By Mariam Sunny and Bhanvi Satija

Jan 28 (Reuters) - U.S. drugmaker Eli Lilly LLY.N signed an agreement worth up to $1.12 billion with Seamless Therapeutics, the Germany-based startup said on Wednesday, to develop and commercialize treatments for hearing loss using the biotech's gene-editing platform.

The deal will give Lilly access to its proprietary technology to design specially engineered enzymes to correct certain gene mutations linked to hearing loss.

These enzymes, called programmable recombinases, are designed to make large, precise changes to DNA at specific locations without relying on the cell's own DNA repair pathway.

Lilly would oversee the development from preclinical testing through to commercialization.

The deal is a "way for us to work with the platform, with a partner, but continue our own internal program," Seamless CEO Albert Seymour told Reuters in an interview. He said the company is open to similar partnerships beyond Lilly.

The company has raised over $40 million, Seymour said, adding that including Lilly's upfront payment, it was well funded to advance its first experimental drug to lab studies by the end of the year.

Lilly's $1.12 billion offer includes an upfront payment, funding for research and development, as well as future payments upon completing certain development and commercial milestones.

The drugmaker has been steadily building a pipeline of genetic medicines for multiple diseases, through acquisitions and partnerships, as it looks beyond its blockbuster weight-loss and diabetes drugs Zepbound and Mounjaro for growth.

Lilly shelled out $1.3 billion last year to buy Verve Therapeutics and develop gene-editing therapies to reduce high cholesterol in people with heart disease.

It also acquired Akouos in 2022 in a $487 million buyout to get access to its gene-therapy candidate for hearing loss. The therapy showed hearing restoration in children in an early to mid-stage trial in 2024.

(Reporting by Mariam Sunny in Bengaluru and Bhanvi Satija in London; Editing by Shinjini Ganguli)

((Mariam.ESunny@thomsonreuters.com;))