Skylark Bio Doses First Patient in SONIX Phase 1/2 Trial of SKY-GJB2 for GJB2-Related Pediatric Deafness

SONIX trial advances development of potential one-time treatment for children with GJB2-related hearing loss, the most common genetic cause of pediatric deafness

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Skylark Bio, a clinical-stage biotechnology company developing targeted genetic medicines for hearing loss and other monogenic disorders, today announced that the first patient has been dosed in the SONIX Phase 1/2 clinical trial evaluating SKY-GJB2, the Company’s investigational inner-ear-targeted gene therapy for GJB2-mediated hearing loss.

“Dosing the first patient in SONIX brings us one step closer to a future where children born with genetic hearing loss have new treatment options that could meaningfully change the trajectory of their lives. SONIX is designed to generate preliminary data by year-end 2026 with additional readouts anticipated in 2027. The recent approval of a targeted inner-ear AAV-delivered therapy provides important validation for the field and further reinforces our confidence in this approach,” said Jodi Cook, PhD, Chief Executive Officer of Skylark Bio. “We are honored by the trust of participating families and grateful to the investigators and site teams supporting this study.”

Skylark Bio is advancing a differentiated genetic medicine platform designed for monogenic diseases where no approved therapies exist and where precise local delivery and disease-relevant, cell-specific expression are critical to success.

“Launching the SONIX trial marks an exciting milestone for children and families affected by GJB2-related hearing loss,” said Daniel Lee, MD, FACS, Ansin Foundation Chair in Otolaryngology at Massachusetts Eye and Ear and Scientific Advisor to Skylark Bio. “Although current interventions provide meaningful benefits, they do not address the underlying genetic cause. We look forward to evaluating SKY-GJB2 and its potential to support more natural hearing and spoken-language development.”

About the SONIX Trial

The SONIX trial is a multicenter, open-label Phase 1/2 study designed to assess the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of a single unilateral intracochlear injection of SKY-GJB2 in children aged 9 months to 7 years. Preliminary data will be available at year-end 2026 with additional readouts anticipated in 2027. Additional information about the SONIX study is available at www.sonixstudy.com and ClinicalTrials.gov.

About SKY-GJB2 and GJB2-Related Hearing Loss

GJB2‑related hearing loss is the most common genetic cause of nonsyndromic deafness and one of the most prevalent and tractable monogenic forms of hearing disorders. There are currently no approved disease‑modifying treatments. Genetic changes in GJB2 disrupt the function of connexin 26, a protein essential to the gap-junction network of the inner ear and maintenance of normal hearing function.

Current treatment options, including hearing aids and cochlear implants, can provide partial access to sound but do not restore natural hearing or address the underlying biology. Outcomes vary widely, particularly among young children. SKY-GJB2 is designed as a potential first-in-class therapy to address the underlying cause of GJB2-related hearing loss by precisely delivering a functional copy of GJB2 to supporting cells in the cochlea that naturally express connexin 26, with the goal of restoring the gap-junction network essential for hearing.

About Skylark Bio

Skylark Bio is a clinical-stage genetic medicine company developing precision, locally delivered gene therapies for monogenic diseases, with the potential to meaningfully improve patient outcomes and quality of life. The company’s lead program, SKY-GJB2, is being evaluated in SONIX, a Phase 1/2 clinical trial for GJB2-related hearing loss, the leading cause of inherited hearing loss worldwide. Additional programs include SKY-PEN for SLC26A4-related hearing loss and an undisclosed program in CNS.

Skylark’s proprietary gene therapy platform is built on an engineered capsid designed for broad transduction, with targeted microdose delivery, cell-specific expression control, and durable benefit. Led by a team with deep expertise in gene therapy and supported by world-class advisors, Skylark is advancing a pipeline of innovative therapies for hearing loss and other genetic disorders that profoundly impact patients and families.

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