International expert consensus on gene therapy for hereditary hearing loss: Based on clinical trials

Background: Hereditary hearing loss is one of the most common disabling disorders in children and lacks effective pharmacological treatments. Recent breakthroughs in OTOF gene therapy clinical trials necessitate standardized frameworks to guide emerging therapies. This study aims to establish the first international consensus on the clinical application of gene therapy for hereditary hearing loss. Methods: A modified Delphi process was conducted from March 2024 to March 2025, involving 46 multidisciplinary experts from several countries across otology, genetics, audiology, gene therapy, and hearing rehabilitation. After a systematic literature review, as well as integration of research and clinical expertise and experience, three iterative voting rounds (two anonymous surveys and one online consensus meeting) were performed. Statements required ≥75% agreement for inclusion. Findings: From 9,093 publications, 69 were used to draft and support the consensus statements. A total of 30 statements relevant to six domains achieved consensus on gene therapy for hereditary hearing loss, including ethical review (1 statement), patient selection criteria (12 statements), diagnosis and preoperative evaluation (9 statements), gene therapy drug delivery (4 statements), follow-up (3 statements), and post-treatment auditory and speech rehabilitation (1 statement). Conclusions: This consensus provides the first globally endorsed framework for gene therapy in hereditary hearing loss. It standardizes clinical trial design and patient management, accelerating translation from research to practice while ensuring safety. The guidelines are immediately applicable to OTOF-related hearing loss and adaptable to other genetic forms. Funding: This work was supported by the National Natural Science Foundation of China, the German Research Foundation (DFG) via the Cluster of Excellence, and others.