Occlusive retinal vasculitis associated with intravitreal Faricimab injections.

PURPOSE: We describe a case of occlusive vasculitis associated with intravitreal Faricimab (Vabysmo) injections. METHODS: A retrospective case report. RESULTS: A 52-year old man treated with monthly Faricimab injections for diabetic macula oedema presented with sudden reduced vision, new retinal hemorrhages, significant retinal vascular occlusions and ischemia. After screening for differential diagnoses was unremarkable, the patient was treated with oral and intravitreal steroid therapy under which the occlusive vasculitis was stabilized. CONCLUSION: Occlusive vasculitis, though rare, is a potential complication of Faricimab therapy. Comprehensive reporting and large-scale analyses are essential to better understand and manage this adverse event.

Peripapillary retinal nerve fibre layer thinning in patients with X-linked retinoschisis.

AIMS: To assess peripapillary retinal nerve fibre layer (pRNFL) thickness in patients with X-linked retinoschisis (XLRS), as pRNFL thinning may limit functional improvements in gene therapy trials. METHODS: This retrospective multicentre study included 49 eyes from 25 patients diagnosed with XLRS. Data collected with multimodal imaging at baseline and last follow-up (when available) included age, best-recorded visual acuity (BRVA), central retinal thickness, macular volume (MV), presence and location of peripheral retinoschisis and pRNFL thickness in the global (G), superotemporal (TS), superonasal (NS), inferotemporal (TI), inferonasal (NI), nasal (N) and temporal (T) sectors. Retinal sensitivity, assessed by microperimetry, was also recorded for seven patients at baseline. RESULTS: pRNFL was thinner (below the fifth percentile) in at least one sector in 72% of right eyes and 79% of left eyes, with thinning across three or more sectors in 20% of right and 17% of left eyes. In 44% of cases, thinning occurred in the temporal sectors of both eyes, with no nasal sectoral thinning. Number of peripheral retinoschisis quadrants matched thinned pRNFL sectors. A strong positive correlation was found between MV and temporal pRNFL thickness (r=0.71, p<0.01), while weak negative correlation trends were noted with age (p=0.05) and BRVA (logMAR; p=0.12) related to temporal thickness of pRNFL sectors. CONCLUSION: pRNFL thinning, predominantly sectoral and linked to macular or peripheral retinoschisis, occurs in about three-quarters of patients with XLRS, while diffuse thinning occurs in one-fifth. Temporal pRNFL thinning might occur only after the collapse of intraretinal cystoid cavities in the macula.

Spontaneous grip force fluctuations mirror semantic numerical magnitude processing: Larger numbers elicit larger forces.

This study investigated the relationship between semantic numerical magnitudes and motor magnitudes. We asked whether the processing of numbers can affect motor behavior such as the size of numbers affecting the size of motor actions. For this, we recorded continuous grip force fluctuations from 43 healthy adults during a symbolic magnitude comparison task. We found that numbers induced spontaneous grip force fluctuations during number processing. Smaller numbers induced lower grip forces, whereas larger numbers induced larger forces. This result constitutes strong behavioral support for a generalized magnitude processing by continuously quantifying the response that challenges binary accounts of cross-domain interactions.

Classification of Cannabis Strains Based on their Chemical Fingerprint-A Broad Analysis of Chemovars in the German Market.

Introduction: Cannabis cultivars were usually categorized based on their genetic profile as sativa, indica, or hybrid types. However, these three criteria do not allow sufficient differentiation between the numerous varieties of cannabis strains. Furthermore, this classification is based on morphological and bio-geographical properties of the plants and does not represent the chemical composition of different cultivars. The concentration of cannabinoids and terpenes are crucial for the pharmacological effect, not only because of the known entourage effect, and therefore needs to be considered by categorization. Materials and Methods: A total of 140 medicinal cannabis flowers available on the German market were analyzed regarding their individual terpene profile using GC-MS analysis. Statistical evaluation was performed to investigate correlations and data relations as well as for clustering. Results: Multivariate analysis showed correlations between individual terpenes. However, there was no statistical correlation between terpene profiles and their respective genetic profile. Terpene profiles of sativa, indica, and hybrid strains are quite heterogenous and clearly showed that there is no relation between terpenes and the estimated pharmacological effect. As a result, we suggest a new classification system based on individual terpene profiles to faster a comprehensive understanding of the expected medical effect. Discussion: Considering main terpenes, we established a concept of six clusters with various terpene profiles being attributed to different medicinal applications. We excluded tetrahydrocannabinol (THC) and cannabidiol (CBD) content from clustering as most of the strains were THC dominant and therefore distort the results. Our pattern of strains with similar terpene profiles might refine the existing classes of chemotypes with different THC:CBD content. Conclusion: The categorization of cannabis strains based on their terpene profiles allows a clearer, finer and, above all, more meaningful classification than the existing sativa/indica classification. Due to the entourage effect and the interactions between cannabinoids and terpenes, this group of substances is also given the necessary consideration when selecting the right medicine for the individual. Within the next steps, further studies are needed with the aim of mapping clinical validated effects to our chemovars. If it is possible to correlate therapy of symptoms to specific chemical profiles personalized cannabinoid therapy will be possible.

An Open-Label Phase II Study Assessing the Safety of Bilateral, Sequential Administration of Retinal Gene Therapy in Participants with Choroideremia: The GEMINI Study.

Choroideremia, an incurable, progressive retinal degeneration primarily affecting young men, leads to sight loss. GEMINI was a multicenter, open-label, prospective, two-period, interventional Phase II study assessing the safety of bilateral sequential administration of timrepigene emparvovec, a gene therapy, in adult males with genetically confirmed choroideremia (NCT03507686, ClinicalTrials.gov). Timrepigene emparvovec is an adeno-associated virus serotype 2 vector encoding the cDNA of Rab escort protein 1, augmented by a downstream woodchuck hepatitis virus post-transcriptional regulatory element. Up to 0.1 mL of timrepigene emparvovec, containing 1 × 1011 vector genomes, was administered by subretinal injection following vitrectomy and retinal detachment. The second eye was treated after an intrasurgery window of <6, 6-12, or >12 months. Each eye was followed at up to nine visits over 12 months. Overall, 66 participants received timrepigene emparvovec, and 53 completed the study. Visual acuity (VA) was generally maintained in both eyes, independent of intrasurgery window duration, even after bilateral retinal detachment and subretinal injection. Bilateral treatment was well tolerated, with predominantly mild or moderate treatment-emergent adverse events (TEAEs) and a low rate of serious surgical complications (7.6%). Retinal inflammation TEAEs were reported in 45.5% of participants, with similar rates in both eyes; post hoc analyses found that these were not associated with clinically significant vision loss at month 12 versus baseline. Two participants (3.0%) reported serious noninfective retinitis. Prior timrepigene emparvovec exposure did not increase the risk of serious TEAEs or serious ocular TEAEs upon injection of the second eye; furthermore, no systemic immune reaction or inoculation effect was observed. Presence of antivector neutralizing antibodies at baseline was potentially associated with a higher percentage of TEAEs related to ocular inflammation or reduced VA after injection of the first eye. The GEMINI study results may inform decisions regarding bilateral sequential administration of other gene therapies for retinal diseases.

Magnon interactions in a moderately correlated Mott insulator.

Quantum fluctuations in low-dimensional systems and near quantum phase transitions have significant influences on material properties. Yet, it is difficult to experimentally gauge the strength and importance of quantum fluctuations. Here we provide a resonant inelastic x-ray scattering study of magnon excitations in Mott insulating cuprates. From the thin film of SrCuO2, single- and bi-magnon dispersions are derived. Using an effective Heisenberg Hamiltonian generated from the Hubbard model, we show that the single-magnon dispersion is only described satisfactorily when including significant quantum corrections stemming from magnon-magnon interactions. Comparative results on La2CuO4 indicate that quantum fluctuations are much stronger in SrCuO2 suggesting closer proximity to a magnetic quantum critical point. Monte Carlo calculations reveal that other magnetic orders may compete with the antiferromagnetic Néel order as the ground state. Our results indicate that SrCuO2-due to strong quantum fluctuations-is a unique starting point for the exploration of novel magnetic ground states.

Dose-Dependent Progression of Chorioretinal Atrophy at the Injection Site After Subretinal Injection of rAAV2/8 in Nonhuman Primates.

Objective: Progressive retinal atrophy has been described after subretinal gene therapy utilizing the adeno-associated virus (AAV) vector platform. To elucidate whether this atrophy is a consequence of inherent properties of AAV, or if it is related to the surgical trauma of subretinal delivery, we analyzed data from an Investigational New Drug-enabling study for PDE6A gene therapy in nonhuman primates. Design: Animal study (nonhuman primates), retrospective data analysis. Subjects: Forty eyes of 30 healthy nonhuman primates (macaca fascicularis) were included in the analysis. Two AAV dose levels (low: 1x10E11, high: 1x10E12) were compared with sham injection (balanced saline solution; BSS). Twenty untreated eyes were not analyzed. Methods: Animals were treated with a sutureless 23G vitrectomy and single subretinal injections of AAV.PDE6A and/or BSS. The follow-up period was 12 weeks. Atrophy development was followed using fundus autofluorescence (AF), OCT, fluorescence angiography, and indocyanine green angiography. Main Outcome Measures: Area [mm2] of retinal pigment epithelium atrophy on AF. Presence of outer retinal atrophy on optical coherence tomography. Area [mm2] of hyperfluorescence in fluorescence angiography and hypofluorescence in indocyanine green angiography. Results: Progressive atrophy at the injection site developed in 54% of high-dose-treated, 27% of low-dose-treated, and 0% of sham-treated eyes. At the end of observation, the mean ± SD area of atrophy in AF was 1.19 ± 1.75 mm2, 0.25 ± 0.50 mm2, and 0.0 ± 0.0 mm2, respectively (sham × high dose: P = 0.01). Atrophic lesions in AF (P = 0.01) and fluorescence angiography (P = 0.02) were significantly larger in high-dose-treated eyes, compared with sham-treated eyes. Rate of progression in high-dose-treated eyes was 4.1× higher compared with low-dose-treated eyes. Conclusion: Subretinal injection of AAV.PDE6A induced dose-dependent, progressive retinal atrophy at the site of injection. Findings from multimodal imaging were in line with focal, transient inflammation within the retina and choroid and secondary atrophy. Atrophic changes after gene therapy with AAV-based vector systems are not primarily due to surgical trauma and increase with the dose given. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Early REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion (REVISION): Study protocol of a phase III trial.

RATIONALE: Meta-analyses of case series of non-arteritic central retinal artery occlusion (CRAO) indicate beneficial effects of intravenous thrombolysis when initiated early after symptom onset. Randomized data are lacking to address this question. AIMS: The REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion (REVISION) investigates intravenous alteplase within 4.5 h of monocular vision loss due to acute CRAO. METHODS: This study is the randomized (1:1), double-blind, placebo-controlled, multicenter adaptive phase III trial. STUDY OUTCOMES: Primary outcome is functional recovery to normal or mildly impaired vision in the affected eye defined as best-corrected visual acuity of the Logarithm of the Minimum Angle of Resolution of 0.5 or less at 30 days (intention-to-treat analysis). Secondary efficacy outcomes include modified Rankin Score at 90 days and quality of life. Safety outcomes include symptomatic intracranial hemorrhage, major bleeding (International Society on Thrombosis and Haemostasis definition) and mortality. Exploratory analyses of optical coherence tomography/angiography, ultrasound and magnetic resonance imaging (MRI) biomarkers will be conducted. SAMPLE SIZE: Using an adaptive design with interim analysis at 120 patients, up to 422 participants (211 per arm) would be needed for 80% power (one-sided alpha = 0.025) to detect a difference of 15%, assuming functional recovery rates of 10% in the placebo arm and 25% in the alteplase arm. DISCUSSION: By enrolling patients within 4.5 h of CRAO onset, REVISION uses insights from meta-analyses of CRAO case series and randomized thrombolysis trials in acute ischemic stroke. Increased rates of early reperfusion and good neurological outcomes in stroke may translate to CRAO with its similar pathophysiology. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04965038; EU Trial Number: 2023-507388-21-00.

Retention Rates of Genetic Therapies Based on AAV Serotypes 2 and 8 Using Different Drug-Delivery Materials.

The purpose of this study was to compare the retention rate of Adeno-associated viral vector (AAV) gene therapy agents within different subretinal injection systems. The retention of AAV serotype 2-based voretigene neparvovec (VN) and a clinical-grade AAV serotype 8 vector within four different subretinal cannulas from two different manufacturers was quantified. A standardized qPCR using the universal inverted terminal repeats as a target sequence was developed. The instruments compared were the PolyTip® cannula 25 g/38 g by MedOne Surgical, Inc., Sarasota, FL, USA, and three different subretinal injection needles by DORC, Zuidland, The Netherlands (1270.EXT Extendible 41G subretinal injection needle (23G), DORC 1270.06 23G Dual bore injection cannula, DORC 27G Subretinal injection cannula). The retention rate of VN and within the DORC products (10-28%) was comparable to the retention rate (32%) found for the PolyTip® cannula that is mentioned in the FDA-approved prescribing information for VN. For the AAV8 vector, the PolyTip® cannula showed a retention rate of 14%, and a similar retention rate of 3-16% was found for the DORC products (test-retest variability: mean 4.5%, range 2.5-20.2%). As all the instruments tested showed comparable retention rates, they seem to be equally compatible with AAV2- and AAV8-based gene therapy agents.

Improvements of complex post-traumatic stress disorder symptoms during a multimodal psychodynamic inpatient rehabilitation treatment - results of an observational single-centre pilot study.

Background: Complex post-traumatic stress disorder (CPTSD) describes chronic disturbances in self-organization (i.e. affect dysregulation; negative self-concept; severe difficulties in relationships) which are frequently observed in survivors of prolonged, repeated or multiple traumatic stressors. So far, evidence of psychodynamic treatment approaches for CPTSD is scarce.Methods: In this single-centre observational pilot study, symptom change during a 6-week psychodynamic inpatient treatment in a multimodal psychosomatic rehabilitation centre was evaluated using repeated measures analyses of variance (ANOVAs). Patients completed questionnaires on PTSD and CPTSD symptoms (ITQ), anxiety, depression and somatization (BSI-18), functional impairment (WHODAS) and epistemic trust, mistrust and credulity (ETMCQ) before (T1) and at the end of treatment (T2). A hierarchical linear regression analysis was calculated to identify factors associated with improved CPTSD symptoms.Results: A total of n = 50 patients with CPTSD were included in the study, of whom n = 40 (80%) completed treatment. Patients reported a significant reduction of CPTSD symptoms during treatment with a large effect size (-3.9 points; p < .001; η2 = .36), as well as a significant reduction of psychological distress (p < .001; η2 = .55) and functional impairment (p < .001; η2 = .59). At the end of treatment, 41.0% of patients no longer fulfilled the diagnostic criteria for CPTSD. Changes in epistemic stance included improved epistemic trust (ß = -.34, p = .026) and decreased epistemic credulity (ß = .37, p = .017), which together with lower age (ß = .43, p = .012) and lower depression levels at baseline (ß = .35, p = .054) were significantly associated with baseline adjusted mean change of CPTSD symptoms during therapy and explained 48% of its variance.Discussion: In our study, patients reported a significant reduction of CPTSD symptoms and comorbid symptoms during a multimodal psychodynamic inpatient rehabilitation treatment. Improved epistemic trust may facilitate the establishment of a trusting therapeutic relationship, thus fostering an environment of openness for knowledge transfer (i.e. social learning) and the exploration of diverse viewpoints and perspectives in the therapeutic process.

Complex post-traumatic stress disorder (CPTSD) is a condition often found in individuals who have experienced severe trauma, such as childhood abuse or torture.A study involving 50 patients with CPTSD showed significant improvements in symptoms and overall quality of life after undergoing a 6-week integrative multimodal psychodynamic inpatient rehabilitation treatment.The study also highlighted that improvement in epistemic trust could be a potential mechanism of change contributing to the positive therapeutic outcomes.

An analytical strategy for challenging members of the microplastic family: Particles from anti-corrosion coatings.

Potentially hazardous particles from paints and functional coatings are an overlooked fraction of microplastic (MP) pollution since their accurate identification and quantification in environmental samples remains difficult. We have applied the most relevant techniques from the field of microplastic analysis for their suitability to chemically characterize anti-corrosion coatings containing a variety of polymer binders (LDIR, Raman and FTIR spectroscopy, Py-GC/MS) and inorganic additives (ICP-MS/MS). We present the basis of a possible toolbox to study the release and fate of coating particles in the (marine) environment. Our results indicate that, due to material properties, spectroscopic methods alone appear to be unsuitable for quantification of coating/paint particles and underestimate their environmental abundance. ICP-MS/MS and an optimized Py-GC/MS approach in combination with multivariate statistics enables a straightforward comparison of the multi-elemental and organic additive fingerprints of paint particles. The approach can improve the identification of unknown particles in environmental samples by an assignment to different typically used coating types. In future, this approach may facilitate allocation of emission sources of different environmental paint/coating particles. Indeed, future work will be required to tackle various remaining analytical challenges, such as optimized particle extraction/separation of environmental coating particles.

A Prospective, Observational, Non-interventional Clinical Study of Participants With Choroideremia: The NIGHT Study.

PURPOSE: The NIGHT study aimed to assess the natural history of choroideremia (CHM), an X-linked inherited chorioretinal degenerative disease leading to blindness, and determine which outcomes would be the most sensitive for monitoring disease progression. DESIGN: A prospective, observational, multicenter cohort study. METHODS: Males aged ≥18 years with genetically confirmed CHM, visible active disease within the macular region, and best-corrected visual acuity (BCVA) ≥34 Early Treatment Diabetic Retinopathy Study (ETDRS) letters at baseline were assessed for 20 months. The primary outcome was the change in BCVA over time at Months 4, 8, 12, 16, and 20. A range of functional and anatomical secondary outcome measures were assessed up to Month 12, including retinal sensitivity, central ellipsoid zone (EZ) area, and total area of fundus autofluorescence (FAF). Additional ocular assessments for safety were performed. RESULTS: A total of 220 participants completed the study. The mean BCVA was stable over 20 months. Most participants (81.4% in the worse eye and 77.8% in the better eye) had change from baseline > -5 ETDRS letters at Month 20. Interocular symmetry was low overall. Reductions from baseline to Month 12 were observed (worse eye, better eye) for retinal sensitivity (functional outcome; -0.68 dB, -0.48 dB), central EZ area (anatomical outcome; -0.276 mm2, -0.290 mm2), and total area of FAF (anatomical outcome; -0.605 mm2, -0.533 mm2). No assessment-related serious adverse events occurred. CONCLUSIONS: Retinal sensitivity, central EZ area, and total area of FAF are more sensitive than BCVA in measuring the natural progression of CHM.

Real-World Safety and Effectiveness of Voretigene Neparvovec: Results up to 2 Years from the Prospective, Registry-Based PERCEIVE Study.

Voretigene neparvovec (VN) is the first available gene therapy for patients with biallelic RPE65-mediated inherited retinal dystrophy who have sufficient viable retinal cells. PERCEIVE is an ongoing, post-authorization, prospective, multicenter, registry-based observational study and is the largest study assessing the real-world, long-term safety and effectiveness of VN. Here, we present the outcomes of 103 patients treated with VN according to local prescribing information. The mean (SD) age was 19.5 (10.85) years, 52 (50.5%) were female, and the mean (SD) duration of the follow up was 0.8 (0.64) years (maximum: 2.3 years). Thirty-five patients (34%) experienced ocular treatment-emergent adverse events (TEAEs), most frequently related to chorioretinal atrophy (n = 13 [12.6%]). Eighteen patients (17.5%; 24 eyes [13.1%]) experienced ocular TEAEs of special interest, including intraocular inflammation and/or infection related to the procedure (n = 7). The mean (SD) changes from baseline in full-field light-sensitivity threshold testing (white light) at month 1, month 6, year 1, and year 2 were -16.59 (13.48) dB (51 eyes), -18.24 (14.62) dB (42 eyes), -15.84 (14.10) dB (10 eyes), and -13.67 (22.62) dB (13 eyes), respectively. The change in visual acuity from baseline was not clinically significant. Overall, the outcomes of the PERCEIVE study are consistent with the findings of VN pivotal clinical trials.

Outcomes and Adverse Effects of Voretigene Neparvovec Treatment for Biallelic RPE65-Mediated Inherited Retinal Dystrophies in a Cohort of Patients from a Single Center.

Our study evaluated the morphological and functional outcomes, and the side effects, of voretigene neparvovec (VN) gene therapy for RPE65-mediated inherited retinal dystrophies (IRDs) in 12 eyes (six patients) at the Oxford Eye Hospital with a mean follow-up duration of 8.2 (range 1-12) months. All patients reported a subjective vision improvement 1 month after gene therapy. Best-corrected visual acuity (BCVA) remained stable (baseline: 1.28 (±0.71) vs. last follow-up: 1.46 (±0.60); p = 0.25). Average white Full-Field Stimulus Testing (FST) showed a trend towards improvement (baseline: -4.41 (±10.62) dB vs. last follow-up: -11.98 (±13.83) dB; p = 0.18). No changes in central retinal thickness or macular volume were observed. The side effects included mild intraocular inflammation (two eyes) and cataracts (four eyes). Retinal atrophy occurred in 10 eyes (eight mild, two severe) but did not impact FST measurements during the follow-up period. Increased intraocular pressure (IOP) was noted in three patients (six eyes); four eyes (two patients) required glaucoma surgery. The overall safety and effectiveness of VN treatment in our cohort align with previous VN clinical trials, except for the higher occurrence of retinal atrophy and increased IOP in our cohort. This suggests that raised IOP and retinal atrophy may be more common than previously reported.

Weight loss induced alleviation of sleep-disordered breathing is associated with improvement of non-alcoholic fatty liver disease.

INTRODUCTION: Sleep-disordered breathing (SDB) and non-alcoholic fatty liver disease (NAFLD) are both common comorbidities in obese patients. Structured weight loss programs are effective and can reduce the incidence and severity of obesity-related comorbidities. The objective of the present analysis is to test whether weight loss induced alleviation of SDB is a predictor for improvement of NAFLD. METHODS: Obese participants underwent a standardized non-surgical 3 months weight reduction program (800 kilocalories per day with low carbohydrate and fat content). Abdominal sonography for NAFLD (grade 0 to 3) and monitoring for SDB (defined as apnea-hypopnea index [AHI] ≥ 15/h) were performed at baseline and after 3 months. Alleviation of SDB was defined as a shift from AHI≥ 15/h to <15/h. RESULTS: 48 patients (48% female, age 42 ± 12 years, body-mass index 40.3 ± 8.1 kg/m2, AHI 14 ± 17/h, 85% NAFLD grade ≥1) participated in the weight loss program. In contrast to the no SDB group, in patients with SDB weight loss of 27.1 ±0 .9 kg (8.4 ± 2.8 kg/m2) after three months was paralleled by a reduction in AHI (-22 ± 17/h), prevalence of SDB (from 31% to 13%), and oxidized low-density lipoprotein (-13 ± 11 U/l). In individuals with preexisting SDB NAFLD grade improved more (2 versus 1, p<0.001) and was at a lower degree at 3 months than in those without SDB (0 versus 1, p = 0.015). In multivariable analysis models, SDB at baseline was associated with improvement of NAFLD grade (B 0.908; 95% CI 0.125, 1.691; p = 0.024), independently of age, sex, and BMI (each p>0.05, respectively). Decreasing BMI (B 0.16 [95%-CI 0.08; 0.23], p<0.001) and alleviation of SDB (B 0.90 [95%-CI 0.21; 1.58], p = 0.012) were independently associated with improvement of NAFLD grade. CONCLUSION: Preexisting SDB and weight loss induced alleviation of SDB are predictors for improvement in NAFLD grade, independent of the extent of weight loss. SDB may contribute to the pathogenesis of NAFLD via SDB-induced oxidative stress and inflammation, but the causal mechanism remains unclear.

Subretinal timrepigene emparvovec in adult men with choroideremia: a randomized phase 3 trial.

Choroideremia is a rare, X-linked retinal degeneration resulting in progressive vision loss. A randomized, masked, phase 3 clinical trial evaluated the safety and efficacy over 12 months of follow-up in adult males with choroideremia randomized to receive a high-dose (1.0 × 1011 vector genomes (vg); n = 69) or low-dose (1.0 × 1010 vg; n = 34) subretinal injection of the AAV2-vector-based gene therapy timrepigene emparvovec versus non-treated control (n = 66). Most treatment-emergent adverse events were mild or moderate. The trial did not meet its primary endpoint of best-corrected visual acuity (BCVA) improvement. In the primary endpoint analysis, three of 65 participants (5%) in the high-dose group, one of 34 (3%) participants in the low-dose group and zero of 62 (0%) participants in the control group had ≥15-letter Early Treatment Diabetic Retinopathy Study (ETDRS) improvement from baseline BCVA at 12 months (high dose, P = 0.245 versus control; low dose, P = 0.354 versus control). As the primary endpoint was not met, key secondary endpoints were not tested for significance. In a key secondary endpoint, nine of 65 (14%), six of 35 (18%) and one of 62 (2%) participants in the high-dose, low-dose and control groups, respectively, experienced ≥10-letter ETDRS improvement from baseline BCVA at 12 months. Potential opportunities to enhance future gene therapy studies for choroideremia include optimization of entry criteria (more preserved retinal area), surgical techniques and clinical endpoints. EudraCT registration: 2015-003958-41 .

Choroideremia: The Endpoint Endgame.

Choroideremia is an X-linked retinal degeneration resulting from the progressive, centripetal loss of photoreceptors and choriocapillaris, secondary to the degeneration of the retinal pigment epithelium. Affected individuals present in late childhood or early teenage years with nyctalopia and progressive peripheral visual loss. Typically, by the fourth decade, the macula and fovea also degenerate, resulting in advanced sight loss. Currently, there are no approved treatments for this condition. Gene therapy offers the most promising therapeutic modality for halting or regressing functional loss. The aims of the current review are to highlight the lessons learnt from clinical trials in choroideremia, review endpoints, and propose a future strategy for clinical trials.