Viral-based gene therapy clinical trials for immune deficiencies and blood disorders from 2013 until 2023 - an overview.

Gene therapy (GT) as a groundbreaking approach holds promise for treating many diseases including immune deficiencies and blood disorders. GT can benefit patients suffering from these diseases, especially those without matched donors or who are at risk after hematopoietic stem cell transplantation (HSCT). Due to all the advances in the field of GT, its main challenge is still gene delivery. Generally, gene delivery systems are categorized into two types depending on utilized vectors: non-viral and viral. Viral vectors are commonly used in GT because of their high efficiency compared to non-viral vectors. In this article, all clinical trials on viral-based GT (with the exclusion of CRISPR and CAR-T cell Therapy) in the last decade for immune deficiencies and blood disorders including Severe combined immune deficiency (SCID), Wiskott-Aldrich syndrome (WAS), Chronic granulomatous disease (CGD), Leukocyte adhesion deficiency (LAD), Fanconi anemia (FA), Hemoglobinopathies, and Hemophilia will thoroughly be discussed. Moreover, viral vectors used in these trials including Retroviruses (RVs), Lentiviruses (LVs), and Adeno-Associated Viruses (AAVs) will be reviewed. This review provides a concise overview of traditional treatments for the mentioned disease and precise details of their viral-based GT clinical trial studies in the last decade, then presents the advantages, disadvantages, and potential adverse events of GT. In conclusion, this review presents GT as a hopeful and growing field in healthcare that could offer cures to diseases that were previously thought to be untreatable.