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Clinical Trial
. 2015 Apr;159(4):659-666.e1.
doi: 10.1016/j.ajo.2014.12.013. Epub 2014 Dec 19.

Ciliary neurotrophic factor for macular telangiectasia type 2: results from a phase 1 safety trial

Emily Y Chew  1 , Traci E Clemons  2 , Tunde Peto  3 , Ferenc B Sallo  4 , Avner Ingerman  5 , Weng Tao  6 , Lawrence Singerman  7 , Steven D Schwartz  8 , Neal S Peachey  9 , Alan C Bird  10 ; MacTel-CNTF Research Group
Collaborators, Affiliations
Clinical Trial

Ciliary neurotrophic factor for macular telangiectasia type 2: results from a phase 1 safety trial

Emily Y Chew et al. Am J Ophthalmol. 2015 Apr.

Abstract

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.

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Figures

Figure 1
Figure 1
Electroretinogram (ERG) changes in eyes implanted with the ciliary neurotrophic factor (study eyes) and fellow eyes of participants with macular telangiectasia type 2 over the course of the first year of the study. Legend: The solid circles denote the study eyes while open circles denote the fellow eyes. ERG amplitude is plotted relative to the pre-implantation baseline measure.
Figure 2
Figure 2
Area of the ellipsoid zone (IS/OS) break measured in the eyes treated with ciliary neurotrophic factor (study eye) and the fellow eye of participants with macular telangiectasia type 2. Legend: Data points indicate the means (±standard error) at baseline and at 36 months post-implantation.
Figure 3
Figure 3
This ETDRS Grid was used to demarcate the 9 zones of the Optical Coherence Tomography Image in all study and fellow eyes of participants with macular telangiectasia type 2.
Figure 4
Figure 4
Change in mean retinal thickness (in μm) on each of the 9 zones of the Ocular Coherence Tomography (OCT) at 24 months compared with baseline in study eyes and fellow eyes with macular telangiectasia type 2. Legend: All zones except for zones 5 and 6 had p values <0.05 for the comparison of change in retinal thickness in the study eyes vs. the thickness in the fellow eyes. Bars indicate 95% confidence intervals.
See this image and copyright information in PMC

References

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