Description
Researchers have used AAV-based vectors in pre-clinical research and in clinical trials in which AAV-based vectors have demonstrated a good safety profile. AAVs have also demonstrated lasting therapeutic gene expression following a single treatment in preclinical and clinical studies.Scientists today have used the AAV9 variant, or serotype, of vector in potential product candidates in hemophilia B and Huntington's disease. Research suggests that a greater portion of patients can be effectively treated with AAV9 gene therapy, compared to other AAV-based gene therapies.AAV9 gene therapies present a favorable immunogenicity profile. To date, insect-cell manufactured AAV9 gene therapies have been administered to 22 patients across three clinical studies by a leading gene therapy company without any evidence of AAV9 capsid-specific cellular immune responses or long-term safety complications. One of the major challenges in AAV-based gene therapy is the presence of circulating anti-AAV neutralizing antibodies, which can pre-exist in patients and may prevent successful gene transfer. High levels of circulating anti-AAV neutralizing antibodies can develop after a single administration of gene therapy and can prevent successful gene transfer in patients