A Phase 3 Multicenter, Randomized, Sham-Controlled Study to Determine the Safety and Efficacy of Renexus in Macular Telangiectasia Type 2

National Eye Institute

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Abstract

Objective: To determine the efficacy and safety of Renexus, an intraocular encapsulated cell implant secreting ciliary neurotrophic factor (CNTF), for the treatment of macular telangiectasia (MacTel) type 2. Study Population: This study is open to all persons with confirmed MacTel Type 2 who meet the Inclusion/Exclusion Criteria. Approximately 112 participants across all sites in this multicenter study will undergo study intervention. The NEI site will screen up to 12 participants, with a goal of offering study intervention to up to 6 participants. Design: This is a phase III, multi-center, single-masked, sham-controlled study of approximately 112 study participants with MacTel Type 2. Each participant will contribute a single study eye. Participants will be randomized (1:1) to receive the Renexus implant surgery or sham surgery in the study-eligible eye. All participants will be followed through 24 months. All participants will have a screening period of up to 30 days, and surgery/sham will occur within 4 weeks after completing screening. Study eyes will receive the Renexus implant surgery or sham surgery on Day 0 and will be assessed on Day 1, Week 1 ( 2 days), Month 6 ( 4weeks), Month 12 (4 weeks), Month 16 ( 4 weeks), Month 20 ( 4 weeks) and Month 24 ( 4 weeks). A telephone contact will be made at Month 1 ( 1 week), and Month 3 ( 1 week). Outcome Measures: Primary Outcome: The primary outcome will be the mean change in the area of ellipsoid zone disruption (area of photoreceptor inner segment/outer segment signal loss) from baseline through 24 months as measured by en face imaging by SD-OCT in the study eye. Secondary Outcomes: Secondary outcomes to investigate efficacy include the following, comparing participants receiving Renexus with those receiving sham intervention: Mean change in central macular thickness as measured by SD-OCT from baseline through 24 months. Proportion of eyes with > 35% increase in the area of ellipsoid zone disruption from baseline at 24 months. Mean change in aggregate sensitivity of microperimetry within the area of ellipsoid zone disruption from baseline through 24 months. Mean change in reading speed from baseline through 24 months. Mean change in the NEI Visual Function Questionnaire near activities subscale score from baseline through 24 months. Secondary outcomes to investigate safety include the following: Number of participants with persistent deterioration in visual acuity, consisting of loss of >15 letters using ETDRS testing. In 2018, we were activated as a site in the phase 3 clinical trial (18-EI-0055). We enrolled five participants, and follow up has continued during fiscal year 2021. The multicenter trial has achieved full accrual. Follow-up terminated in September 2022. Final report is due out soon. Please see the results from the previous description. In summary, treatment with NT-501 significantly reduced anatomical disease progression through 24 months in both phase 3 studies. EZ loss was reduced from baseline through month 24 was 56.4% lower in the NT-501 vs sham groups in NTMT-03-A (NT-501, 0.074 mm2 95% CI, 0.049-0.099; sham, 0.170 mm2 0.145-0.195; P<0.0001) and 29.2% lower in NTMT-03-B (NT-501, 0.116 mm2 0.088-0.144; sham, 0.164 mm2 0.134-0.193; P=0.0210). Treatment-related SAEs were uncommon and predominantly related to surgical complications. These findings demonstrate that intravitreal delivery of CNTF via ECT NT-501 is safe and effective for the treatment of MacTel.