XOMA Buys Mezagitamab Royalty and Milestone Rights from BioInvent for up to $30M

On May 27, 2025, XOMA Royalty Corporation, a biotech royalty aggregator, and BioInvent International AB, a company engaged in the discovery and development of immune-modulatory antibodies for cancer immunotherapy, announced a significant transaction. XOMA Royalty has acquired the future royalty and milestone interests in mezagitamab (TAK-079) from BioInvent for a closing payment of $20 million, with the total transaction potentially reaching $30 million.

Brad Sitko, Chief Investment Officer of XOMA Royalty, emphasized that the deal strengthens XOMA Royalty's late-stage royalty portfolio by enhancing their stake in a promising Phase 3 program. Sitko highlighted the long-term partnership with BioInvent, rooted in XOMA’s legacy technology that contributed to the development of mezagitamab. He expressed satisfaction with providing BioInvent non-dilutive funding to further its proprietary pipeline.

Martin Welschof, CEO of BioInvent, underscored the value of BioInvent's n-CoDeR® platform, which has led to the discovery of several promising antibody drug candidates currently in mid-to-late-stage trials. He noted that the transaction reflects XOMA Royalty’s increased interest in mezagitamab, supports BioInvent's strategy of value creation through partnerships, and provides a financial boost to focus on advancing their own clinical development programs.

The foundation of the future royalty and milestone interests in mezagitamab dates back to a 2003 cross-licensing agreement between XOMA Royalty’s bacterial protein expression technology and BioInvent’s n-CoDeR® antibody library. Under the purchase terms, XOMA Royalty paid $20 million to BioInvent at closing and will pay an additional $10 million upon a specific regulatory milestone related to marketing approval for mezagitamab in IgA nephropathy by the U.S. Food and Drug Administration.

XOMA Royalty’s entitlement, augmented by the newly acquired interests from BioInvent, includes potential milestones up to $16.25 million from Takeda and mid-single digit royalties on future commercial sales of mezagitamab.

Takeda, the developer of mezagitamab, has announced the initiation of a Phase 3 clinical trial for patients with immune thrombocytopenia. Mezagitamab is a fully human monoclonal antibody targeting CD38 expressing cells, which include plasmablasts, plasma cells, and natural killer cells, leading to their depletion. This characteristic holds the potential for mezagitamab to become a leading anti-CD38 monoclonal antibody.

XOMA Royalty plays a pivotal role in the biotechnology sector by acquiring potential future economics associated with therapeutic candidates licensed to pharmaceutical or biotech companies. Through these acquisitions, XOMA Royalty provides non-dilutive, non-recourse funding to sellers, facilitating advancements in their internal drug candidates or supporting general corporate objectives. The company boasts a growing portfolio of assets, consisting of rights to potential future economics from therapeutic candidates.

BioInvent International AB, listed on Nasdaq Stockholm as BINV, operates as a clinical-stage biotech firm specializing in novel immuno-modulatory antibodies for cancer therapy. It currently has five drug candidates undergoing Phase 1/2 trials for treating hematological cancers and solid tumors. BioInvent’s proprietary F.I.R.S.T™ technology platform identifies potential targets and the antibodies that bind to them, generating promising candidates for its clinical pipeline and offering licensing and partnership opportunities. The company derives revenue from research collaborations, license agreements with leading pharmaceutical firms, and antibody production in its integrated manufacturing unit.