Gene therapy for neovascular age-related macular degeneration by subretinal delivery of RGX-314: a phase 1/2a dose-escalation study.

BACKGROUND: Frequent anti-vascular endothelial growth factor A (VEGF-A) injections reduce the risk of rapid and severe vision loss in patients with neovascular age-related macular degeneration (nAMD); however, due to undertreatment, many patients lose vision over time. New treatments that provide sustained suppression of VEGF-A are needed. RGX-314 (currently known as ABBV-RGX-314) is an adeno-associated virus serotype 8 vector that expresses an anti-VEGF-A antigen-binding fragment, which provides potential for continuous VEGF-A suppression after a single subretinal injection. We report results on the safety and efficacy of subretinal injection of RGX-314 in patients with nAMD. METHODS: For this open-label, multiple-cohort, multicentre, phase 1/2a, dose-escalation study conducted at eight sites in the USA, we enrolled participants with nAMD aged 50-89 years who had previously been treated with anti-VEGF injections into five cohorts (with five different doses of RGX-314). To be eligible, participants had to have macular neovascularisation secondary to nAMD with subretinal or intraretinal fluid in the centre subfield, be pseudophakic (after cataract removal), and have a best-corrected visual acuity (BCVA) in the study eye between 20/63 and 20/400 for the first participant in each cohort and between 20/40 and 20/400 for others. Subretinal injection of RGX-314 was done without a pre-bleb by a wet-laboratory-trained vitreoretinal surgeon. Cohort 1 received 3 × 109 genome copies per eye, cohort 2 received 1 × 1010, and cohort 3 received 6 × 1010. Two additional dose cohorts (cohort 4: 1·6 × 1011; cohort 5: 2·5 × 1011) were added. Participants were seen 1 day and 1 week after administration of RGX-314, and then monthly for 2 years (up to week 106). The primary outcome was safety of RGX-314 delivered by subretinal injection up to week 26. This analysis includes all 42 patients enrolled in the study. This study is registered with ClinicalTrials.gov, NCT03066258. FINDINGS: Between May 12, 2017, and May 21, 2019, we screened 110 patients for eligibility and enrolled 68. 42 participants demonstrated the required anatomic response to intravitreal ranibizumab and then received a single RGX-314 injection (dose range 3 × 109 to 2·5 × 1011 genome copies per eye) and were followed up for 2 years. There were 20 serious adverse events in 13 participants, of which one was possibly related to RGX-314: pigmentary changes in the macula with severe vision reduction 12 months after injection of RGX-314 at a dose of 2·5 × 1011 genome copies per eye. Asymptomatic pigmentary changes were seen in the inferior retinal periphery several months after subretinal injection of RGX-314 most commonly at doses of 6 × 1010 genome copies per eye or higher. There were no clinically determined immune responses or inflammation beyond that expected following routine vitrectomy. Doses of 6 × 1010 genome copies or higher resulted in sustained concentrations of RGX-314 protein in aqueous humour and stable or improved BCVA and central retinal thickness with few or no supplemental anti-VEGF-A injections in most participants. INTERPRETATION: Subretinal delivery of RGX-314 was generally well tolerated with no clinically recognised immune responses. RGX-314 gene therapy provides a novel approach for sustained VEGF-A suppression in patients with nAMD that has potential to control exudation, maintain vision, and reduce treatment burden after a single administration. Results from this study informed the pivotal programme to evaluate RGX-314 in patients with nAMD. FUNDING: RegenxBio.

Suprachoroidal gene transfer with nonviral nanoparticles in large animal eyes.

Suprachoroidal nonviral gene therapy with biodegradable poly(ß-amino ester) nanoparticles (NPs) provides widespread expression in photoreceptors and retinal pigmented epithelial (RPE) cells and therapeutic benefits in rodents. Here, we show in a human-sized minipig eye that suprachoroidal injection of 50 µl of NPs containing 19.2 µg of GFP expression plasmid caused GFP expression in photoreceptors and RPE throughout the entire eye with no toxicity. Two weeks after injection of 50, 100, or 200 µl, there was considerable within-eye and between-eye variability in expression that was reduced 3 months after injection of 200 µl and markedly reduced after three suprachoroidal injections at different locations around the eye. Reduction of bacterial CpG sequences in the expression plasmid resulted in a trend toward higher expression. These data indicate that nonviral suprachoroidal gene therapy with optimized polymer, expression plasmid, and injection approach has potential for treating photoreceptors throughout the entire retina of a human-sized eye.

Heterogeneity in disease activity, frequency of treatments, and visual outcomes among patients with retinal vein occlusion: relationship between injection need and vision with as-needed ranibizumab.

BACKGROUND/AIMS: We characterised the relationships between monitoring frequency, ranibizumab injection need and vision in patients receiving as-needed (pro re nata; PRN) ranibizumab for macular oedema due to branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO) in this post-hoc analysis of SHORE and HORIZON. METHODS: Patients aged 18 years and older with macular oedema due to BRVO/CRVO were included in this analysis. Injection frequency and best-corrected visual acuity (BCVA) were evaluated by PRN injection frequency in the PRN dosing phase (months (M) 7-15) of SHORE and through 12 months of HORIZON. Prespecified PRN re-treatment criteria for each trial were based on protocol-prespecified BCVA and optical coherence tomography outcomes. RESULTS: After the initial 7 monthly ranibizumab injections, patients in SHORE gained a mean of 18.3 letters from baseline. Patients randomised to PRN, on average, maintained these gains. However, some patients experienced additional mean gains, whereas others suffered losses (range 4.0 (95% CI 0.7 to 7.3) to -4.6 (95% CI -11.8 to 2.6) letters in patients who received 0 and 6-7 PRN injections, respectively). In BRAVO and CRUISE (lead-in trials), patients experienced mean gains from baseline to M6 (monthly dosing) of 19.3 and 15.0 letters, respectively, with gains maintained with PRN from M6 to M12. However, mean BCVA changes from baseline to M12 varied in HORIZON (range -0.4 (95% CI -2.5 to 1.6) to -3.6 (95% CI -6.2 to -1.0) letters in patients who received zero and six injections, respectively, during the preceding PRN phase of BRAVO and CRUISE). CONCLUSION: The BRVO/CRVO population is heterogenous with a varied response to ranibizumab treatment.