits were used as a control. The other 136 rabbits were randomly divided into two equal groups, and 68 rabbits in each group were divided into four subgroups and given different treatments. Time-course photographs, histological examination, and enzyme-linked immunoassay ELISA analysis for vascular endothelial growth factor were performed at weeks 1, 2, and 3 after injection placement.

RESULTS

At weeks 1, 2, and 3 after injection placement, there was less expression of corneal NV and VEGF in the conbercept-treated groups than in the saline-treated control groups and less corneal NV and VEGF were expressed in the early treatment group than in the late treatment group. At weeks 2 and 3 after injection, there were fewer corneal NV (length and area) in the early intrastromal injection group with conbercept than in the early subconjunctival injection group with conbercept and a smaller diameter of corneal NV than in the late intrastromal injection group treated with conbercept. Histological examination showed a smaller diameter of corneal NV in all eyes in conbercept-treated groups 1 w after injection than before injection. Treatment with subconjunctival injection with conbercept led to a larger diameter at weeks 2 and 3 than at week 1.

CONCLUSIONS

Subconjunctival and intrastromal administrations of conbercept effectively inhibit corneal NV in rabbits, and the latter has the better effect. The effect is the best in the group with cornea intrastromal injection of conbercept 1 w after suture. Early administration of conbercept may successfully inhibit corneal NV in an animal model.

The comparison of two different strategies of intravitreal conbercept for polypoidal choroidal vasculopathy in Chinese patients results from a 48-week randomized phase 4 study: STAR study

PURPOSE

To compare a treat-and-extend (TAE) strategy with a fixed dosing regimen of intravitreal conbercept (IVC) for the management of treatment-naïve polypoidal choroidal vasculopathy (PCV) patients.

METHODS

249 patients with treatment-naïve PCV were randomized 1:1 to fixed dosing regimen with injections every 12 weeks (3 + Q12W) group or treat-and-extend regimen(3 + TAE) group. Patients received 3 monthly intravitreal injections of 0.5 mg conbercept as loading dose in both groups. The 3 + Q12W patients were monitored monthly and received mandated injections every 12 weeks; the 3 + TAE patients were monitored and treated monthly until the resolution of exudative disease activity; the interval between visits was then individualized according to study protocol. Visual and anatomical outcomes were compared between the two groups.

RESULTS

At 48 weeks, there was no significant difference between the 3 + Q12W group and 3 + TAE group in mean BCVA improvement (p = 0.421), mean changes in central retinal thickness (CRT) (p = 0.818), maximum retinal thickness (MRT) (p = 0.448), pigment epithelial detachment (PED) height (p = 0.221), PED volume (p = 0.076), branching vascular network (BVN) area (p = 0.615), polypoidal lesion number (p = 0.701), polypoidal lesion area (p = 0.424), rates of patients who avoided vision loss of ≥15 ETDRS letters (p = 0.397) or complete polypoidal lesion regression rate (43.8% vs. 41.8%, p = 0.814). The 3 + Q12W group had more decreased retinal haemorrhage area (p = 0.014) and fewer mean numbers of injections comparing with 3 + TAE group (6.6 vs. 9.4, p < 0.001). Mean maximum extension interval between injections after loading injections was 9.6 ± 2.0 weeks for 3 + TAE group, with 27.8% of patients achieving an extension interval of 12 weeks and 61.1% patients 8 weeks or more.

CONCLUSIONS

Both 3 + Q12W and 3 + TAE regimens of IVC could result in improvement in visual and anatomical outcomes in PCV patients.

Intravitreal Conbercept for Idiopathic Choroidal Neovascularization in Nursing Women

Purpose: To report the clinical course and vascular endothelial growth factor (VEGF) levels in breast milk among three nursing women diagnosed with idiopathic choroidal neovascularization (CNV) before and after intravitreal injection of conbercept. Methods: This was an observational case series. The main outcomes and measures included best-corrected visual acuity (BCVA), anatomical features using optical coherence tomography, and breast milk concentrations of VEGF before and after the intravitreal injection of conbercept. Results: BCVA was increased, and no ocular or systemic safety problems were observed in any of the three patients during the follow-up period. An enzyme-linked immunosorbent assay was used to measure VEGF concentrations in the breast milk samples. Samples were collected 1 day before and 1, 7, and 30 days after the first intravitreal injection of conbercept. After conbercept injection, VEGF levels in breast milk were slightly decreased and did not change significantly in the following week; levels recovered fully by 30 days post-treatment. Conclusions: Intravitreal injection of conbercept shows favorable effectiveness and safety in the treatment of idiopathic CNV in nursing women and does not result in a significant reduction in VEGF in human breast milk.

Elevated Levels of Endoglin, Endostatin, FGF-α, HGF, and Thrombospondin-2 in Aqueous Humor of nAMD Patients

Purpose: to explore the aqueous cytokine profiles in nAMD patients before and after conbercept therapy.Methods: aqueous levels of 17 cytokines were detected in 20 treatment-naïve nAMD eyes and 20 age- and sex-matched age-related cataract (ARC) eyes. All of the nAMD patients received three intravitreal injections of conbercept. The central macular thickness (CMT) and maximum retinal thickness-3 mm (MRT-3 mm) were measured by SD-OCT. Fundus fluorescein angiography (FA) was used to measure the greatest linear diameter (GLD).Results: Aqueous endoglin, endostatin, FGF-α, HGF, and thrombospondin-2 levels were significantly higher in the nAMD group than those in the ARC group, whether before or after two conbercept injections. In the nAMD group, baseline thrombospondin-2 was positively correlated with GLD. Baseline FGF-α, thrombospondin-2, and VEGF-A were positively correlated with MRT-3 mm. After two conbercept injections, endostatin levels were positively correlated with VEGF-A.Conclusions: Endoglin, endostatin, FGF-α, HGF, and thrombospondin-2 may participate in the pathogenesis of nAMD.

Comparison of the Efficacy of Three Loading Doses of Intravitreal Injection of Conbercept with Injection Combined with PDT for the Treatment of PCV

Purpose

To compare the efficacy between initial 3-monthly intravitreal conbercept monotherapy and combination intravitreal conbercept with photodynamic therapy (PDT) for polypoidal choroidal vasculopathy (PCV).

Methods

This is a retrospective, comparative study which involved 65 PCV eyes of 65 patients. According to the therapeutic regimen, the PCV patients were divided into two groups: 32 eyes with naive PCV received a PDT after the first intravitreal injection of conbercept (IVC) followed by pro re nata (prn) retreatment (combination group), and 33 eyes with naïve PCV received 3-monthly IVC monotherapy followed by prn regimen (IVC monotherapy group). All patients completed at least 6 months of monthly follow-up.

Results

At month 6, best-corrected visual acuity (BCVA) improved significantly (P < 0.05) in both groups compared with that at baseline; the mean changes of BCVA between the IVC monotherapy group and combination group have no significant difference (−0.22 ± 0.22 vs. −0.17 ± 0.22 LogMAR, P = 0.38). The central retinal thickness (CRT) decreased significantly in the two groups (P < 0.05), with no difference between the two groups (P = 0.24). The complete regression rate of polyps was 58.6% (17 out of 29 eyes) in the IVC monotherapy group and 80.65% (25 out of 31 eyes) in the combination group, respectively (P = 0.09, χ-squared test). The combination group required significantly fewer injections than the IVC monotherapy group (3.09 ± 0.89 vs. 3.67 ± 0.74, P = 0.006).

Conclusion

Conbercept monotherapy significantly improved visual acuity and effectively regressed polyps during 6-month follow-up time in the treatment of PCV.

One-year results of intravitreal conbercept in treatment-naïve subjects with polypoidal choroidal vasculopathy

PURPOSE

To evaluate the functional and structural outcomes of intravitreal conbercept monotherapy using a "3 + pro re nata (PRN)" regimen in treatment-naïve subjects with polypoidal choroidal vasculopathy (PCV) up to 12 months.

METHODS

Thirty subjects (30 eyes) with PCV participated in this interventional, retrospective study. All subjects received intravitreal injections of 0.5 mg (0.05 ml) conbercept using a "3 + PRN" regimen for 12 months. The changes in best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) parameters, polyp lesion area, and regression rate were evaluated at baseline, month 3, and month 12.

RESULTS

At the study end-point, BCVA improved significantly from 52.80 ± 17.17 ETDRS letters at baseline to 62.20 ± 18.96 letters (P < 0.001), with a mean gain of 9.40 ± 14.97 letters. The central retinal thickness (CRT) significantly reduced from 454.93 ± 147.31 μm at baseline to 308.73 ± 106.80 μm (P < 0.001) at end-point, and the total macular volume (TMV) decreased from 9.51 ± 1.04 mm³ at baseline to 8.32 ± 0.84 mm3 at end-point (P < 0.001). The mean volume of pigment epithelial detachment (PED) decreased from 0.73 ± 0.97 mm³ at baseline to 0.48 ± 0.71 mm³ (P < 0.05) at month 3. At month 12, the mean volume of PED was 0.57 ± 0.80 mm³ (P > 0.05 compared to baseline). After the 3-monthly loading injections, 6 eyes (20.0%) showed complete polyp regression, whereas a total of 19 eyes (63.5%) showed complete regression at month 12. The average injections given per subject were 7.70 ± 1.81.

CONCLUSION

Intravitreal conbercept using the "3 + PRN" regimen was effective in the treatment of PCV.

Updates on the Management of Ocular Vasculopathies with VEGF Inhibitor Conbercept

Purpose: To provide a detailed review on the therapeutic efficacy of conbercept for the management of ocular vasculopathies. Methods: A comprehensive literature search of various electronic databases was performed. Results: Ocular vasculopathy is one of the major causes of visual impairment and blindness which includes a range of disorders. Vascular endothelial growth factor (VEGF) regulates angiogenesis, enhances vascular permeability, and drives the formation of neovascularization. Anti-VEGF therapy has been shown to prevent vision loss or potentially improve vision in patients with exudative or neovascular retinal disease. The most recent anti-VEGF drug in China is conbercept. In the USA and Europe, bevacizumab is the most recently approved anti-VEGF agent. Conclusions: Conbercept serves as another anti-VEGF option for patients with neovascular AMD and other retinal vascular disorders. There have not been many clinical trials that study conbercept as compared with other currently available anti-VEGF drugs. There is a need for large-scale, well-designed, randomized clinical trials to ensure its long-term safety and efficacy and to determine if it has any advantages over other anti-VEGF agents.