Sirna Reports Final Results from Phase I Study on Therapeutic for age-related Macular Degeneration

Sirna Therapeutics, Inc. has reported the final results from its recently completed Phase 1 trial for Sirna-027, a therapeutic for age-related macular degeneration (AMD).

Single ascending doses of Sirna-027 were safe and well tolerated, and all 26 patients (100%) showed visual acuity stabilization eight weeks after a single injection.

In addition, at the same time point, five of 26 patients (19%) experienced clinically significant improvement in visual acuity, indicated by an increase of at least three lines on an eye chart.

Three months after a single injection, 24 of 26 patients (92%) showed visual acuity stabilization, with four of 26 patients (15%) experiencing clinically significant improvement in visual acuity; only two of 26 patients (8%) experienced a reduction in visual acuity of three lines or more.

Importantly, a decrease in foveal thickness was observed in some patient groups, which is an indication of biological activity of Sirna-027.

"This is the first demonstration of biological activity of a chemically optimized siRNA in humans," said Sirna Chief Medical Officer Roberto Guerciolini, M.D.

"These data represent an important milestone toward the demonstration of the potential therapeutic benefit of Sirna-027 and the clinical validation of RNAi as a therapeutic modality."

The potential for a long-lasting effect on visual acuity after a single dose of Sirna-027 could be due to the unique catalytic mechanism of short interfering RNA, and could make this compound amenable to a favorable dosing regimen than other approved products.

"Less frequent dosing in this devastating disease should greatly improve patient convenience, compliance, and quality of life," said Dr. Guerciolini.

The Phase 1 study evaluated the safety, tolerability, and biological effect of single-ascending doses of Sirna-027 in patients with AMD.

A total of 26 patients with active disease were enrolled to receive a single intravitreal injection of Sirna-027 ranging from 100-1,600 micrograms.

In September 2005, Sirna and Allergan, Inc. established a Strategic Alliance in eye diseases which includes Sirna-027 for AMD.

Under the terms of the Agreement, Allergan assumed all developmental and commercialization costs for Sirna-027. Sirna and Allergan expect to initiate the Phase 2 trial during the second half of 2006.