Conbercept improves visual acuity in age-related macular degeneration
Administering conbercept at a dose of 0.5 mg once monthly for the first 3 months then once quarterly until month 12 appears to be effective in the treatment of age-related macular degeneration (AMD), with significant improvements in visual acuity observed at month 3 and maintained through 1 year, according to the results of the phase III PHOENIX trial.
“Because other anti-VEGF [vascular endothelial growth factor] agents cannot support [the said] dosing regimen, treatment using conbercept has the potential to be a more patient-friendly treatment than are existing treatments,” the authors said.
PHOENIX randomized 124 patients (aged ≥50 years) with active, primary or recurrent subfoveal or juxtafoveal choroidal neovascularization (CNV) secondary to AMD to receive either conbercept (n=81) or sham injection (n=43). The dosing regimen used was as follows: three sequential monthly injections, with additional injections given once every 3 months until month 12.
Efficacy and safety were assessed in 114 patients who completed the 12-month study. At baseline, lesion size was <30 mm2, and best-corrected visual acuity (BCVA) letter scores ranged between 73 (20/40 Snellen equivalent) and 19 (20/400 Snellen equivalent) letters. The primary efficacy endpoint of mean change in BCVA at month 3 was significantly greater with conbercept vs sham (9.20 vs 2.02 letters; p<0.001). [Am J Ophthalmol 2018;doi:10.1016/j.ajo.2018.08.026]
Improvements in BCVA persisted at 12 months, although the changes were not significantly different between the two groups (9.98 vs 8.81 letters; p=0.64).
The study drug was generally well-tolerated. Adverse events (AE), ocular or nonocular, occurred in 40 patients (49.4 percent) in the conbercept group and in 16 (37.2 percent) in the sham group. The most common AEs were injection site haemorrhage and increased intraocular pressure.
There were no reports of cataract, vitreous haemorrhage or serious ocular inflammation (sterile or infectious endophthalmitis) in the study eyes of the conbercept group, nor there were accounts of allergic reactions and deaths.
An anti-VEGF agent developed in China, conbercept successfully improved visual acuity and reduced central retinal thickness and CNV area in patients with neovascular AMD in previous phase I and II studies. [Ophthalmology 2011;118:672-678; Ophthalmology 2014;121:1740-1747]
“While head-to-head studies are still needed, the PHOENIX study shows that conbercept is an effective and well-tolerated treatment for AMD with the potential to provide health outcome advantages over other [drugs of the same class],” the authors noted.
“Since anti-VEGF treatment plays an increasingly important role in treating neovascular ocular diseases, decreasing the treatment frequency and compliance burden would yield considerable social benefits and probably make a difference in promoting vision healthcare,” they added.
The study was limited by an inability to rule out the possibility that some patients in the study sample had polypoidal choroidal vasculopathy.