Efficacy of Initial vs. Delayed Photodynamic Therapy in Combination With Conbercept for Polypoidal Choroidal Vasculopathy

Abstract

Purpose: To compare the efficacy of initial vs. delayed photodynamic therapy (PDT) in combination with intravitreal injection of conbercept (IVC) for polypoidal choroidal vasculopathy (PCV).

Design: Multicenter, randomized, non-inferiority clinical trial.

Subjects: Naïve PCV patients.

Methods: Patients were randomized 1:1 into two groups: initial PDT with IVC and delayed PDT with IVC. At baseline, patients in the initial combination group were treated with PDT and IVC within 1 week, while patients in the delayed combination group were treated with IVC alone. PDT and IVC was given PRN during the follow-up in each group.

Main outcome measures: Non-inferiority of delayed PDT with IVC to initial PDT with IVC for mean change in best-corrected visual acuity from baseline to month 12 (95% CI of the difference entirely above -5 letters).

Results: Eighty-six patients were enrolled, with 43 in each group. At month 12, the change of BCVA in initial combination group was equivalent to that in the delayed combination group, with gains of 6.42 ± 1.89 and 7.49 ± 2.14 (mean ± standard error) letters, respectively [delayed group minus initial group: 1.07 letters; 95% confidence interval (CI): -4.62 to 6.76; P non-inferiority = 0.0198]. The rates of complete polyp regression were 66.67 and 45.83% in the initial and delayed combination groups, respectively. The difference was not statistically significant (P = 0.386). The mean reductions of CRT were 204.77 ± 28.79 and 84.14 ± 30.62 μm in each group respectively. The difference was statistically significant (P = 0.005). In addition, the mean injection numbers were 3.47 ± 2.39 and 4.91 ± 2.65 in each group respectively. The differences were statistically significant (P = 0.010).

Conclusions: There was effective in both groups in patients with PCV. The initial combination group showed a more efficient decrease in CRT and polyp regression, along with fewer injections. However, the initial combination group was non-inferior compared with the delayed combination group in terms of the improvement of BCVA.

Trial registration: https://ClinicalTrials.gov, Identifier: NCT02821520.

Keywords: conbercept; efficacy; non-inferiority; photodynamic therapy; polypoidal choroidal vasculopathy.

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2022 Sun, Gong, Yang, Huang, Yu, Pei, Lin, Zhou, Li, Li, Zhang and Liu.

Figures

Figure 1

Consolidated Standards of Reporting Trials (CONSORT) diagram showing progress of patients through the study. PDT, photodynamic therapy; IVC, intravitreal injection of conbercept.

Figure 2

(A) Mean change of BCVA from baseline to month 12. (B) Differences in BCVA change from baseline to month 12 between the two groups. The black vertical lines indicated the mean difference between the two groups, and the gray bar was the 95.0% CI. CI within −5 and +5 letters (dashed vertical lines) indicated that the two groups were equivalent. A lower limit of the 95.0% CI with a value above −5 showed that delayed PDT combined with IVC was non-inferior compared with initial PDT combined with IVC. BCVA, best-corrected visual acuity; CI, confidence interval; PDT, photodynamic therapy; IVC, intravitreal injection of conbercept.

Figure 3

(A) Waterfall plots of BCVA changes from baseline to month 12 for individual patients. These plots showed that all the BCVA scores improved except 10 patients in initial PDT with IVC and 6 patients in delayed PDT with IVC. (B) Waterfall plots of CRT changes from baseline to month 12 for individual patients. These plots showed that all the CRT thicknesses decreased from baseline except two patients in initial PDT with IVC and 11 patients in delayed PDT with IVC. BCVA, best-corrected visual acuity; CRT, central retinal thickness; PDT, photodynamic therapy; IVC, intravitreal injection of conbercept.

Figure 4

Mean change of CRT from baseline to month 12. CRT, central retinal thickness.