Eli Lilly entered a global research and licensing collaboration with Ascidian Therapeutics for RNA exon editing therapeutics targeting monogenic kidney diseases. The deal could reach up to $1.9 billion in upfront, development, regulatory, and commercial milestones plus royalties, with Lilly holding exclusive rights to Ascidian’s platform for agreed targets. Ascidian’s “RNA exon editors” are designed to rewrite disease-causing exons at the RNA level by using endogenous splicing machinery, in contrast to permanent DNA editing. The therapy is delivered via AAV expressing the exon editor, aiming to replace multiple damaged exons where mutations span large genomic regions. The companies will start by focusing on undisclosed inherited kidney disease targets, with an option for Lilly to expand into additional targets over time. Ascidian retains the freedom to pursue other kidney programs through separate collaborations or independently. For Lilly, the agreement extends its genetic medicine strategy beyond CRISPR-style editing into RNA-level repair designed to fit delivery constraints in kidney indications.