---
title: "argenx to Buy Unnatural Products for Up to $1.15 Billion"
url: https://www.herestpetersburg.com/2026/11/09/argenx-buy-unnatural-products-1-15-billion/
date: 2026-11-09T06:16:06-05:00
modified: 2026-11-09T06:16:06-05:00
author: "Merger Monday"
categories: ["Business", "National"]
site: "HERE St. Petersburg"
attribution: "HERE St. Petersburg"
---

# argenx to Buy Unnatural Products for Up to $1.15 Billion

*Source: [HERE St. Petersburg](https://www.herestpetersburg.com/2026/11/09/argenx-buy-unnatural-products-1-15-billion/) — November 9, 2026 by Merger Monday*

argenx SE agreed to buy Unnatural Products Inc., a Santa Cruz, Calif., biotech that designs macrocyclic peptides, for $550 million in cash upfront and up to $595 million more if its programs reach development and regulatory milestones, putting the potential value of the deal at about $1.15 billion.

The Amsterdam-based immunology company, whose main product is an antibody fragment that blocks the neonatal Fc receptor, already holds a minority stake in UNP and has worked with it on several drug targets for more than two years. argenx will pay the upfront portion from cash on hand. Both boards approved the deal, which is expected to close by year-end.

## Pills instead of infusions

Macrocyclic peptides are ring-shaped molecules that can bind targets with the precision of a biologic but may be taken by mouth or dosed less often, and they can reach proteins inside cells that antibodies cannot. UNP pairs machine-learning-guided design with large-scale parallel synthesis and screening to produce drug-like candidates. argenx said the platform complements its antibody engineering and could lead to oral or long-acting medicines for immune diseases.

UNP’s team, led by co-founder and Chief Executive Cameron Pye, will stay in Santa Cruz, which becomes argenx’s peptide discovery site, and will keep running its discovery work within a framework agreed with the parent. argenx will handle clinical development and commercialization. Morgan Stanley advised argenx, with DLA Piper as legal counsel; Latham & Watkins advised UNP.

The milestone-heavy structure lets argenx limit upfront spending on an early-stage platform while it shifts its pipeline beyond a single blockbuster franchise. More than half of the headline value depends on progress that has yet to happen.