Twelve-month results of the phase II FILLY trial showed that the administration of APL-2, a complement C3 inhibitor (Apellis Pharmaceuticals), slowed the growth rate of geographic atrophy (GA) in patients.
Researchers also found that while APL-2 slowed the growth rate of GA–independent of any genetic biomarkers–it also appeared to increase the risk of new onset age-related macular degeneration (AMD), although this did not have an adverse effect on visual outcomes. There also were no safety issues that would preclude further development.
In presenting the results, David Boyer, MD, Retina-Vitreous Associates Medical Group, Los Angeles, said it is well known that the complement C3 inhibitor plays a role in the development of AMD.
Dr. Boyer explained that C3 plays a central role in the complement cascade. When C3 is inhibited, as was done in this study with APL-2, all 3 activation pathways of complement are blocked, and prevents cleavage into C3a and C3b. This also prevents the downstream effects of complement, including formation of the membrane attack complex (MAC).