Benefits of ranibizumab maintained over 2 years

Two presentations from members of the MARINA study group, given at the annual meeting of the Association for Research in Vision and Ophthalmology, provided new information on ranibizumab. An antibody fragment to vascular endothelial growth factor (VEGF), the drug is designed to bind to and inhibit VEGF, a protein that plays a role in angiogenesis.

One-year efficacy results from the MARINA study had shown that ranibizumab prevented vision loss and improved vision in many patients. The 2-year data, compiled and analyzed since the last follow-up visits in late 2005, showed that there had been no decline in efficacy, said Jeffrey S. Heier, MD, a vitreoretinal specialist and clinical instructor in ophthalmology at Tufts University School of Medicine and Harvard Medical School, Boston.

Among an initial 238 patients treated with 0.3 mg of ranibizumab and 240 who received a 0.5-mg dose, 92% and 90%, respectively, lost less than 15 letters from baseline at the 2-year follow-up. Only 53% of the 238 patients in the sham treatment group lost less than 15 letters at the same timepoint.

Treatment effect

Disparities between the two treatment groups and the control group also were apparent in another outcome measure. Data showed that 26% of the group treated with 0.3 mg and 33% of group treated with 0.5 mg gained 3 ETDRS lines of vision, compared with 4% in the sham-treated group.

The mean change in visual acuity over 24 months showed gradual erosion in the sham treatment group compared with the ranibizumab-treated subjects, who had relative preservation of their vision through the second year.

The MARINA study is a phase III, multicenter, randomized, double-masked, sham injection-controlled study of the efficacy and safety of monthly intravitreal injections of ranibizumab in treating patients with minimally classic or occult choroidal neovascularization secondary to AMD.

Of the original study population of 716 participants, 89% of treated patients and 80% of sham-treated patients were available for 24-month examination. Most patients received 20 to 22 of a possible 24 monthly injections.

Photodynamic therapy or injection of pegaptanib sodium (Macugen, OSI/Eyetech Pharmaceuticals/Pfizer) was performed in some cases at the discretion of the investigators, and two participants originally randomly assigned to the sham treatment group received both. In addition, two subjects were offered ranibizumab after positive 1-year data, and 12 sham-treated subjects crossed over at months 22 and 23.