Enhanced efficacy associated with early treatment of neovascular AMD

Los Angeles-Building on results of a study demonstrating that treatment with pegaptanib sodium (Macugen, OSI/Eyetech Pharmaceuticals) helps preserve vision and limit progression in patients with wet age-related macular degeneration (AMD), a retrospective subgroup analysis has shown that early treatment may produce even better outcomes, according to Christine R. Gonzales, MD, assistant professor of ophthalmology, Jules Stein Eye Institute, University of Los Angeles.

Dr. Gonzales is a member of the VEGF Inhibition Study in Ocular Neovascularization (V.I.S.I.O.N.) Clinical Trial Group, which conducted the original study and the subgroup analysis. Findings were published in the October/November 2005 issue of Retina.

"The V.I.S.I.O.N. trial included patients who had very large lesions and also patients with quite poor vision, and so we were interested to know if the treatment was initiated at an earlier stage of disease, whether or not we might have more of a visual gain or prevent more visual loss," Dr. Gonzales said. "Hypothetically, we would expect that would be true, because the earlier the disease is treated the less damage there is to the retinal pigment epithelium and the photoreceptors. By reversing the fluid leakage from the neovascular lesion earlier before that damage occurs, we were hoping that we would see better results."

When the investigators completed their review of the data, they found, as expected, better results when patients were treated earlier.

"We are currently conducting a prospective study looking specifically at patients with earlier neovascular disease," Dr. Gonzales said. "I think this is a really important message to get out to our patients, that is the earlier they come in for treatment, the more likely we are to reduce the visual loss and prevent blindness.

The investigators analyzed visual outcomes of patients from the V.I.S.I.O.N. study database who were treated with 0.3 mg of pegaptanib sodium every 6 weeks for 54 weeks. In the study, 1,208 subjects 50 years of age or older were enrolled at 117 sites internationally. Patients were eligible if they had subfoveal sites of choroidal neovascularization (CNV) secondary to AMD and best-corrected visual acuity (BCVA) in the study eye ranging from 20/40 to 20/320 and in the fellow eye of 20/800 or better.

Patients were randomly assigned to receive intravenous injections of pegaptanib sodium (0.3 mg, 1 mg, or 3 mg) or to receive sham injections into the eye every 6 weeks for 48 weeks.

In the subsequent exploratory analysis of the study database, the investigators evaluated disease outcomes at week 54 for patients in the 0.3 mg and sham treatment arms using two definitions of early disease, according to Dr. Gonzales.

Patients in Group 1 had a lesion size of <2 disc areas; baseline visual acuity of ≥54 ETDRS letters; no prior photodynamic therapy or thermal laser photocoagulation to the lesion; and absence of scarring or atrophy within the lesion.

Disease characteristics of Group 2 were occult with no classic CNV; absence of lipid; and better visual acuity at baseline in the fellow eye.

Group 1 included 34 (12%) of the 294 subjects who had received 0.3 mg of pegaptanib sodium and 28 (10%) of those who had received sham treatment.

Group 2 consisted of 30 (10%) of the subjects who had received pegaptanib sodium and 35 (12%) of the 296 patients who had received usual care.