argenx to Acquire UNP, Adding a New Molecular Discovery Platform

argenx announced a definitive agreement to acquire Unnatural Products, Inc. (UNP), a biotechnology company focused on macrocyclic peptide discovery. The transaction represents a strategic expansion of argenx’s drug discovery capabilities, adding a new molecular platform alongside its established antibody engineering expertise.

The acquisition is intended to expand the range of biological targets the company can investigate and create opportunities to develop medicines with the potential for oral administration or longer-lasting effects. These capabilities could support argenx’s efforts to address serious immune-mediated diseases through additional therapeutic approaches.

Building on More Than Two Years of Collaboration

The agreement follows more than two years of collaboration and investment between the companies. argenx already holds a minority stake in UNP and will acquire all of the company’s remaining shares under the definitive agreement.

UNP was founded by Cameron Pye, Ph.D., and Joshua Schwochert, Ph.D., following their doctoral research in Professor Scott Lokey’s laboratory at the University of California, Santa Cruz. Their academic work provided the scientific foundation for the company’s focus on macrocyclic peptide discovery.

Argenx Chief Executive Officer Karen Massey described UNP’s macrocyclic peptide capabilities as highly complementary to the company’s antibody engineering platform. She highlighted the potential to explore additional treatment approaches while emphasizing the importance of preserving UNP’s science-first and entrepreneurial culture.

Cameron Pye, Ph.D., CEO and Co-Founder of UNP, described the agreement as a significant milestone for the company. He said argenx would provide an environment to accelerate the development of UNP’s discovery platform and advance its vision of developing innovative medicines.

Following completion of the acquisition, UNP’s existing team and leadership will continue operating from its site in Santa Cruz, California, which will become argenx’s dedicated peptide discovery hub. UNP will lead its discovery activities within a strategic framework agreed upon with argenx, while argenx will contribute its clinical development and commercialization capabilities to advance potential medicines.

Macrocyclic Peptides Expand the Drug Discovery Approach

Macrocyclic peptides are molecules composed of amino acids arranged in ring-like structures. Their molecular characteristics offer another approach to investigating biological targets and developing potential therapeutic candidates.

However, designing macrocyclic peptides for therapeutic applications presents considerable medicinal chemistry challenges. UNP has developed a discovery platform that combines parallel experimentation with machine learning to address these complexities.

The company is developing a portfolio of therapeutic macrocycles directed at high-value targets that have traditionally been difficult to drug.

For argenx, the acquisition introduces a distinct molecular format into its discovery capabilities. Antibody engineering and macrocyclic peptide discovery offer different approaches to exploring biological targets. Combining these capabilities could broaden the company’s research options and support investigations into disease biology that may be challenging to address through its existing approaches alone.

The potential to develop oral or longer-lasting medicines is another important aspect of the acquisition. However, these represent future development possibilities rather than established clinical benefits of UNP’s platform.

Transaction Terms and Expected Completion

Under the agreement, argenx will pay $550 million upfront using cash on hand. UNP may receive up to an additional $595 million through payments contingent on achieving specified development and regulatory milestones, bringing the total potential transaction value to approximately $1.15 billion.

The milestone-based structure links a substantial portion of the acquisition consideration to future development and regulatory progress. Consequently, the maximum transaction value does not represent the upfront cost of acquiring UNP.

The boards of directors of both companies have approved the agreement. The acquisition is expected to close by year-end 2026, subject to customary closing conditions.

Expanding Future Treatment Possibilities

The acquisition does not mean that new treatments are immediately available for patients or that UNP’s discovery programmes have demonstrated clinical efficacy. Instead, it strengthens argenx’s ability to investigate additional therapeutic approaches by combining peptide discovery with antibody engineering and established clinical development capabilities.

The potential development of oral and long-acting medicines could eventually offer alternative treatment formats for people living with immune-mediated diseases. However, candidates emerging from the platform will require appropriate preclinical and clinical evaluation to establish their safety and effectiveness.

Strategically, the acquisition marks an expansion of argenx’s discovery model beyond antibody engineering. Whether this broader molecular toolkit translates into differentiated clinical candidates will depend on the company’s ability to advance UNP’s discovery programmes through subsequent development and regulatory stages.

Reference

argenx to Acquire Unnatural Products, Inc., Adding Peptide Discovery Engine to Broaden Immunology Capabilities, argenx, 09 November 2026