Current Management of Patients with RPE65 Mutation Associated Inherited Retinal Degenerations in Europe: Results of a 2-Year Follow-Up Multinational Survey

Introduction: To evaluate the current management of RPE65-biallelic mutation-associated inherited retinal degeneration (RPE65-IRD) in Europe since market authorization of Voretigene Neparvovec (VN, LuxturnaTM) in 2018. By July 2022, over 200 patients have been treated outside the USA, of whom about 90% in Europe. We conducted among all centers of the European Vision Institute Clinical Research Network (EVICR.net) and health care providers (HCPs) of the European Reference Network dedicated to Rare Eye Diseases (ERN-Eye) the second multinational survey on management of IRDs in Europe elaborated by EVICR.net with a special focus on RPE65-IRD.Methods: An electronic survey questionnaire with 48 questions specifically addressing RPE65-IRD (2019 survey 35) was developed and sent by June 2021 to 95 EVICR.net centers and 40 ERN-EYE HCPs and affiliated members. Of note, 11 centers are members of both networks. Statistical analysis was performed with Excel and R.Results: The overall response rate was 44% (55/124); 26 centers follow RPE65 biallelic mutation-associated IRD patients. By June 2021, 8/26 centers have treated 57 RPE65-IRD cases (1 - 19/center, median 6), and 43 planned for treatment (range 0 - 10/center, median 6). The overall age range was 3 - 52 years, and on average 22% of the patients did not (yet) qualify for treatment (range 2 - 60%/center, median 15%). Main reasons were too advanced (range 0-100, median 75%) or mild disease (range 0-100, median 0). Eighty-three percent of centers (10/12) that follow RPE65 mutation-associated IRD patients treated with VN participate in the PERCEIVE registry (EUPAS31153, http://www.encepp.eu/encepp/viewResource.htm?id=37005). Quality of life and full field stimulus test (FST) improvements had the highest scores of the survey-reported outcome parameters in VN treatment follow-up. Discussion/Conclusion: This second multinational survey on management of RPE65-IRD by EVICR.net centers and ERN-Eye HCPs in Europe indicates that RPE65-IRD might be diagnosed more reliably in 2021 compared to 2019. By June 2021, 8/26 centers reported detailed results including VN treatment. Main reasons for non-treatment were too advanced or mild disease, followed by absence of two class 4 or 5 mutations on both alleles, or because of a too young age. Patient satisfaction with treatment was estimated to be high by 50% of the centers.