Neovascular age-related macular degeneration (nAMD) is well-known as a heterogeneous disease with variable natural history and variable treatment response, said Carl D. Regillo, MD, FACS. Many patients do well without monthly treatment as noted in HARBOR PRN arms.
“It’s well known patients in this study did well on both ends of the spectrum,” Dr. Regillo said. “Frequent fixed dosing, as were done in the registration studies (for aflibercept [Eylea, Regeneron Pharmaceuticals] and ranibizumab [Lucentis, Genentech]), does lead to some degree of overtreatment and overtreatment does translate into increased expense burden and risk.”
Dr. Regillo is director of the Retina Service, Wills Eye Hospital, Philadelphia.
Individualized treatment in attempts to avoid overtreatment can be accomplished by PRN or treat-and-extend or some combination of the two, “with the goal of suppression of both choroidal neovascularization growth and exudation and it’s going to require frequent optical coherence tomography (OCT) testing with a zero tolerance for exudation,” Dr. Regillo said.
Studies support PRN
Both the CATT and IVAN studies confirmed PRN treatment “does work well in many patients,” Dr. Regillo said. For many patients, PRN regimens are impractical as dosing is reduced, but not office visits.
“Even with close monitoring, the best available imaging techniques–and a zero tolerance for any signs of recurrent exudation–CATT, IVAN, and HARBOR studies indicated that the PRN approach doesn’t control the disease as well over time,” Dr. Regillo explained. “The visual improvements that were achieved early in the course of treatment didn’t hold up as well as continuous treatment.”
Some vision loss in the long-term study cohorts may be related to undertreatment, but small lesions at baseline and baseline vision are predictors of final visual acuity.
“If patients start off with good vision, they’ll end with even better vision,” Dr. Regillo said.
In a recently published study, in patients with 20/40 or better baseline vision, the vision can be maintained over 2 years “in better than 75% of patients,” he added.