Novo Nordisk acquires new complement system approach to treating rare diseases in Omeros drug deal
Novo Nordisk is spending $240 million to buy global rights to Omeros, a drug that has entered Phase 3 clinical trials and rivals immune disease drugs currently offered by the likes of AstraZeneca, Novartis and Apellis Pharmaceuticals.
The deal brings Novo Nordisk's zaltenibart, an Omeros drug in early stages of development called OMS906. Earlier this year, Seattle-based Omeros began preparations for a pivotal clinical trial of the drug to treat paroxysmal nocturnal hemoglobinuria (PNH), a rare blood disorder. But this spring, Omeros implemented what it told investors was a temporary pause until it received funding to fund research.
The deal announced Wednesday provides Omeros with cash to support the rest of its pipeline, which has another drug currently under regulatory review. Meanwhile, Novo Nordisk acquired an asset that gives it a chance to compete among therapies that target the complement system, part of the immune system.
The complement system has three pathways. Zaltenibart is an antibody designed to inhibit MASP-3, a protein that activates the so-called alternative pathway. Omeros believes that blocking MASP-3 has potential applications in many diseases associated with overactivation of this pathway. One of these is PNH, in which the complement system mistakenly attacks and destroys red blood cells, causing patients to have low levels of healthy red blood cells and other complications. In Phase 2 testing in PNH, Omeros reported that zatinibate produced statistically significant and clinically meaningful improvements in measures of destruction of these cells. The investigational drug has been safe and well-tolerated in clinical testing so far.
Complement inhibitors are already the standard treatment for PNH, mainly AstraZeneca’s blockbuster drugs Soliris and Ultomiris. Both are antibodies designed to block a complement protein called C5. Apellis Pharmaceuticals' peptide drug Empaveli treats PNH by blocking complement protein C3. Novartis' Fabhalta is an oral small molecule designed to block the complement protein factor B, providing an alternative approach to treating PNH.
Omeros' Phase 2 trial of zatinibatin included some patients with PNH who had not responded adequately to AstraZeneca's Ultomiris. In addition to Ultomiris, these participants also received zaltenibart. Omeros reported that patients receiving the drug combination experienced statistically significant and clinically meaningful improvements in hemoglobin levels and measures of immature red blood cells in the circulation. Sustained responses were observed at week 24, the last time point before the interim analysis cutoff. The results were presented at last year's American Society of Hematology annual meeting.
Omeros is planning a Phase 3 program that will evaluate zatinibate head-to-head against AstraZeneca's C5 inhibitor, with the goal of showing superiority relative to these drugs. Omeros said in its annual report that data from these studies could form the basis for superiority claims “for promotion, enhanced market access, and pricing that reflects the advantages of zatinibate.”
In addition to PNH, Omeros is developing zatinibate for the treatment of complement 3 glomerulopathy (C3G), a disease that occurs when C3 protein builds up, causing inflammation and damage in the kidneys. In March, Novartis' Fabhalta expanded its label to C3G, becoming the first FDA-approved treatment for the rare kidney disease. Apellis' Empaveli added C3G to its label in July. Novo Nordisk said it plans to launch a global Phase 3 program of zatinibate in PNH and explore the drug's use in other rare diseases.
“Zaltenibart has a novel mode of action that offers multiple advantages over other treatments for complement-mediated diseases,” Martin Holst Lange, Novo Nordisk's chief scientific officer and executive vice president of research and development, said in the pharma giant's deal announcement. “Novo Nordisk is well-positioned to build on the work done at Omeros to maximize the value of this asset and develop zaltenibart as a differentiated and potentially best-in-class treatment for multiple rare blood and kidney diseases.”
Omeros owns a preclinical MASP-3 program unrelated to zaltenibart and will retain rights thereto. The biotech's research also includes oral, small-molecule MASP-3 inhibitors. The agreement allows Omeros to develop and commercialize these assets under “limited indication restrictions.” The companies expect to complete the deal by the end of this year.
Under the terms of the agreement, Novo Nordisk received exclusive global rights to develop and commercialize zatinibate for all indications. Financials for the deal are broken down into a $240 million cash payment at closing and up to $510 million related to development and approval milestones, according to an Omeros regulatory filing. Additional amounts related to the achievement of sales milestones are up to $1.3 billion.
With Novo Nordisk taking over development of zatinibat, Omeros can continue to focus on narsoplimab, a MASP-2 inhibitor that addresses the lectin pathway of the complement system. The antibody drug is currently under review by the FDA and the European Medicines Agency for the treatment of hematopoietic stem cell transplant-related thrombotic microangiopathy, a rare complication that can occur after stem cell transplant surgery. Current treatment options include complement inhibitors. The FDA is expected to make a decision on narsoplimab on December 26; the EMA is expected to issue a ruling in mid-2026.
Illustration: virusowy, Getty Images
