CHANGES IN RETINAL SENSITIVITY AFTER GENE THERAPY IN CHOROIDEREMIA.

PURPOSE: Choroideremia (CHM) is a rare inherited retinal degeneration resulting from mutation of the CHM gene, which results in absence of functional Rab escort protein 1 (REP1). We evaluated retinal gene therapy with an adeno-associated virus vector that used to deliver a functional version of the CHM gene (AAV2-REP1). METHODS: THOR (NCT02671539) is a Phase 2, open-label, single-center, randomized study. Six male patients (51-60 years) with CHM received AAV2-REP1, by a single 0.1-mL subretinal injection of 10 genome particles during vitrectomy. Twelve-month data are reported. RESULTS: In study eyes, 4 patients experienced minor changes in best-corrected visual acuity (-4 to +1 Early Treatment Diabetic Retinopathy Study [ETDRS] letters); one gained 17 letters and another lost 14 letters. Control eyes had changes of -2 to +4 letters. In 5/6 patients, improvements in mean (95% confidence intervals) retinal sensitivity (2.3 [4.0] dB), peak retinal sensitivity (2.8 [3.5] dB), and gaze fixation area (-36.1 [66.9] deg) were recorded. Changes in anatomical endpoints were similar between study and control eyes. Adverse events were consistent with the surgical procedure. CONCLUSION: Gene therapy with AAV2-REP1 can maintain, and in some cases, improve, visual acuity in CHM. Longer term follow-up is required to establish whether these benefits are maintained.

Three-year results of phase I retinal gene therapy trial for CNGA3-mutated achromatopsia: results of a non randomised controlled trial.

AIMS: To determine long-term safety and efficacy outcomes of a subretinal gene therapy for CNGA3-associated achromatopsia. We present data from an open-label, nonrandomised controlled trial (NCT02610582). METHODS: Details of the study design have been previously described. Briefly, nine patients were treated in three escalating dose groups with subretinal AAV8.CNGA3 gene therapy between November 2015 and October 2016. After the first year, patients were seen on a yearly basis. Safety assessment constituted the primary endpoint. On a secondary level, multiple functional tests were carried out to determine efficacy of the therapy. RESULTS: No adverse or serious adverse events deemed related to the study drug occurred after year 1. Safety of the therapy, as the primary endpoint of this trial, can, therefore, be confirmed. The functional benefits that were noted in the treated eye at year 1 were persistent throughout the following visits at years 2 and 3. While functional improvement in the treated eye reached statistical significance for some secondary endpoints, for most endpoints, this was not the case when the treated eye was compared with the untreated fellow eye. CONCLUSION: The results demonstrate a very good safety profile of the therapy even at the highest dose administered. The small sample size limits the statistical power of efficacy analyses. However, trial results inform on the most promising design and endpoints for future clinical trials. Such trials have to determine whether treatment of younger patients results in greater functional gains by avoiding amblyopia as a potential limiting factor.

[Transcorneal electrostimulation in retinitis pigmentosa : Protocol of a multicentric prospective, randomized, controlled and double-masked trial on behalf of the Joint Federal Committee (G-BA pilot regulation)]. / Transkorneale Elektrostimulation bei Retinitis pigmentosa : Prüfplan einer multizentrischen, prospektiven, randomisierten, kontrollierten und doppelblinden Studie im Auftrag des Gemeinsamen Bundesausschusses (G-BA-Erprobungsrichtlinie).

The focus of this large multicenter trial commissioned by the Joint Federal Committee (Gemeinsamer Bundesausschuss, G­BA) is to determine a benefit of transcorneal electrical stimulation for retinitis pigmentosa (RP) patients. The main criterion for benefit is the kinetic visual field and whether the deterioration progresses more slowly in the study eyes compared to the sham-stimulated fellow eyes over a treatment period of 3 years.

Safety and Vision Outcomes of Subretinal Gene Therapy Targeting Cone Photoreceptors in Achromatopsia: A Nonrandomized Controlled Trial.

Importance: Achromatopsia linked to variations in the CNGA3 gene is associated with day blindness, poor visual acuity, photophobia, and involuntary eye movements owing to lack of cone photoreceptor function. No treatment is currently available. Objective: To assess safety and vision outcomes of supplemental gene therapy with adeno-associated virus (AAV) encoding CNGA3 (AAV8.CNGA3) in patients with CNGA3-linked achromatopsia. Design, Setting, and Participants: This open-label, exploratory nonrandomized controlled trial tested safety and vision outcomes of gene therapy vector AAV8.CNGA3 administered by subretinal injection at a single center. Nine patients (3 per dose group) with a clinical diagnosis of achromatopsia and confirmed biallelic disease-linked variants in CNGA3 were enrolled between November 5, 2015, and September 22, 2016. Data analysis was performed from June 6, 2017, to March 12, 2018. Intervention: Patients received a single unilateral injection of 1.0 × 1010, 5.0 × 1010, or 1.0 × 1011 total vector genomes of AAV8.CNGA3 and were followed up for a period of 12 months (November 11, 2015, to October 10, 2017). Main Outcomes and Measures: Safety as the primary end point was assessed by clinical examination of ocular inflammation. Systemic safety was assessed by vital signs, routine clinical chemistry testing, and full and differential blood cell counts. Secondary outcomes were change in visual function from baseline in terms of spatial and temporal resolution and chromatic, luminance, and contrast sensitivity throughout a period of 12 months after treatment. Results: Nine patients (mean [SD] age, 39.6 [11.9] years; age range, 24-59 years; 8 [89%] male) were included in the study. Baseline visual acuity letter score (approximate Snellen equivalent) ranged from 34 (20/200) to 49 (20/100), whereas baseline contrast sensitivity log scores ranged from 0.1 to 0.9. All 9 patients underwent surgery and subretinal injection of AAV8.CNGA3 without complications. No substantial safety problems were observed during the 12-month follow-up period. Despite the congenital deprivation of cone photoreceptor-mediated vision in achromatopsia, all 9 treated eyes demonstrated some level of improvement in secondary end points regarding cone function, including mean change in visual acuity of 2.9 letters (95% CI, 1.65-4.13; P = .006, 2-sided t test paired samples). Contrast sensitivity improved by a mean of 0.33 log (95% CI, 0.14-0.51 log; P = .003, 2-sided t test paired samples). Conclusions and Relevance: Subretinal gene therapy with AAV8.CNGA3 was not associated with substantial safety problems and was associated with cone photoreceptor activation in adult patients, as reflected by visual acuity and contrast sensitivity gains. Trial Registration: ClinicalTrials.gov Identifier: NCT02610582.

Efficacy and Safety of Retinal Gene Therapy Using Adeno-Associated Virus Vector for Patients With Choroideremia: A Randomized Clinical Trial.

IMPORTANCE: Choroideremia (CHM) is a rare, degenerative, genetic retinal disorder resulting from mutation of the CHM gene, leading to an absence of functional ras-associated binding escort protein 1 (REP1). There is currently no approved treatment for CHM. OBJECTIVE: To assess the safety and efficacy of retinal gene therapy with an adeno-associated virus vector (AAV2) designed to deliver a functional version of the CHM gene (AAV2-REP1) for treatment of patients with choroideremia. DESIGN, SETTING, AND PARTICIPANTS: Tübingen Choroideremia Gene Therapy (THOR) was a single-center, phase 2, open-label randomized clinical trial. Data were collected from January 11, 2016, to February 26, 2018. Twenty-four-month data are reported for 6 men with a molecularly confirmed diagnosis of CHM. Intention-to-treat analysis was used. INTERVENTIONS: Patients received AAV2-REP1 by a single, 0.1-mL subretinal injection of 1011 genome particles during vitrectomy into 1 eye randomly assigned to receive treatment. MAIN OUTCOMES AND MEASURES: Primary end point was change in best-corrected visual acuity (BCVA) on the Early Treatment Diabetic Retinopathy Study chart from baseline to month 24 in the treated eye vs the control eye. Secondary end points included microperimetry variables, change in fundus autofluorescence, and spectral-domain optical coherence tomographic evaluations from baseline to month 24 in the treated eye vs the control eye. RESULTS: On enrollment, the mean (SD) age of the 6 men included in the study was 54.9 (4.1) years. The mean (SD) BCVA score was 60.3 (13.4) (approximately 20/63 Snellen equivalent) in the study eyes and 69.3 (20.6) (approximately 20/40 Snellen equivalent) in the control eyes. At 24 months, the BCVA change was 3.7 (7.5) in the treated eyes and 0.0 (5.1) in the control eyes (difference, 3.7; 95% CI, -7.2 to 14.5; P = .43). Mean change in retinal sensitivity was 10.3 (5.5) dB in the treated eyes and 9.7 (4.9) dB in the control eyes (difference, 0.6; 95% CI, -10.2 to 11.4; P = .74). A total of 28 adverse events were reported; all were consistent with the surgical procedure (eg, conjunctival hyperemia, foreign body sensation), and none were regarded as severe. CONCLUSIONS AND RELEVANCE: Among 6 participants, gene therapy with AAV2-REP1 was associated with maintenance or improvement of visual acuity, although no significant difference was found from control eyes. All safety issues were associated with the surgical procedure and none were judged severe. Continued investigations could more precisely define the efficacy and safety of gene therapy with AAV2-REP1 in CHM. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02671539.

Development of Methodology and Study Protocol: Safety and Efficacy of a Single Subretinal Injection of rAAV.hCNGA3 in Patients with CNGA3-Linked Achromatopsia Investigated in an Exploratory Dose-Escalation Trial.

Achromatopsia is an autosomal recessively inherited congenital defect characterized by a lack of cone photoreceptor function, leading to severely impaired vision. In this clinical study, achromatopsia patients were treated with a single subretinal injection of rAAV.hCNGA3 to restore cone function. The focus of this trial was on the safety of the treatment. After surgery, patients were monitored in eight extensive visits during the first year, followed by a 4-year follow-up period with annual visits. For essential complementation of the standard ophthalmological and systemic examinations, disease-specific methods were developed to assess the safety, efficacy, and patient-reported outcomes in this trial.

Tasting Pseudomonas aeruginosa Biofilms: Human Neutrophils Express the Bitter Receptor T2R38 as Sensor for the Quorum Sensing Molecule N-(3-Oxododecanoyl)-l-Homoserine Lactone.

Bacteria communicate with one another via specialized signaling molecules, known as quorum sensing molecules or autoinducers. The Pseudomonas aeruginosa-derived quorum sensing molecule N-(3-oxododecanoyl)-l-homoserine lactone (AHL-12), however, also activates mammalian cells. As shown previously, AHL-12-induced chemotaxis, up-regulated CD11b expression, and enhanced phagocytosis of polymorphonuclear neutrophils. Circumstantial evidence concurred with a receptor for AHL-12, which has been elusive so far. We now investigated the bitter receptor T2R38 as a potential candidate. Although identified as a taste receptor, extragustatory cells express T2R38, for example, epithelial cells in the lung. We now detected T2R38 in peripheral blood neutrophils, monocytes, and lymphocytes. T2R38 is not only found on the cell membrane but also intracellular. In neutrophils, T2R38 was located in vesicles with characteristics of lipid droplets, and super-resolution microscopy showed a co-localization with the lipid droplet membrane. Neutrophils take up AHL-12, and it co-localized with T2R38 as seen by laser scan microscopy. Binding of AHL-12 to T2R28 was confirmed by pull-down assays using biotin-coupled AHL-12 as bait. A commercially available antibody to T2R38 inhibited binding of AHL-12 to neutrophils, and this antibody by itself stimulated neutrophils, similarly to AHL-12. In conclusion, our data provide evidence for expression of functional T2R38 on neutrophils, and are compatible with the notion that T2R38 is the receptor for AHL-12.

Galectin-3 inhibits the chemotaxis of human polymorphonuclear neutrophils in vitro.

In the recent years, the participation of the animal lectin galectin (gal)-3 in inflammation and in host defence mechanisms was extensively studied. In vivo studies implied - among others - a role of gal-3 in the recruitment of polymorphonuclear neutrophils (PMN) to sites of bacterial infection. In that context, we asked the question whether gal-3 was chemotactic for PMN. Functional assays revealed that gal-3 was not chemotactic for PMN, but that it inhibited the spontaneous migration and the chemotaxis of PMN towards complement C5a, interleukin (IL)-8, or ATP. Moreover, gal-3 inhibited the shape change and the actin polymerisation of PMN that occurs in response to C5a or IL-8. By use of FITC-labelled gal-3, we found that it attached rapidly to the PMN membrane in a lactose-sensitive manner. In response to gal-3 the MAP kinase p38 was phosphorylated. This kinase is crucial for the migration of PMN towards end-target chemokines, such as C5a, and is activated in response to C5a or IL-8. When PMN were preincubated with gal-3, the C5a-induced p38 phosphorylation was transiently enhanced, but eventually down-modulated. We conclude that by interfering with the chemokine-induced p38 phosphorylation gal-3 inhibits chemotaxis of PMN.