[Japan phase 3 study of pegaptanib sodium in patients with diabetic macular edema]

To evaluate the efficacy and safety of intravitreal injections of pegaptanib sodium in subjects with diabetic macular edema (DME).

There were 243 subjects with DME who were randomized to receive, every 6 weeks, either an intravitreal injection of pegaptanib sodium or a sham injection. The study was double-masked for the first 24 weeks, and then an open label phase continued to week 54. The primary efficacy endpoint was evaluated at week 24, and safety was assessed throughout the 54 weeks.

The proportion of subjects who experienced more than 10 letters improvement of visual acuity in ETDRS chart from baseline to week 24 was statistically significantly greater (p-value = 0.0003) in the pegaptanib sodium group, 20.3%, than in the sham group, 5.0%. The incidence of treatment-related adverse events was similar between the treatment groups (pegaptanib sodium group: 10.6%, sham group: 10.0%). The reported adverse events were mainly mild or moderate ophthalmic events and related to the injection procedure. During open-label phase up to 54 weeks, no new safety concerns were identified compared with the double-masked phase. However, in light of the issue concerning proper maintenance of masking of the study treatments, the study was not considered as a well-controlled, double-masked study.