biostudies-literatureUnknown14Kruzik ABaxalta US Inc.Baxalta Innovations GmbHPreexisting immunity against adeno-associated virus (AAV) is a major challenge facing AAV gene therapy, resulting in the exclusion of patients from clinical trials. Accordingly, proper assessment of anti-AAV immunity is necessary for understanding clinical data and for product development. Previous studies on anti-AAV prevalence lack method standardization, rendering the assessment of prevalence difficult. Addressing this need, we used clinical assays that were validated according to guidelines for a comprehensive characterization of anti-AAV1, -AAV2, -AAV5, and -AAV8 immunity in large international cohorts of healthy donors and patients with hemophilia B. Here, we report a higher than expected average prevalence for anti-AAV8 (∼40%) and anti-AAV5 (∼30%) neutralizing antibodies (NAbs), whiMolecular therapy. Methods & clinical development126-133https://www.ebi.ac.uk/biostudies/studies/S-EPMC6629972biostudies-literaturePrevalence of Anti-Adeno-Associated Virus Immune Responses in International Cohorts of Healthy Donors.PMC6629972de la Rosa MKruzik AFetahagic DDorn SHorling FMHartlieb BScheiflinger FKoppensteiner HReipert BMfalsePrevalence of Anti-Adeno-Associated Virus Immune Responses in International Cohorts of Healthy Donors.Preexisting immunity against adeno-associated virus (AAV) is a major challenge facing AAV gene therapy, resulting in the exclusion of patients from clinical trials. Accordingly, proper assessment of anti-AAV immunity is necessary for understanding clinical data and for product development. Previous studies on anti-AAV prevalence lack method standardization, rendering the assessment of prevalence difficult. Addressing this need, we used clinical assays that were validated according to guidelines for a comprehensive characterization of anti-AAV1, -AAV2, -AAV5, and -AAV8 immunity in large international cohorts of healthy donors and patients with hemophilia B. Here, we report a higher than expected average prevalence for anti-AAV8 (∼40%) and anti-AAV5 (∼30%) neutralizing antibodies (NAbs), whi2019-01-01T00:00:00Z2019 Sep2026-05-07T01:05:23.41Z2019-07-30T07:06:29ZS-EPMC66299723133838410.1016/j.omtm.2019.05.014