Argenx and Unnatural Products ink US$1.5bn macrocycle deal

Under the terms of the agreement, UNP will receive upfront, near-term payments and R&D funding. UNP is also eligible to receive up to approximately US$1.5bn in potential research, development, regulatory, and commercial milestones and option payments, as well as tiered royalties on net sales. Additionally, argenx will make an equity investment in UNP.

The collaboration will utilize UNP’s proprietary drug discovery platform to generate potent, selective, and orally available macrocyclic peptides against multiple targets of interest identified by argenx that were undruggable with either small molecules as well as biologics.. Under the terms of the agreement, UNP will conduct research and development until IND-enabling studies, and argenx will have the exclusive option to develop and commercialise products against these targets across multiple indications.

According to UNP, macrocyclic peptides represent a new frontier in drug development, offering the precision of biologics with the convenience of small molecule oral dosing and the ability to reach previously inaccessible intracellular protein targets. UNP has built a scalable platform to engineer synthetic macrocycles using AI-guided design, parallel synthesis, and direct-to-biology screening.

“Macrocyclic peptides are opening up a new modality, one that merges the best attributes of biologics and small molecules to drug targets that were once considered out of reach,” said Cameron Pye, Ph.D., CEO and Co-Founder, Unnatural Products. “argenx has built a world-class engine for immunology innovation, and we’re thrilled to partner with them to advance novel macrocyclic peptide therapeutics for patients with immune disorders.”

UNP’s platform enables the rapid generation of drug-like macrocycles that bind challenging targets with antibody-like specificity. UNP is building a pipeline of oral medicines for oncology, immunology and rare diseases.

In January 2024, UNP already penned an US$220m biobucks deal with Merck & Co, known as MSD in Europe, which hailed macrocycles as the “next wave of drug discovery”. However, competition exists. Emerging company ThirdLaw Molecular Inc presented an alternative dubbed Spiroligomers with similar attributes as macrocyles at SLAS Europe 2025 in Hamburg.