argenx Agrees to Buy Unnatural Products for $550 Million Upfront and Up to $1.15 Billion to Add Macrocyclic Peptides
argenx will pay $550 million in cash upfront and up to $595 million in development and regulatory milestones for Santa Cruz, California-based Unnatural Products, whose discovery engine designs macrocyclic peptides, small ring-shaped chains of amino acids that can be built to bind disease targets. argenx said in its November 9 announcement that the peptides could support oral or long-acting medicines for immune-mediated diseases alongside its antibody work; the deal is expected to close by the end of 2026.