Stargardt disease:monitoring incidence and diagnostic trends in the Netherlands using a nationwide disease registry

PURPOSE: To assess the incidence of Stargardt disease (STGD1) and to evaluate demographics of incident cases. METHODS: For this retrospective cohort study, demographic, clinical and genetic data of patients with a clinical diagnosis of STGD1 were registered between September 2010 and January 2020 in a nationwide disease registry. Annual incidence (2014-2018) and point prevalence (2018) were assessed on the basis of this registry. RESULTS: A total of 800 patients were registered, 56% were female and 83% were of European ancestry. The incidence was 1.67-1.95:1,000,000 per year and the point prevalence in 2018 was approximately 1:22,000-1:19,000 (with and without 10% of potentially unregistered cases). Age at onset was associated with sex (p = 0.027, Fisher's exact); 1.9x more women than men were observed (140 versus 74) amongst patients with an age at onset between 10 and 19 years, while the sex ratio in other age-at-onset categories approximated one. Late-onset STGD1 (≥45 years) constituted 33% of the diagnoses in 2014-2018 compared to 19% in 2004-2008. Diagnostic delay (≥2 years between the first documentation of macular abnormalities and diagnosis) was associated with older age of onset (p = 0.001, Mann-Whitney). Misdiagnosis for age-related macular degeneration (22%) and incidental STGD1 findings (14%) was common in patients with late-onset STGD1. CONCLUSION: The observed prevalence of STGD1 in real-world data was lower than expected on the basis of population ABCA4 allele frequencies. Late-onset STGD1 was more frequently diagnosed in recent years, likely due to higher awareness of its phenotype. In this pretherapeutic era, mis- and underdiagnosis of especially late-onset STGD1 and the role of sex in STGD1 should receive special attention

Designing a clinical trial to evaluate the safety and efficacy of oral soraprazan in Stargardt Disease

Purpose: To date there are no treatments available for Stargardt disease (STGD). The investigational drug soraprazan has demonstrated (in pre-clinical studies) the ability to remove lipofuscin, one of the hallmarks in STGD pathogenesis, from Retinal Pigment Epithelium (RPE) cells. Soraprazan was originally designed to treat gastro-esophageal reflux disease and successfully completed phase I and phase II clinical trials, where safety and tolerability was already demonstrated. The aim is to start a phase II trial to evaluate the efficacy of soraprazan in reducing the amount of lipofuscin in RPE cells of subjects with STGD.Methods: An international consortium was formed consisting of 5 investigator sites (2 in Netherlands and 1 in each of Germany, UK, and Italy), a Contract Research Organisation, and a start-up company as a sponsor (Katairo). A draft protocol and a business plan were fully costed and timeline

The STArgardt Remofuscin Treatment Trial (STARTT): Design and baseline characteristics of enrolled Stargardt patients

Background: This report describes the study design and baseline characteristics of patients with Stargardt disease (STGD1) enrolled in the STArgardt Remofuscin Treatment Trial (STARTT). Methods: In total, 87 patients with genetically confirmed STGD1 were randomized in a double-masked, placebo-controlled proof of concept trial to evaluate the safety and efficacy of 20 milligram oral remofuscin for 24 months. The primary outcome measure is change in mean quantitative autofluorescence value of an 8-segment ring centred on the fovea (qAF 8). Secondary efficacy variables are best corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), mesopic microperimetry (mMP), spectral domain optical coherence tomography (SD-OCT), reading speed on Radner reading charts, and patient-reported visual function as assessed by the National Eye Institute Visual Functioning Questionnaire 25 (NEI VFQ-25) and Functional Reading Independence (FRI) Index. Results: Mean age of participants was 35±11 years with 49 (56%) female. Median qAF 8 value was 438 Units (range 210-729). Median BCVA and LLVA in decimal units were 0.50 (range 0.13-0.80) and 0.20 (range 0.06-0.63), respectively. The median of the mean retinal sensitivity with mMP was 20.4 dB (range 0.0-28.8). SD-OCT showed median central subfield retinal thickness of 142 m (range 72-265) and median macular volume of 1.65 mm 3 (range 1.13-2.19). Compared to persons without vision impairment, both reading performance and patient-reported visual function were significantly lower (p<0.001, one sample t-test). Mean reading speed was 108±39 words/minute with logRAD-score of 0.45±0.28. Mean VFQ-25 composite score was 72±13. Mean FRI Index score 2.8±0.6. Conclusions: This trial design may serve as reference for future clinical trials as it explores the utility of qAF 8 as primary outcome measure. The baseline data represent the largest, multi-national, STGD1 cohort to date that underwent standardized qAF imaging, reading speed assessment and vision-related quality of life measures which all contribute to the characterization of STGD1