argenx stock targets oral therapies with peptide acquisition

argenx announced on Monday, November 9, 2026, that it had agreed to acquire Unnatural Products, a privately held biotechnology company focused on macrocyclic peptide discovery. The company said in a press release carried by BioSpace that it already owns a minority stake in Unnatural Products and will purchase the remaining shares.

argenx stock traded at 868.40 euros on Lang & Schwarz at 10:08 CET on Wednesday, November 11, 2026.

Transaction adds a new discovery platform

The agreement combines Unnatural Products' peptide expertise with argenx's antibody engineering. argenx said the combination could broaden its ability to pursue novel biology and develop potential oral or long-acting medicines for people with serious immune-mediated diseases.

Unnatural Products uses parallel experimentation and machine learning to address challenges in macrocyclic peptide design. After closing, the company is expected to continue operating from Santa Cruz, California, which will become argenx's peptide discovery center. Unnatural Products' team and leadership are expected to continue leading discovery work within a strategic framework agreed with argenx.

Cash payment and milestones

argenx will pay 550 million US dollars upfront from cash on hand. Up to 595 million US dollars is contingent on specified development and regulatory milestones, bringing the potential total consideration to 1.15 billion US dollars. The milestone payments are not guaranteed and depend on future development and regulatory progress.

The boards of both companies have approved the transaction. Closing is expected by the end of 2026, subject to customary closing conditions. Until completion, the agreement remains subject to transaction risks, including the possibility that the closing does not occur on the expected timetable.

Pipeline ambition remains prospective

argenx Chief Executive Officer Karen Massey said the peptide capabilities are complementary to the company's antibody engineering and could create new possibilities for oral and long-acting medicines. Unnatural Products Chief Executive Officer and co-founder Cameron Pye said the transaction could help accelerate the platform and its development potential.

The announcement gives argenx a broader technology base beyond its established antibody focus, but it does not identify a clinical-stage Unnatural Products candidate or disclose specific development programs. For investors, the strategic opportunity therefore depends on future research, clinical and regulatory execution rather than on an immediate product contribution.

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