Ascidian Secures Up to $1.9 Billion in Lilly Kidney Disease Partnership

Eli Lilly and Ascidian Therapeutics have entered a global research collaboration and licensing agreement to discover and develop RNA‑based therapies for undisclosed monogenic kidney diseases. The partnership gives Lilly exclusive rights to apply Ascidian’s RNA exon editing technology to selected kidney disease targets, expanding its genetic medicine portfolio with a novel RNA‑based therapeutic approach. Ascidian retains the freedom to pursue additional kidney disease targets independently or with other partners.

Deal Structure and Strategic Scope

The collaboration carries a potential value of up to $1.9 billion, including an upfront payment, development and commercial milestone payments, and tiered royalties on worldwide sales. Ascidian will lead discovery and selected preclinical activities, while Lilly will assume responsibility for additional preclinical development, clinical studies, manufacturing, and commercialization.

The deal strengthens Lilly’s position in genetic medicine while providing access to a platform that may address mutations beyond the reach of conventional gene therapy and gene‑editing technologies. The $1.9 billion figure is contingent on milestones, with the size of the upfront payment undisclosed.

Differentiation in RNA Therapeutics

Ascidian’s RNA exon editing platform operates at the transcript level, using the cell’s natural RNA splicing machinery to replace or repair entire exons spanning several kilobases. This enables correction of mutations across large or highly variable genes, areas that remain challenging for existing genetic medicine platforms.

Unlike DNA‑editing and gene replacement approaches, RNA exon editing does not permanently modify the genome or require foreign enzymes, offering potential durable benefit while avoiding risks tied to irreversible genetic modification. The platform complements other RNA‑based approaches, including ADAR‑mediated editing and antisense oligonucleotides, by enabling broader correction of complex genetic defects.

Regulatory and Competitive Context

RNA exon editing remains an emerging modality, with regulatory pathways expected to align more closely with RNA‑based medicines than DNA‑editing programs. The collaboration reflects growing industry interest in RNA‑based strategies that preserve genomic integrity. For Lilly, the agreement builds on its broader expansion in genetic medicines through recent acquisitions and collaborations, positioning the company to address inherited diseases historically beyond the reach of gene therapy.

Addressing Unmet Need in Kidney Disease

More than 60 known genetic disorders affect the kidneys, with severe inherited conditions impacting an estimated 3.5 million people in the United States. Many of these diseases stem from mutations in large or variable genes that have proven difficult to address with existing technologies. Patients often face progressive kidney dysfunction and limited treatment options beyond supportive care, dialysis, or transplantation. By targeting these difficult‑to‑treat mutations, Lilly and Ascidian aim to advance new therapeutic options for inherited kidney disorders with substantial unmet medical need.

Clinical Implications and Path Forward

Michael Ehlers, M.D., Ph.D., President and Chief Executive Officer of Ascidian Therapeutics, said RNA exon editing has the potential to address inherited kidney diseases underserved by current genetic medicine approaches. He noted that combining Ascidian’s platform with Lilly’s development and commercialization capabilities could accelerate progress toward new treatment options. Initial efforts will focus on target discovery and preclinical validation, with specific disease targets and timelines yet to be disclosed.

Reference

Ascidian-Lilly-Partnership_Final-PR_03-June-2026.pdf