Intravitreal conbercept for diabetic macular oedema: 2-year results from a randomised controlled trial and open-label extension study

Abstract

Background: To demonstrate the efficacy and safety of intravitreal injections of conbercept versus laser photocoagulation in the treatment of diabetic macular oedema (DME).

Methods: A 12-month multicentre, randomised, double-masked, double-sham, parallel controlled, phase III trial (Sailing Study), followed by a 12-month open-label extension study. Patients with centre-involved DME were randomly assigned to receive either laser photocoagulation followed by pro re nata (PRN) sham intravitreal injections (laser/sham) or sham laser photocoagulation followed by PRN 0.5 mg conbercept intravitreal injections (sham/conbercept). Patients who entered the extension study received PRN conbercept treatment. The primary endpoint was the changes in best-corrected visual acuity (BCVA) from baseline.

Results: A total of 248 eyes were included in the full analysis set and 157 eyes continued in the extension study. Significant improvement in mean change in BCVA from baseline to month 12 was observed in the sham/conbercept group (8.2±9.5 letters), whereas no improvement was observed in the laser/sham group (0.3±12.0 letters). Patients in the laser/sham group showed a marked improvement in BCVA after the switch to conbercept in the extension study, and there was no difference in BCVA between the two groups at the end of the extension study.

Conclusion: The use of a conbercept PRN intravitreal injection regimen improved the BCVA of patients with DME, and its efficacy was better than that of laser photocoagulations, and the same efficacy was observed when the eyes treated with laser alone were switched to conbercept.

Trial registration number: NCT02194634.

Keywords: clinical trial; macula; retina; treatment lasers.

Figure 1

Study flowchart.

Figure 2

Mean changes in BCVA for laser and conbercept study groups in the Sailing Study. (A) One-year results compared with baseline. (B) Two-year results compared with baseline for the subset of eyes that continued in the extension study. Error bars denote SD. BCVA, best-corrected visual acuity.

Figure 3

Mean changes of secondary endpoints for laser and conbercept study groups in the Sailing Study. (A) One-year results of mean CRT changes compared with baseline. (B) Extension study results of mean CRT changes from 12 to 24 months. (C) Mean changes in TMV compared with baseline (1-year results). (D) Mean changes in TMV from 12 to 24 months (extension study results). (E) Mean change in NEI VFQ-25 total score from baseline to month 12 of the Sailing Study. Error bars denote SD. CRT, central retinal thickness; NEI VEQ-25, 25-Item National Eye Institute Visual Function Questionnaire; TMV, total macular volume.