argenx stock lifts BEL 20 as peptide deal enters focus

Published on 11/09/2026 at 17:49 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

argenx stock drew attention as the BEL 20 moved into record territory after the Unnatural Products deal. Closing is expected by year-end.

Peptide deal reshapes market focus

argenx agreed to acquire Unnatural Products, adding a macrocyclic peptide discovery platform to its immunology pipeline.
The BEL 20 moved into record territory at midday, with argenx identified as its strongest positive influence.
The transaction is expected to close by year-end, subject to customary conditions.

Argenx, NL0010832176, Illustration mit AI erstellt.

argenx stock was a key positive influence on Brussels trading on Monday, November 9, after argenx announced an agreement to acquire Unnatural Products. The deal adds a macrocyclic peptide discovery platform to the immunology company and helped place the stock at the center of the Belgian market session, according to an ad-hoc-news market report.

Acquisition expands peptide research

argenx already holds a minority stake in Unnatural Products and plans to acquire the remaining shares. The agreement calls for 550 million US dollars in upfront cash and up to 595 million US dollars tied to development and regulatory milestones, bringing the potential consideration to as much as 1.15 billion US dollars.

Unnatural Products develops orally delivered macrocyclic peptides using parallel experimentation and machine learning. The platform is intended to broaden argenx's ability to pursue novel biology and develop oral or long-acting treatments for serious immune-mediated diseases.

Closing remains ahead

The boards of both companies have approved the transaction. Completion is expected by the end of 2026, subject to customary closing conditions. Unnatural Products is expected to continue operating from its Santa Cruz, California site, which will become argenx's peptide discovery hub after completion.

argenx will contribute clinical development and commercialization capabilities, while Unnatural Products will continue its discovery work within an agreed strategic framework. The financial and pipeline impact therefore remains linked to closing and to the achievement of the specified milestones.

Market context and current quote

The BEL 20 stood at 6,059.77 points at midday, up 1.06 percent from Friday's close, and moved above its previous record level. The market report also cited a recovery in several Asian markets and investor focus on the upcoming US inflation data.

argenx stock traded at 855.40 euros on Lang & Schwarz at 17:43 CET on Monday, November 9, 2026.