Eli Lilly has entered a global research and licensing collaboration with Ascidian Therapeutics centered on RNA exon editing for monogenic inherited kidney diseases. Under the reported structure, Lilly will pay up to $1.9 billion across upfront and milestone payments plus royalties, with Ascidian leading discovery and early preclinical work while Lilly takes responsibility for later preclinical, clinical, manufacturing, and commercialization. Ascidian’s approach is described as rewriting disease-causing exons at the RNA level using endogenous splicing machinery, with delivery envisioned through adeno-associated virus expressing the designed RNA exon editor. The company also retains freedom to pursue other targets outside the collaboration. For RNA medicines, the deal is notable for tying a large, late-stage-capable pharma partner to a cargo approach aimed at addressing large genes or multiple-exon mutation landscapes that are difficult for conventional editing tools.