Lilly's $1.3B Bet on RNA Editing for Hearing Loss: A New Frontier in Gene Therapy

Eli Lilly has made a significant move in the hearing loss treatment landscape, announcing a partnership worth up to $1.3 billion with South Korean biotech Rznomics. This collaboration aims to leverage Rznomics' proprietary ribozyme technology to develop RNA editing therapies for congenital hearing loss, marking a new chapter in Lilly's ongoing efforts to address this prevalent condition.

The Rznomics Partnership: A Strategic Investment in RNA Editing

Lilly's deal with Rznomics, announced on May 16, 2025, centers on the biotech's trans-splicing ribozyme technology. This innovative approach utilizes RNA molecules with enzymatic activity to target disease-specific RNA and splice in therapeutic payloads. While the exact upfront payment and number of candidates remain undisclosed, the partnership structure involves Rznomics leading early-stage studies before Lilly takes charge of further development and commercialization.

The collaboration's focus on heritable sensorineural hearing loss aligns with Lilly's existing pursuits in this therapeutic area. Rznomics stands to benefit not only from the substantial contract payments and milestones but also from separate royalties on any resulting products.

Lilly's Expanding Hearing Loss Pipeline

This latest partnership complements Lilly's ongoing efforts in hearing loss treatment. In January 2024, the company reported promising results from its gene therapy candidate AK-OTOF, which successfully restored hearing in an 11-year-old boy within 30 days of treatment. AK-OTOF, acquired through Lilly's $487 million purchase of Akouos in October 2022, uses an adeno-associated virus vector to deliver a functional copy of the otoferlin gene to inner ear hair cells.

The addition of Rznomics' RNA editing technology to Lilly's arsenal potentially expands the company's approach to addressing congenital hearing loss, offering a multi-pronged strategy in this competitive field.

The Race for Hearing Loss Gene Therapies

Lilly's aggressive moves in the hearing loss space reflect a broader industry trend. Regeneron, another major player, is advancing its own gene therapy called DB-OTO. Like Lilly's AK-OTOF, DB-OTO aims to restore hearing in children with congenital hearing loss by delivering a functional otoferlin gene.

Recent data from Regeneron has shown promising results, with DB-OTO restoring normal hearing within 24 weeks of infusion in some patients. In February 2025, the company reported that DB-OTO had restored at least partial hearing in 10 out of 12 treated children with profound hearing loss associated with otoferlin dysfunction.

As these therapies progress through clinical development, the potential for transformative treatments in congenital hearing loss becomes increasingly tangible, promising hope for millions affected by this condition worldwide.