Abstract
Purpose :
To assess functional and structural progression after 48 months of treatment with ciliary neurotrophic factor (CNTF) delivered using an encapsulated cell implant for the treatment of macular telangiectasia (MacTel) Type 2.
Methods :
MacTel Type 2 affects both eyes and is characterized by retinal opacification, vascular telangiectasis, right-angle venules, intra-retinal crystalline deposits, foveal thinning, retinal pigment epithelial hypertrophy, and, in some cases, intra-/sub-retinal neovascularization. This neurodegenerative disease is considered to result from the loss of Mueller cells, resulting in loss of photoreceptors. A Phase 1 open label, non-randomized Phase 1 study was conducted to assess ocular safety after implantation of the CNTF-secreting capsule. Secondary efficacy outcomes included change in visual acuity, optical coherence tomography en face measurements of the disruption in the ellipsoid zone, and microperimetry comparisons between baseline and 48 months of treatment.
Results :
A total of seven participants were enrolled in the study. The mean ± standard deviation (SD) change in best corrected visual acuity (BCVA, 48 months - baseline) was 1.17 ± 0.48 (p=0.06) letters in CNTF implanted (study) eyes versus -5.50 ± 1.88 (p=0.03) letters in fellow eyes. The difference between study/fellow eyes met statistical significance (6.67 ± 1.52; 95% CI: 2.32 – 9.13; p=0.007). All study eyes experienced an increase of 10dB in at least one point as measured by microperimetry compared with 1 of 5 fellow eyes (p=0.05). The mean change in ellipsoid zone viewed "en face" at 48 months was 0.27 ± 0.13 mm2 (p=0.10) in the study eyes and 0.60 ± 0.30 mm2 (p=0.11) in the fellow eyes. The difference between study/fellow eye did not meet statistical significance (mean difference=-0.33 ± 0.25; 95% CI: 0.34 – 1.62; p=0.26).
Conclusions :
These data provide preliminary data on potential efficacy parameters to assess the CNTF implant as a treatment for MacTel Type 2 in future studies.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.