The early improvement in visual acuity in diabetic retinopathy patients treated with the selective anti-vascular endothelial growth factor (VEGF) inhibitor pegaptanib sodium injection (MacugenR) is maintained at follow-up nearly a year later, researchers announced at the European Society of Ophthalmology (ESO) 2007.

Erdem Ergun, MD, Sanatorium Hera and Medical University in Graz, Austria, and associates elsewhere, reported the results of an open-label extension follow-up of 172 patients treated with pegaptanib (0.3 mg, 1 mg, or 3 mg) or sham injections, with laser photocoagulation permitted as needed. All participants in the trial had diabetic retinopathy and significant diabetic macular edema.

Results at 36 weeks showed that pegaptanib was associated with improved visual acuity, reduced retinal thickness, and regression of retinal neovascularization.

New data through week 82, which is about 46 weeks after injections were stopped, showed ongoing benefit with pegaptanib and the absence of any safety concerns.

“The data are important because diabetic retinopathy is the number one cause of blindness in adults in developed countries, and all type 1 and type 2 diabetics are at increased risk that worsens over time,” said Dr. Ergun, who is head of Retinal Services at KA Sanatorium Hera. Dr. Ergun reported the findings on behalf of the MacugenR Diabetic Retinopathy Study Group.

Specifically, the results of both the randomized and extension phase documented a visual acuity gain of 10 or more letters in 34% of the pegaptanib 0.3 mg dose group compared with 10% of the sham group and a gain of at least 15 letters in 18% and 7% of the two groups, respectively.

Mean central retinal thickness decreased more in the 0.3 mg pegaptanib group at each time point.

Overall, 13 patients in the pegaptanib groups and three in the sham group had retinal neovascularization in the study eyes at baseline. Eight of the pegaptanib-treated patients, or 62%, had regression of neovascularization versus none of the three sham-treated patients. Neovascularization regression was maintained in five of the eight pegaptanib-treated patients at week 52.

Pegaptanib was well tolerated. There was one case of endophthalmitis and no evidence of an increased risk of retinal detachment, vascular occlusion, vitreous hemorrhage, or any systemic side effects.

Dr. Ergun said that diabetic retinopathy is presently treated using laser surgery which is effective but generally stabilizes visual function without improvement. Another therapeutic agent is intravitreal triamcinolone which is, however, only “temporarily effective” and leads to cataract formation and significant ocular pressure increases.

Pegaptanib is indicated for the treatment of neovascular (wet) age-related macular degeneration.

The study was sponsored by (OSI) Eyetech, and Pfizer Inc.

By Jill Stein
Jillstein03 at cs.com