Novo Nordisk Acquires Omeros' Zaltenibart in $2.1B Deal, Aims to Advance PNH Treatment

Novo Nordisk has entered into a $2.1 billion agreement with Omeros Corporation to acquire zaltenibart, a MASP-3 inhibitor for the treatment of paroxysmal nocturnal hemoglobinuria (PNH) and other rare blood and kidney disorders. The deal, announced on October 15, 2025, marks a significant development in the pharmaceutical industry's approach to rare disease treatments.

Strategic Acquisition Amid Industry Shifts

The Danish pharmaceutical giant's move comes at a time of strategic realignment within the company. Novo Nordisk, known for its diabetes and obesity treatments, has recently undergone substantial organizational changes, including layoffs and the cessation of its cell therapy R&D efforts. However, this acquisition signals the company's continued interest in expanding its portfolio in specialized therapeutic areas.

Martin Holst Lange, Novo Nordisk's chief scientific officer, expressed optimism about zaltenibart's potential, stating, "Novo Nordisk is in a strong position to build on the work done by Omeros to maximise the value of this asset and develop zaltenibart into a differentiated and potentially best-in-class treatment approach for a number of rare blood and kidney disorders."

Zaltenibart's Promise and Development History

Zaltenibart has shown promise in the treatment of PNH, a rare blood disorder currently dominated by AstraZeneca's C5 inhibitors, Ultomiris and Soliris. In December 2024, Omeros presented encouraging phase 2 data at the American Society of Hematology annual meeting, demonstrating that zaltenibart resulted in "sustained clinically meaningful improvements in both hemoglobin and absolute reticulocyte count and prevented both intravascular and extravascular hemolysis."

Despite these positive results, Omeros had temporarily paused the zaltenibart program in May 2025 due to financial constraints and the need to prioritize capital allocation. The acquisition by Novo Nordisk breathes new life into the drug's development, with plans to initiate a global phase 3 program for PNH and explore its potential in other rare disorders.

Financial Terms and Future Prospects

The deal structure includes $340 million in upfront and near-term milestone payments, with the potential for Omeros to receive up to $2.1 billion in total, including royalties if zaltenibart reaches the market. This agreement provides Omeros with much-needed capital and allows the company to focus on its other pipeline assets, including narsoplimab, which recently faced an FDA rejection for hematopoietic stem cell transplant-associated thrombotic microangiopathy.

Gregory Demopulos, M.D., CEO of Omeros, commented on the deal: "With Novo Nordisk driving the success of zaltenibart, Omeros remains focused on securing approval and commercialisation of narsoplimab this quarter and continuing to advance its robust development pipeline."

As Novo Nordisk prepares to advance zaltenibart through late-stage clinical trials, the pharmaceutical industry watches closely to see if this strategic acquisition will yield a new leading treatment for PNH and potentially other rare diseases, challenging the current market dominance of AstraZeneca's therapies.