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Translational Vision Science &... Nov 2023This systematic review evaluates the safety and efficacy of ocular gene therapy using adeno-associated virus (AAV). (Meta-Analysis)
Meta-Analysis
PURPOSE
This systematic review evaluates the safety and efficacy of ocular gene therapy using adeno-associated virus (AAV).
METHODS
MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched systematically for controlled or non-controlled interventional gene therapy studies using key words related to retinal diseases, gene therapy, and AAV vectors. The primary outcome measure was safety, based on ocular severe adverse events (SAEs). Secondary outcome measures evaluated efficacy of the therapy based on best corrected visual acuity (BCVA) and improvements in visual sensitivity and systemic involvement following ocular delivery. Pooling was done using a DerSimonian Laird random effects model. Risk of bias was assessed using the Cochrane Risk of Bias Tool, version 1.
RESULTS
Our search identified 3548 records. Of these, 80 publications met eligibility criteria, representing 28 registered clinical trials and 5 postmarket surveillance studies involving AAV gene therapy for Leber congenital amaurosis (LCA), choroideremia, Leber hereditary optic neuropathy (LHON), age-related macular degeneration (AMD), retinitis pigmentosa (RP), X-linked retinoschisis, and achromatopsia. Overall, AAV therapy vectors were associated with a cumulative incidence of at least one SAE of 8% (95% confidence intervals [CIs] of 5% to 12%). SAEs were often associated with the surgical procedure rather than the therapeutic vector itself. Poor or inconsistent reporting of adverse events (AEs) were a limitation for the meta-analysis. The proportion of patients with any improvement in BCVA and visual sensitivity was 41% (95% CIs of 31% to 51%) and 51% (95% CIs of 31% to 70%), respectively. Systemic immune involvement was associated with a cumulative incidence of 31% (95% CI = 21% to 42%).
CONCLUSIONS
AAV gene therapy vectors appear to be safe but the surgical procedure required to deliver them is associated with some risk. The large variability in efficacy can be attributed to the small number of patients treated, the heterogeneity of the population and the variability in dosage, volume, and follow-up.
TRANSLATIONAL RELEVANCE
This systematic review will help to inform and guide future clinical trials.
Topics: Humans; Retinal Degeneration; Dependovirus; Macular Degeneration; Retinitis Pigmentosa; Genetic Therapy
PubMed: 37982768
DOI: 10.1167/tvst.12.11.24 -
Genetics in Medicine : Official Journal... Mar 2022This study aimed to systematically review and summarize gene therapy treatment for monogenic retinal and optic nerve diseases. (Review)
Review
PURPOSE
This study aimed to systematically review and summarize gene therapy treatment for monogenic retinal and optic nerve diseases.
METHODS
This review was prospectively registered (CRD42021229812). A comprehensive literature search was performed in Ovid MEDLINE, Ovid Embase, Cochrane Central, and clinical trial registries (February 2021). Clinical studies describing DNA-based gene therapy treatments for monogenic posterior ocular diseases were eligible for inclusion. Risk of bias evaluation was performed. Data synthesis was undertaken applying Synthesis Without Meta-analysis guidelines.
RESULTS
This study identified 47 full-text publications, 50 conference abstracts, and 54 clinical trial registry entries describing DNA-based ocular gene therapy treatments for 16 different genetic variants. Study summaries and visual representations of safety and efficacy outcomes are presented for 20 unique full-text publications in RPE65-mediated retinal dystrophies, choroideremia, Leber hereditary optic neuropathy, rod-cone dystrophy, achromatopsia, and X-linked retinoschisis. The most common adverse events were related to lid/ocular surface/cornea abnormalities in subretinal gene therapy trials and anterior uveitis in intravitreal gene therapy trials.
CONCLUSION
There is a high degree of variability in ocular monogenic gene therapy trials with respect to study design, statistical methodology, and reporting of safety and efficacy outcomes. This review improves the accessibility and transparency in interpreting gene therapy trials to date.
Topics: Color Vision Defects; Genetic Therapy; Humans; Optic Nerve Diseases; Retina; Retinal Dystrophies
PubMed: 34906485
DOI: 10.1016/j.gim.2021.10.013 -
Indian Journal of Ophthalmology Mar 2023The extended use of ethambutol beyond 2 months for treating tuberculosis has increased risk of optic neuropathy. We performed a systematic review of studies evaluating... (Review)
Review
The extended use of ethambutol beyond 2 months for treating tuberculosis has increased risk of optic neuropathy. We performed a systematic review of studies evaluating optic neuropathy in extended ethambutol use since 2010 and compared the outcome with a similar systematic review (1965-2010) by Ezer et al. Literature search was conducted in PubMed, Medline, EMBASE, and Cochrane databases. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Main outcome measures were visual acuity, color vision, visual field defects, optical coherence tomography (OCT), and visual evoked potential (VEP). The JBI Critical Appraisal Checklists were used for quality assessment. Twelve studies were selected (out of 639 studies) for analysis of ethambutol optic neuropathy. Visual acuity improvement after stopping ethambutol was statistically significant. Similar improvement was not noted for other outcome measures. On comparing the results of this review with those by Ezer et al., significant improvement was noted in visual acuity, color vision, and visual field defects. Moreover, more patients reported increased optic nerve toxicity, color vision defects, and visual field defects in the present review. Hence, we conclude that the extended use of ethambutol beyond 2 months results in significant optic nerve toxicity. Further randomized controlled trials with different populations are needed to understand the magnitude of this issue.
Topics: Humans; Ethambutol; Evoked Potentials, Visual; Optic Nerve Diseases; Optic Nerve; Checklist; Rare Diseases
PubMed: 36872667
DOI: 10.4103/ijo.IJO_1920_22