Visual outcomes of intraocular inflammation after brolucizumab injection in Japanese patients with neovascular age-related macular degeneration.

PURPOSE: This study investigates the visual outcomes of neovascular age-related macular degeneration (nAMD) patients who developed intraocular inflammation (IOI) after intravitreal brolucizumab injection (IVBr). METHODS: We studied 285 eyes of 279 cases diagnosed with nAMD and focused on 18 eyes (6.3%) of 17 cases which developed IOI after IVBr. IVBr was performed either on the initial treatment or for switching of other anti-vascular endothelial growth factor agents during January 2020 to December 2021. We evaluated clinical features and the course of treatment of a 6-month follow-up after IOI occurred. RESULTS: Of 17 cases, 9 cases were male, 8 cases were female. Baseline logarithm of the minimum angle of resolution(logMAR) best-corrected visual acuity (BCVA) was 0.36, BCVA before IOI occurred was 0.30, and BCVA when IOI occurred was 0.43. 16 eyes (88.9%) had symptoms such as visual loss or floaters when IOI occurred. On the other hand, the remaining 2 eyes (11.1%) had no symptoms. 11 eyes (61.1%) had only IOI, while the remaining 7 eyes (38.9%) had IOI and perivascular sheathing. Steroid sub-tenon injection was performed on 1 eye (5.6%), steroid eye drops were used in 11 eyes (61.1%), and 6 eyes (33.3%) were followed-up without treatment. Neovascular AMD recurred in 16 eyes (88.9%) after IOI occurred and were treated with aflibercept. VA at 3 and 6 months after IOI occurred were significantly improved to 0.34 and 0.30, respectively (P = 0.09 at 3 months and P = 0.02 at 6 months). The symptoms of patients were improved in all cases. We were able to stop steroid treatment in all cases. CONCLUSIONS: IOI occurred in 6.3% of nAMD patients after IVBr treatment. All of which showed significant improvement from logMAR of 0.43 to 0.30 with steroid treatment or without any treatment. We should consider the possibility of IOI after IVBr as a complication, however, they have a relatively good prognosis if treated at an early stage.

Brolucizumab in recalcitrant neovascular age-related macular degeneration-real-world data in Chinese population.

This retrospective study aimed to determine the short-term efficacy and safety of brolucizumab treatment for recalcitrant neovascular age-related macular degeneration (nAMD) in a real-world setting in Taiwan. Recalcitrant nAMD patients who were treated with brolucizumab from November 2021 to August 2022 at Taipei Veterans General Hospital were included. Patients were followed for 3 months after switching to brolucizumab. The primary outcomes were changes in mean best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from baseline to the third month. The secondary outcomes included the incidence of intraocular inflammation (IOI), proportion of patients with subretinal and intraretinal fluid (SRF and IRF), and change in pigment epithelial detachment (PED) height from baseline to the third month. The significance level was considered as p < .05 in all tests. A total of 38 patients (40 eyes) with a mean (±SD) age of 76.3 (±10.84) years were included. The baseline BCVA was 0.92±0.64 logMAR, and the CRT and PED height were 329.0±171.18 and 189.8±114.94 um, respectively. The patients had a significant reduction in CRT and resolution of IRF and SRF from baseline to the third month. There were numerical improvements in mean BCVA and PED height, but they were not significant. The percentages of achieving at least 0.1, 0.2, and 0.3 logMAR (equivalent to 5, 10, 15 ETDRS letters) visual gain were 50%, 37.5%, and 30%, respectively, during the first 3 months of follow-up. No IOI occurred in these patients. This study demonstrated that brolucizumab had good short-term structural and functional efficacy in recalcitrant nAMD patients.

Central retinal artery occlusion after intravitreal brolucizumab injection for treatment-naïve neovascular age-related macular degeneration; a case report.

BACKGROUND: To report a case of central retinal artery occlusion (CRAO) after intravitreal injection of brolucizumab for a treatment-naïve neovascular age-related macular degeneration (nAMD) patient without comorbid cardiovascular disease history. CASE PRESENTATION: A 79-year-old Asian male without a cardiovascular disease history such as diabetes or hypertension underwent three times of monthly consecutive intravitreal brolucizumab injections for treatment of progressed nAMD in his left eye. Two days after the third injection, the patient presented with acute painless visual loss. Typical retinal whitening with a cherry red spot was observed on the fundus photograph, and retinal swelling with hyper-reflectivity was also identified on the optical coherence tomography (OCT) scan. On the fundus fluorescein angiography, arm-to-retina time and arteriovenous transit time were remarkedly delayed, but clinical findings suggesting an intraocular inflammation (IOI) were not observed. Therefore, CRAO was diagnosed, and anterior chamber paracentesis was administrated immediately. However, there had been no improvement in visual acuity during the follow-up period of three months, despite prolonged oral steroid and anti-platelet agent medication. CONCLUSIONS: In rare cases, patients without cardiovascular comorbidities can develop CRAO after intravitreal brolucizumab injection without gross evidence of IOI. Therefore, CRAO should always be in consideration and careful observation is required after intravitreal brolucizumab injection for nAMD patients with old age, even if the patient does not have any other cardiovascular disease history.

Switching to the aflibercept (3 mg) therapy for treatment-resistant wet age-related macular degeneration: 1-year outcomes.

This study aimed to elucidate 1-year outcomes following switching to the aflibercept (3 mg) therapy for treatment-resistant wet age-related macular degeneration (wAMD). In this prospective, open-label, non-controlled clinical trial, 18 patients with wAMD who had multiple recurrences or persistent exudation despite intravitreal injections of anti-vascular endothelial growth factor agents (except aflibercept) received a 3-mg intravitreal aflibercept injection every 4 weeks. Each patient received 3 to 8 injections. The central retinal thickness and fibrovascular pigment epithelial detachment height decreased significantly at 1 month after initiation of the aflibercept injection, and the values were 146 and 163.2 µm, respectively, at the final visit. The morphological improvement was sustained. The intraretinal and subretinal fluid was completely absorbed at the end of the follow-up. The logMAR vision increased from baseline 0.68 to 0.59 (P < .05). No ocular or systemic adverse events occurred. The intravitreal injection of 3-mg aflibercept seems to be feasible in the treatment of wAMD unresponsive to other anti-vascular endothelial growth factor agents.

Effect of intravitreal injections due to neovascular age-related macular degeneration on retinal nerve fiber layer thickness and minimum rim width: a cross sectional study.

PURPOSE: The present study tested the hypothesis that repeated anti-VEGF injections are associated with reduced retinal nerve fiber layer (RNFL) and minimum rim width (MRW) of the optic nerve head. PATIENTS AND METHODS: Sixty-six patients with a history of intravitreal injections due to neovascular age-related macular degeneration were included. RNFL and MRW were measured using optical coherence tomography (Spectralis OCT, Heidelberg Engineering, Heidelberg, Germany). RESULTS: Mean global RNFL was 90.62 µm and both RNFL as well as MRW significantly decreased with advanced age (p = 0.005 and p = 0.019, respectively). Correlating for the number of injections, no significant impact on RNFL was found globally (p = 0.642) or in any of the sectors. In contrast, however, global MRW was significantly reduced with increasing numbers of intravitreal injections (p = 0.012). The same holds true when adjusted for the confounding factor age (RNFL p = 0.566 and MRW p = 0.023). CONCLUSION: Our study shows that repeated intravitreal injections due to choroidal neovascularization seem to have a deleterious effect on MRW but not on RNFL. This suggests that MRW is a more sensitive marker than RNFL for evaluating the effect of frequent intravitreal injections on the optic nerve head since it seems to be the first structure affected.

Long-term Follow-Up and Regeneration of Retinal Pigment Epithelium (RPE) after Tears of the Epithelium in Exudative Age-Related Macular Degeneration (AMD).

BACKGROUND: The goals of this study are to evaluate potential long-term visual deterioration associated with retinal pigment epithelial (RPE) tears in patients with neovascular age-related macular degeneration (nAMD) and to find treatment-related and morphological factors that might influence the outcomes. PATIENTS AND METHODS: This retrospective study enrolled 21 eyes of 21 patients from the database of Vista Eye Clinic Binningen, Switzerland, diagnosed with RPE tears, as confirmed by spectral domain optical coherence tomography (SD-OCT), with a minimum follow-up period of 12 months. Treatment history before and after RPE rupture with anti-VEGF therapy, visual acuity, and imaging (SD-OCT) were analyzed and statistically evaluated for possible correlations. RESULTS: Mean patient age was 80.5 ± 6.2 years. The mean length of total follow-up was 39.7 ± 13.9 months. The mean pigment epithelial detachment (PED) height increased by 363.8 ± 355.5 µm from the first consultation to 562.8 ± 251.5 µm at the last consultation prior to rupture. Therefore, a higher risk of RPE rupture is implied as a result of an increase in PED height (p = 0.004, n = 14). The mean visual acuity before rupture was 66.2 ± 16.0 letters. Mean visual acuity deteriorated to 60.8 ± 18.6 letters at the first consultation after rupture (p = 0.052, n = 21). A statistically nonsignificant decrease in vision was noted in the follow-up period. After 2 years, the mean BCVA decreased by 10.5 ± 23.7 ETDRS letters (p = 0.23, n = 19). PED characteristics before rupture and amount of anti-VEGF injections after rupture did not affect the visual outcome. None of the 21 patients included in our study showed a visual improvement in the long-term follow-up. RPE atrophy increased significantly from 3.35 ± 2.94 mm2 (baseline) to 6.81 ± 6.25 mm2 over the course of 2 years (p = 0.000 013, n = 20). CONCLUSIONS: The overall mean vision decrease after rupture was without statistical significance. There was no significant change in BCVA at the 2-year follow-up, independent of the amount of anti-VEGF injections provided. In this study, there was a significant increase in RPE defect over a follow-up of 2 years, implying progression of contraction of RPE and/or macular atrophy.

Molecular Basis of Angiogenesis and its Application.

Angiogenesis, the development of new blood vessels, is a fundamental physiological process. In addition, angiogenesis plays a key role in the pathogenesis of several disorders, including cancer and eye disorders such as diabetic retinopathy and age-related macular degeneration (AMD). However, identifying the regulators of angiogenesis proved challenging. Numerous factors that stimulated angiogenesis in various bioassays were identified, but their pathophysiological role remained unclear. In 1989, we reported the isolation and cloning of vascular endothelial growth factor (VEGF, VEGF-A) as an endothelial cell-specific mitogen and angiogenic factor. The tyrosine kinases Flt-1 (VEGFR-1) and KDR (VEGFR-2) were subsequently identified as VEGF receptors. Loss of a single vegfa allele results in defective vascularization and embryonic lethality in mice, emphasizing the essential role of VEGF in the development of blood vessels. Subsequently, we reported that anti-VEGF monoclonal antibodies block growth and neovascularization in tumor models. These findings paved the way for the clinical development of a humanized anti-VEGF antibody and other VEGF inhibitors for cancer therapy. To date, several VEGF inhibitors represent standard of care for colorectal cancer and other difficult to treat malignancies. VEGF is also implicated in intraocular neovascularization associated with retinal disorders as well as neovascular AMD. Our group developed a humanized anti-VEGF-A antibody fragment (ranibizumab) for the treatment of wet AMD. Ranibizumab not only maintained but also improved visual acuity and has been approved worldwide for the treatment of wet AMD and other neovascular disorders. Other VEGF inhibitors, including bevacizumab and aflibercept, have also resulted in significant clinical benefits. Today anti-VEGF drugs represent the most effective therapy for intraocular neovascularization. Current research addresses the need to reduce the frequency of intravitreal injections as well the identification of additional pro-angiogenic pathways that could result in improving therapeutic outcomes.

Gene therapy for age-related macular degeneration: potential, feasibility, and pitfalls.

PURPOSE OF REVIEW: The landscape for age-related macular degeneration (AMD) is rapidly changing with addition of biosimilars and now United States Food and Drug Administration (FDA) approved nonneovascular AMD (nnAMD) treatment options. These developments have inspired a burgeoning pipeline of gene therapy approaches focused on similar antivascular endothelial growth factors (VEGF) and complement related pathways. Historic and more recent setbacks in the gene therapy pipeline, including intraocular inflammatory reactions, have raised important concerns for adverse events related to AMD therapeutics both for gene and nongene approaches. The specific clinical profile of these therapeutics approaching later stage clinical trials are complex and under active investigation; however, these options hold promise to disrupt the current landscape and change management paradigms for one of the leading causes of vision loss worldwide. RECENT FINDINGS: This review covers current gene therapy approaches for neovascular AMD (nAMD) and nnAMD. Intravitreal, suprachoroidal, and subretinal delivery routes are discussed with attention to technical procedure, capabilities for transgene delivery to target tissue, immunogenicity, and collateral effects. Suprachoroidal delivery is an emerging approach which may bridge some of the practical drawbacks for intravitreal and subretinal methods, though with less elaborated immunologic profile. In parallel to delivery modification, viral vectors have been cultivated to target specific cells, with promising enhancements in adeno-associated viral (AAV) vectors and persistent interest in alternate viral and nonviral delivery vectors. Ongoing questions such as steroid or immunosuppressive regimen and economic considerations from a payer and societal perspective are discussed. SUMMARY: The present review discusses emerging gene therapy options which could foster new, more durable nAMD and nnAMD therapeutics. These options will need refinement with regards to route, vector, and dosage, and specialists must decipher the specific clinical risk benefit profile for individual patients. Ongoing concerns for immunogenicity or dosage related adverse events could stifle progress, while further vector development and refined delivery techniques have the potential to change the safety and efficacy of currently options in the pipeline.

Tear cytokine levels are reduced in patients treated with intravitreal injections.

PURPOSE: To investigate cytokine levels in the tear fluid of patients receiving serial intravitreal injections (IVI) with anti-vascular endothelial growth factor (anti-VEGF) for neovascular age-related macular degeneration (nAMD). METHODS: Concentrations of six cytokines (IFN-γ, IL-1ß, IL-6, IL-8, TNF and VEGF) in tears of patients receiving anti-VEGF in one eye were assayed using multiplex cytometric bead array. The fellow untreated eye served as control. Tear sampling was performed on a single occasion at a minimum of four weeks after IVI. Patients underwent a pre-IVI antisepsis protocol with povidone-iodine. RESULTS: Tear fluid from thirty patients with a mean age of 78.8 years (range 58-90) was assayed. Subjects received a median of 43.5 (range 22-106) IVI in one eye. The median level of IFN-γ was 0.33 (interquartile range (IQR) 0.22-0.52) pg/mg of total protein in injected eyes versus 0.41 (IQR 0.21-1.05) pg/mg in fellow eyes (p = 0.017). For TNF, a median level of 0.12 (IQR 0.08-0.18) pg/mg of total protein was found in injected eyes versus 0.14 (IQR 0.07-0.33) pg/mg of total protein in fellow eyes (p = 0.019). There were no differences between injected and fellow eyes regarding the levels of IL-1ß, IL-6, IL-8 and VEGF. CONCLUSION: Tear fluid in eyes receiving serial IVI with anti-VEGF and preoperative povidone-iodine antisepsis constitutes lower levels of the pro-inflammatory cytokines IFN-γ and TNF compared to fellow eyes. This provides biochemical support of previous findings of reduced signs of inflammation and healthier tear film parameters in patients treated with serial IVI.

Impact of Prolonged Persisting Subretinal Fluid on the Outcome of Aflibercept Treatment in Neovascular Age-Related Macular Degeneration.

Purpose: To evaluate the effect of prolonged residual subretinal fluid (SRF) on the outcomes of aflibercept treatment in neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). Methods: This retrospective study included patients diagnosed with neovascular AMD or PCV who presented with fovea-involving residual SRF that persisted for a minimum of 6 months while undergoing aflibercept treatment. Changes in best-corrected visual acuity (BCVA) during persistent SRF were evaluated. The factors associated with the risk of visual deterioration during this period were also investigated. Results: In total, 135 patients were included in this study. During this period, the duration of the presence of residual SRF was 17.1 ± 10.3 months and mean injection interval was 2.6 ± 0.7 months. The mean BCVA was changed from 0.30 ± 0.23(Snellen equivalents, 20/39) to 0.36 ± 0.28 (20/45). In 18 (13.3%) patients, ≥2 lines of visual deterioration was noted. The duration of persisting SRF (P = 0.008) and mean height of SRF (P = 0.005) were significantly associated with a high risk of visual deterioration. Among the 80 patients with mean SRF height <100 µm, ≥2 lines of visual deterioration were noted in 4 (5.0%) patients. Among 41 patients with the mean SRF height ≥100 µm and <200 µm and 14 patients with the mean SRF height ≥200 µm, the visual deterioration was noted in 8 (19.5%) and 6 (42.9%) patients, respectively. Conclusions: In cases of neovascular AMD or PCV in which SRF persists without complete resolution during treatment, minimizing the duration of persistent SRF and mean height of SRF is recommended to mitigate the risk of visual deterioration. ClinicalTrials.gov Identifiers: NCT05662943 (https://clinicaltrials.gov/study/NCT05662943?cond=type%201%20macular%20neovascularization&rank=2).

Phase 2 Trial Evaluating Minocycline for Geographic Atrophy in Age-Related Macular Degeneration: A Nonrandomized Controlled Trial.

Importance: Existing therapies to slow geographic atrophy (GA) enlargement in age-related macular degeneration (AMD) have relatively modest anatomic efficacy, require intravitreal administration, and increase the risk of neovascular AMD. Additional therapeutic approaches are desirable. Objective: To evaluate the safety and possible anatomic efficacy of oral minocycline, a microglial inhibitor, for the treatment of GA in AMD. Design, Setting, and Participants: This was a phase 2, prospective, single-arm, 45-month, nonrandomized controlled trial conducted from December 2016 to April 2023. Patients with GA from AMD in 1 or both eyes were recruited from the National Institutes of Health (Bethesda, Maryland) and Bristol Eye Hospital (Bristol, UK). Study data were analyzed from September 2022 to May 2023. Intervention: After a 9-month run-in phase, participants began oral minocycline, 100 mg, twice daily for 3 years. Main Outcomes and Measures: The primary outcome measure was the difference in rate of change of square root GA area on fundus autofluorescence between the 24-month treatment phase and 9-month run-in phase. Results: Of the 37 participants enrolled (mean [SD] age, 74.3 [7.6] years; 21 female [57%]), 36 initiated the treatment phase. Of these participants, 21 (58%) completed at least 33 months, whereas 15 discontinued treatment (8 by request, 6 for adverse events/illness, and 1 death). Mean (SE) square root GA enlargement rate in study eyes was 0.31 (0.03) mm per year during the run-in phase and 0.28 (0.02) mm per year during the treatment phase. The primary outcome measure of mean (SE) difference in enlargement rates between the 2 phases was -0.03 (0.03) mm per year (P = .39). Similarly, secondary outcome measures of GA enlargement rate showed no differences between the 2 phases. The secondary outcome measures of mean difference in rate of change between 2 phases were 0.2 letter score per month (95% CI, -0.4 to 0.9; P = .44) for visual acuity and 0.7 µm per month (-0.4 to 1.8; P = .20) for subfoveal retinal thickness. Of the 129 treatment-emergent adverse events among 32 participants, 49 (38%) were related to minocycline (with no severe or ocular events), including elevated thyrotropin level (15 participants) and skin hyperpigmentation/discoloration (8 participants). Conclusions and Relevance: In this phase 2 nonrandomized controlled trial, oral minocycline was not associated with a decrease in GA enlargement over 24 months, compared with the run-in phase. This observation was consistent across primary and secondary outcome measures. Oral minocycline at this dose is likely not associated with slower rate of enlargement of GA in AMD.

Prediction of neovascular age-related macular degeneration recurrence using optical coherence tomography images with a deep neural network.

Neovascular age-related macular degeneration (nAMD) can result in blindness if left untreated, and patients often require repeated anti-vascular endothelial growth factor injections. Although, the treat-and-extend method is becoming popular to reduce vision loss attributed to recurrence, it may pose a risk of overtreatment. This study aimed to develop a deep learning model based on DenseNet201 to predict nAMD recurrence within 3 months after confirming dry-up 1 month following three loading injections in treatment-naïve patients. A dataset of 1076 spectral domain optical coherence tomography (OCT) images from 269 patients diagnosed with nAMD was used. The performance of the model was compared with that of 6 ophthalmologists, using 100 randomly selected samples. The DenseNet201-based model achieved 53.0% accuracy in predicting nAMD recurrence using a single pre-injection image and 60.2% accuracy after viewing all the images immediately after the 1st, 2nd, and 3rd injections. The model outperformed experienced ophthalmologists, with an average accuracy of 52.17% using a single pre-injection image and 53.3% after examining four images before and after three loading injections. In conclusion, the artificial intelligence model demonstrated a promising ability to predict nAMD recurrence using OCT images and outperformed experienced ophthalmologists. These findings suggest that deep learning models can assist in nAMD recurrence prediction, thus improving patient outcomes and optimizing treatment strategies.

Relative yield of retinal imaging versus clinical exam in following neovascular exudative age related macular degeneration.

PURPOSE: To compare therapeutic decisions between 3 diagnostic protocols and to assess the need for in-person physical doctor-patient encounter in follow up and treatment of neovascular exudative age-related macular degeneration (AMD). METHODS: Analysis of 88 eyes of 88 unique patients with neovascular AMD who were routinely followed at our medical retina clinic. A retinal specialist reviewed all images in advance and wrote his decisions. He later attended an in-person encounters with all patients and documented his decisions. Masking was done by not exposing any identifying information to the specialist and by randomizing patient's images order before the in-person encounter. Therapeutic decisions regarding intravitreal injections intervals and agent selection were made based on three protocols: (1) optic coherence tomography (OCT); (2) OCT/Ultra-widefield (UWF) color image; (3) OCT/UWF/full clinical exam. Visual acuity (VA) was incorporated into all protocols. RESULTS: We found an agreement of 93% between those protocols regarding the intervals of injections, and of 100% regarding injection agent selection. When comparing OCT, OCT/UWF and OCT/UWF/clinical exam guided decision making, there were no discrepancies between OCT and OCT/UWF. There were 6 out of 88 discrepancies (7%) between OCT/UWF and OCT/UWF/clinical exam. Of those 6 discrepancies, all were regarding intervals (Bland-Altman bias = - 0.2386). All discrepancies between OCT/UWF and OCT/UWF/Clinical exam were due to patients' preferences, socioeconomic issues and fellow eye considerations, addressed during the face-to-face encounter with patients. Physical examination itself did not affect decision making. CONCLUSIONS: Neovascular exudative AMD follow up and treatment decisions can be guided by VA and OCT, with UWF adding important information regarding macula and peripheral retina, but rarely affecting decision making. However, decision making may also be driven by patients' preferences and other considerations that are being made only during the face-to-face visit and discussion. Thus, every approach supporting imaging only decision making, must take these factors into account.

[Challenges and strategies in the treatment of neovascular age-related macular degeneration].

Neovascular age-related macular degeneration (nAMD) is a leading cause of blindness in the elderly, and anti-vascular endothelial growth factor (VEGF) therapy is currently the primary treatment approach. However, the real-world effectiveness of nAMD treatment is not always satisfactory and faces various challenges. Frequent administration and follow-up burdens can lead to decreased patient compliance during long-term treatment, resulting in suboptimal outcomes. Some lesions exhibit poor or no response to anti-VEGF treatment, leading to difficulties in maintaining or even declining visual acuity. Factors such as lesion fibrosis and tissue atrophy can contribute to visual deterioration. Therefore, standardizing and individualizing treatment plans, along with enhancing comprehensive monitoring and management throughout the disease course, are crucial improvement measures. The evidence-based guidelines for diagnosis and treatment of age-related macular degeneration in China, released in 2023, provide guidance for standardized clinical diagnosis and treatment. Meanwhile, research and development of new drugs and administration methods are anticipated for the future.

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.