Biosimilar CT-P42 (Celltrion) has shown therapeutic equivalence to reference aflibercept (Eylea; Genentech) in improving best-corrected visual acuity (BCVA) in adults with diabetic macular edema (DME), according to a phase 3 clinical trial. The study, published in Ophthalmology Retina, evaluated the efficacy and equivalence of CT-P42 to aflibercept, with promising interim results at 24 weeks and further data expected at 52 weeks.
DME, a major cause of vision loss in diabetes, results from retinal vascular damage and vascular endothelial growth factor (VEGF) overexpression. Aflibercept addresses this as a high-affinity VEGF inhibitor approved for DME treatment. CT-P42 has received approval in South Korea and is under review by the European Medicines Agency and the FDA.
The study included 348 patients with DME, randomized to receive either CT-P42 or reference aflibercept via intravitreal (IVT) injections. The dosing regimen consisted of 5 initial doses every 4 weeks, followed by 4 doses every 8 weeks. Therapeutic equivalence was demonstrated for the primary end point, with the change from baseline in BCVA at week 8 showing an estimated treatment difference of 0.58 letters (95% CI, −0.73 to 1.88).
Both treatment groups exhibited comparable improvements in BCVA through week 24, with secondary end points also showing similarity between groups. Safety profiles were comparable, with most treatment-emergent adverse events (TEAEs) being grade 1 or 2 in intensity. The proportion of ocular TEAEs was slightly lower in the CT-P42 group.
Limitations of the trial included a small PK analysis group, limited racial diversity among participants, and data availability only up to week 24. The authors concluded that future studies should investigate the long-term efficacy and safety of CT-P42 in routine clinical practice after marketing approval.
