argenx agreed on 9 November 2026 to acquire Unnatural Products, a privately held Santa Cruz, California, developer of oral macrocyclic peptides, for US$550m upfront and up to US$595m in milestone payments, a total potential value of about US$1.15bn.
Why argenx SE is buying Unnatural Products, Inc.
argenx said UNP's platform, which combines AI-guided design, massively parallel synthesis and direct-to-biology screening, would add oral and long-acting options to its antibody-based immunology pipeline and open previously hard-to-drug targets. Chief executive Karen Massey said: "UNP adds macrocyclic peptide capabilities that are highly complementary to our antibody engineering". UNP's Santa Cruz site will become argenx's peptide discovery hub, with UNP leading discovery and argenx handling clinical development and commercialisation.
Deal terms and financing
argenx, already a minority shareholder, will buy all remaining shares for US$550m upfront from cash on hand, plus up to US$595m tied to specified development and regulatory milestones. The boards of both companies have approved the deal.
Regulatory approvals and timing
Closing is expected by the end of 2026, subject to customary closing conditions.
Market context
The two companies signed a multi-target research collaboration in July 2025 that included an equity investment by argenx and was valued at up to about US$1.5bn in milestones. UNP, founded in 2016 by Cameron Pye and Joshua Schwochert, also has partnerships with Novartis, Merck and BridgeBio.
