Take-home message: A novel anti-vascular endothelial growth factor agent, RTH258, produced rapid and sustained improvements in visual acuity and central subfield thickness and was non-inferior to aflibercept in a phase II trial.
Cleveland—Positive results were achieved in a phase II study investigating RTH258 (Alcon Laboratories), a novel anti-vascular endothelial growth factor (VEGF) agent for the treatment of neovascular age-related macular degeneration (AMD).
A pivotal trial program will soon be under way, according to Lawrence J. Singerman, MD, clinical professor of ophthalmology, Case Western Reserve University, Cleveland.
Known as the OSPREY trial, the study had a randomized, double-masked design and compared RTH258 6 mg with aflibercept 2 mg (Eylea, Regeneron) in 89 previously untreated patients. Both agents were initially dosed every 8 weeks through week 32, and then the dosing interval was increased to 12 weeks with follow-up continuing to week 56. Throughout the study, patients were evaluated monthly and could receive rescue treatment as needed.
The study met its primary endpoint by demonstrating non-inferiority of RTH258 compared with aflibercept for improving mean visual acuity at week 12.
Comparison of VA gains
Non-inferiority of RTH258 versus aflibercept was also achieved in comparisons of mean visual acuity gain at week 16 and improvements in central subfield thickness, although fewer rescue treatments were needed in the RTH258 arm.
After dosing was switched to every 12 weeks, patients in the RTH258 group continued to require fewer rescue treatments (60 versus 94). Visual acuity gains and central subfield thickness outcomes were again similar in the two study groups at week 56.