Argenx Inks $1.5B Deal with UNP for Macrocyclic Peptides Targeting 'Undruggable' Diseases

Argenx, a leading biotechnology company, has entered into a significant partnership with Unnatural Products, Inc. (UNP) to develop oral macrocyclic peptides for multiple disease targets previously considered "undruggable." The collaboration, valued at up to $1.5 billion, marks a major step forward in the pursuit of novel therapeutic modalities that combine the benefits of both biologics and small molecule drugs.

Deal Structure and Financial Terms

The agreement between Argenx and UNP involves a substantial upfront payment described as "double-digit million-dollar," although the exact figure was not disclosed. UNP stands to receive up to $1.5 billion in future research, development, regulatory, and commercial milestones, as well as option commitments. Additionally, UNP will be eligible for tiered royalties on net sales of products resulting from the collaboration.

Argenx has also committed to participating in UNP's upcoming Series B funding round, further solidifying the partnership. This deal is reported to be the largest licensing agreement to date in the macrocyclic peptide space, underscoring its significance in the pharmaceutical industry.

Technology and Development Strategy

At the core of this collaboration is UNP's proprietary AI-driven drug discovery platform, which generates synthetic peptides mimicking macrocycles. These molecules are designed to engage complex targets like biologics while maintaining the ability to pass through cell membranes similar to small molecule drugs.

Under the terms of the agreement, UNP will utilize its macrocyclic peptide technology to discover orally available drug candidates for multiple targets selected by Argenx. UNP will be responsible for early-stage development up to IND-enabling studies, after which Argenx will have the option to advance the candidates into clinical trials.

Strategic Implications for Argenx

This partnership represents a strategic move for Argenx to diversify its pipeline and reduce dependence on its flagship product, efgartigimod (marketed as Vyvgart and Vyvgart Hytrulo). The Vyvgart franchise, which brought in $2.2 billion in 2024, is protected by patents until at least 2033. However, the collaboration with UNP allows Argenx to explore new therapeutic avenues and potentially address a broader range of diseases.

Argenx's current pipeline includes the complement blocker empasiprubart for various indications and ARGX-119, a MuSK-targeting candidate for amyotrophic lateral sclerosis and congenital myasthenic syndrome. The addition of UNP's macrocyclic peptide technology could significantly expand Argenx's capabilities in targeting previously unreachable disease pathways.