Ciliary Neurotrophic Factor for Macular Telangiectasia Type 2: Results From a Phase 1 Safety Trial

• Published in: American journal of ophthalmology 2015-04, Vol.159 (4), p.659-666.e1
• Main Authors: Chew, Emily Y, Clemons, Traci E, Peto, Tunde, Sallo, Ferenc B, Ingerman, Avner, Tao, Weng, Singerman, Lawrence, Schwartz, Steven D, Peachey, Neal S, Bird, Alan C
• Format: Article
• Language: English
• Subjects: Aged; Autoantibodies - immunology; Ciliary Neurotrophic Factor - administration & dosage; Ciliary Neurotrophic Factor - adverse effects; Ciliary Neurotrophic Factor - immunology; Drug Delivery Systems; Electroretinography; Enzyme-Linked Immunosorbent Assay; Female; Fluorescein Angiography; Humans; Intravitreal Injections; Macular degeneration; Male; Medical research; Middle Aged; Ophthalmology; Retina; Retina - physiopathology; Retinal Telangiectasis - immunology; Retinal Telangiectasis - physiopathology; Retinal Telangiectasis - therapy; Studies; Tomography, Optical Coherence; Visual Acuity - physiology; Visual Fields - physiology
• ISSN: 0002-9394; 1879-1891
• DOI: 10.1016/j.ajo.2014.12.013

Purpose To evaluate the safety and tolerability of intraocular delivery of ciliary neurotrophic factor (CNTF) using an encapsulated cell implant for the treatment of macular telangiectasia type 2. Design An open-label safety trial conducted in 2 centers enrolling 7 participants with macular telangiectasia type 2. Methods The participant's more severely affected eye (worse baseline visual acuity) received the high-dose implant of CNTF. Patients were followed for a period of 36 months. The primary safety outcome was a change in the parameters of the electroretinogram (ERG). Secondary efficacy outcomes were changes in visual acuity, en face measurements of the optical coherence tomography of the disruption in the ellipsoid zone, and microperimetry when compared with baseline. Results The ERG findings demonstrated a reduction in the amplitude of the scotopic b-wave in 4 participants 3 months after implantation (month 3). All parameters returned to baseline values by month 12 and remained so at month 36 with no clinical impact on dark adaptation. There was no change in visual acuity compared with baseline. The area of the defect as measured functionally by microperimetry and structurally by the en face OCT imaging of the ellipsoid zone loss appeared unchanged from baseline. Conclusions The intraocular delivery of CNTF in the encapsulated cell implant appeared to be safe and well tolerated in eyes with macular telangiectasia type 2. Further evaluation in a randomized controlled clinical trial is warranted to test for efficacy.