A Study of an Encapsulated Cell Technology (ECT) Implant for Patients With Atrophic Macular Degeneration

Histopathologic studies of multiple forms of retinal neurodegenerative diseases have demonstrated the possibility of using the neurotrophic factor CNTF as an effective approach to reducing photoreceptor cell loss. Consequently, it had been hypothesized that the use of the implanted NT-501 capsule, which secretes CNTF into the vitreous, might be beneficial in people with atrophic macular degeneration. The purpose of this pilot study was to accumulate preliminary data on the effect of the intraocular NT-501 implant on visual acuity in patients with atrophic macular degeneration. The study had a double-masked, multi-center, randomized, parallel group design. Eligible patients were randomized on a 2:1:1 basis to the higher CNTF output NTC-201-6A.02 implant, the lower CNTF output NTC-201-10.02 implant or to sham surgery, respectively. The surgeon designated by the Principal Investigator (PI), the PI, vision examiners, reading center graders, and patients were all masked as to the dose of the implant. The patients and the vision examiners were masked as to which treatment was received. Approximately 48 patients with geographic atrophy compatible with category 3 or 4 AMD were planned to be enrolled. All patients were to be followed clinically for 18 months. Patients randomized to the CNTF implants were implanted at baseline, had the option of being explanted at or after 12 months, and all were followed clinically for 18 months. Follow-up for safety occurred throughout the study period.