Two-year intraocular delivery of ciliary neurotrophic factor by encapsulated cell technology implants in patients with chronic retinal degenerative diseases.

Purpose: To evaluate the pharmacokinetics of ciliary neurotrophic factor (CNTF) delivered over a period of up to 2 years by an intraocular encapsulated cell technology (ECT) implant in patients with retinitis pigmentosa (RP) and geographic atrophy (GA).

Methods: Patients from phase 1 RP (CNTF1); phase 2 GA (CNTF2); and phase 2 late and early stage RP (CNTF3, and CNTF4) studies received an ECT-CNTF implant, designated as "NT-501," in one eye. Per protocol, all implants (n = 10) were removed at 6 months from the CNTF1 study patients.