One-year outcomes of intravitreal conbercept combined rescue therapy for polypoidal choroidal vasculopathy in a Chinese population: a real-life clinical data

Recent advances of anti-angiogenic inhibitors targeting VEGF/VEGFR axis

Vascular endothelial growth factors (VEGF), Vascular endothelial growth factor receptors (VEGFR) and their downstream signaling pathways are promising targets in anti-angiogenic therapy. They constitute a crucial system to regulate physiological and pathological angiogenesis. In the last 20 years, many anti-angiogenic drugs have been developed based on VEGF/VEGFR system to treat diverse cancers and retinopathies, and new drugs with improved properties continue to emerge at a fast rate. They consist of different molecular structures and characteristics, which enable them to inhibit the interaction of VEGF/VEGFR, to inhibit the activity of VEGFR tyrosine kinase (TK), or to inhibit VEGFR downstream signaling. In this paper, we reviewed the development of marketed anti-angiogenic drugs involved in the VEGF/VEGFR axis, as well as some important drug candidates in clinical trials. We discuss their mode of action, their clinical benefits, and the current challenges that will need to be addressed by the next-generation of anti-angiogenic drugs. We focus on the molecular structures and characteristics of each drug, including those approved only in China.

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.

The Efficacy of Conbercept in Polypoidal Choroidal Vasculopathy: A Systematic Review

Methods

Thirty studies with 1308 eyes were identified and included in this study. The primary outcome measures were best-corrected visual acuity (BCVA), and secondary outcomes were optical coherence tomography characteristics and polyp regression rates. The pooled results were calculated by the random-effect or fixed-effect model according to the heterogeneity of the data.

Results

Despite a large standard deviation in means (SMD) improvement for BCVA and central retinal thickness (CRT) in the conbercept group, there was no statistically significant difference in the other outcomes compared to ranibizumab and aflibercept. However, there was a greater polyp regression rate in the conbercept group at 12 months.

Conclusions

This systematic review indicates that conbercept may achieve similar BCVA and CRT improvements as ranibizumab and aflibercept, with a superior rate of polyp regression at 12 months.