Neurotech Pharmaceuticals, Inc., today announced that it was reported in the Proceedings of the National Academy of Sciences (PNAS) (online March 28, 2011) that its product candidate NT-501 slowed progression of vision loss in patients with geographic atrophy (GA) associated with dry age-related macular degeneration (AMD) in a Phase 2 study. NT-501 is an intraocular implant that consists of human cells genetically modified to secrete ciliary neurotrophic factor (CNTF) - a nerve growth factor capable of rescuing and protecting dying photoreceptors. GA is a condition that destroys sharp central vision, often resulting in serious vision loss to one or both eyes, for which there is no available treatment.
“The study findings are very promising since both structural and functional improvements were demonstrated in a disease that is currently untreatable. These results support the initiation of larger confirmatory studies of NT-501 in patients with GA.”
The Phase 2 study was a multi-center, double-masked, sham-controlled, dose-ranging study in 51 subjects with GA. Subjects were randomly assigned to receive either a high- or low-dose NT-501 implant or sham surgery. The primary study endpoint was change in best corrected visual acuity (BCVA) at 12 months. The study results demonstrated a dose-dependent increase in retinal thickness suggesting increased photoreceptor metabolic activity. This increase was followed by visual acuity stabilization (loss of fewer than three lines of vision, or 15 letters) of 96.3% in the high-dose group compared to 83.3% in the low-dose group and 75.0% in the sham group. In a sub-group analysis of subjects with better vision at base line (20/63 or better), 100% of the high-dose group (n = 10) maintained visual acuity stabilization compared to 55.6% (p = 0.033) in the combined low- and sham-treated groups (n = 9). In this sub-group analysis, there was a 0.8 mean letter gain in the high-dose group compared to a 9.7 mean letter loss in the combined low- and sham-treated groups. Overall, there were no serious adverse events reported and the surgical procedures were well tolerated. The study results were originally reported by the Company in March 2009.
The study's lead author and one of its clinical investigators, Dr. Kang Zhang, Professor of Ophthalmology & Human Genetics, Shiley Eye Center and Director of the Institute for Genomic Medicine, University of California, San Diego commented, "The study findings are very promising since both structural and functional improvements were demonstrated in a disease that is currently untreatable. These results support the initiation of larger confirmatory studies of NT-501 in patients with GA."
Paul Sieving, MD, PhD, Director of the National Eye Institute and Principal Investigator of Neurotech's Phase 1 study of NT-501 in retinitis pigmentosa, commented that, "The results of this Phase 2 study suggest that CNTF delivered by the ECT platform may be a useful approach to slow the progression of vision loss in GA patients, and warrant further study in a larger trial of patients exhibiting early onset of this condition."
Ted Danse, Chief Executive Officer of Neurotech stated, "These results in GA demonstrate the significant opportunity of NT-501 to fill a much needed treatment void for sight-robbing retinal degenerative diseases. The data also provide further validation of our proprietary ECT technology and strongly support the introduction of additional product candidates from the platform."
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