Skylark Bio opens trial for GJB2-linked deafness as biotech race to target distinct genetic causes intensifies

Skylark Bio, a biotechnology company, has commenced a gene therapy clinical trial for hereditary deafness caused by mutations in GJB2, the gene encoding connexin 26. Loss-of-function variants in GJB2 represent one of the most prevalent monogenic causes of congenital, non-syndromic hearing loss in many populations.

According to reporting by STAT News, Skylark Bio's programme is one of several now in early clinical development, with companies in the United States, France, and China each pursuing distinct molecular targets. A separately funded programme targeting otoferlin (encoded by OTOF), the protein whose absence disrupts synaptic transmission in inner hair cells, has previously attracted attention; Skylark's GJB2-focused approach addresses a different and broader genetic population.

Gene therapies for deafness present particular delivery challenges: the inner ear is anatomically accessible but requires highly localised administration, typically by intracochlear injection, to reach the hair cells and supporting cells that express connexin 26. Preclinical data for connexin-targeting approaches have shown restoration of gap-junction function in animal models, though translation to human hearing outcomes remains to be established in the new trial.

The broader competitive landscape underscores a shift in rare-disease gene therapy towards conditions defined by well-characterised single-gene variants with clearly delineated biology. The trial's full design, including primary endpoints, dosing, and eligibility criteria, had not been published in full at the time of reporting.