Argenx to buy Unnatural Products in deal worth up to $1.15 billion

Argenx said on Monday it will acquire Unnatural Products for $550 million upfront plus up to $595 million in milestone payments, valuing the Santa Cruz peptide biotech at up to about $1.15 billion.

Why it matters: The deal gives argenx, already a minority holder in Unnatural Products, full control of its macrocyclic peptide discovery platform after a two-year research collaboration, extending its immunology pipeline toward orally delivered drugs for targets previously seen as undruggable.

Data as of argenx press release of November 9, 2026 (07:00 CET, Amsterdam), issued via GlobeNewswire and read in full in this run; every figure comes from the release itself. The Investing.com item that first surfaced the deal could not be opened directly, so the release was obtained as the second route under the blocked-item rule. Developing item.

Argenx said on Monday it has agreed to acquire Unnatural Products, Inc., the Santa Cruz, California biotech developing orally delivered macrocyclic peptides, for an upfront payment of $550 million in cash on hand plus up to $595 million contingent on development and regulatory milestones, for total potential consideration of up to about $1.15 billion. Argenx already holds a minority stake in the company and will acquire all remaining shares; both boards have approved the transaction, which is expected to close by the end of the year subject to customary closing conditions.

The acquisition builds on a two-year multi-target research collaboration between the companies, and Unnatural Products’ team and platform will continue in Santa Cruz as argenx’s dedicated macrocyclic peptide discovery hub. Morgan Stanley is acting as exclusive financial advisor to argenx, with DLA Piper as legal advisor and Latham & Watkins advising Unnatural Products.

Argenx to buy Unnatural Products in deal worth up to $1.15 billion

Sources