Narsoplimab

Narsoplimab (OMS721) is our lead antibody targeting MASP-2, the effector enzyme of the lectin pathway of complement.

Narsoplimab (OMS721)

Narsoplimab is a human monoclonal antibody targeting mannan-binding lectin-associated serine protease-2 (MASP-2), the effector enzyme of the lectin pathway of the complement system. The lectin pathway is one of the principal pathways of complement and is activated primarily by tissue damage and microbial infection. Importantly, inhibition of MASP-2 does not appear to interfere with the classical complement pathway, a critical component of the acquired immune response to infection. This novel, proprietary drug is designed to prevent complement-mediated inflammation and endothelial damage while leaving intact the respective functions of the other pathways of innate immunity.

Hematopoietic Stem Cell Transplant-Associated Thrombotic Microangiopathy (HSCT-TMA)

  • Narsoplimab has been granted FDA Breakthrough Therapy designation in patients who have high-risk HSCT-TMA, as well as Orphan Drug designation for the prevention of complement-mediated TMAs and for the treatment of HSCT-TMA. In the European Union, narsoplimab has been designated an Orphan Medicinal Product for treatment in hematopoietic stem cell transplantation.
  • In a late-stage clinical trial compared to an historical control, narsoplimab improved the estimated median overall survival in high-risk HSCT-TMA patients by an order of magnitude and improved 100-day survival by approximately six-fold.
  • With the FDA’s only Breakthrough Therapy designation awarded for this disorder, as well as Orphan Drug designations from both the FDA and the European Medicines Agency, we currently are preparing marketing applications for the approval of narsoplimab in both the US and Europe to treat HSCT-TMA.

Narsoplimab OMS721 MASP-2 antibody inhibitor, breakthrough therapy and orphan drug for HSCT-TMA
Narsoplimab OMS721 MASP-2 antibody inhibitor, breakthrough therapy and orphan drug for IgA nephropathy

IgA Nephropathy

  • Narsoplimab has also received FDA Breakthrough Therapy and Orphan Drug designations for the treatment of IgA nephropathy and Orphan Medicinal Product designation for IgA nephropathy in the European Union.
  • In a Phase 2 clinical trial, narsoplimab reduced proteinuria in IgA nephropathy patients by 50%-90% and stabilized or increased glomerular filtration rates – effects unmatched by any other drug in development for IgA nepropathy.
  • With the FDA’s only Breakthrough Therapy designation awarded for this disorder, as well as Orphan Drug designations from both the FDA and the European Medicines Agency, narsoplimab is advancing through a Phase 3 clinical program to treat IgA nephropathy.

Atypical Hemolytic Uremic Syndrome (aHUS)

  • Narsoplimab has received FDA Fast Track designation for the treatment of aHUS. Phase 2 clinical results are positive and a Phase 3 clinical program is underway.

Narsoplimab OMS721 MASP-2 antibody inhibitor, fast-track designation for aHUS

Access to Investigational Products

***Special Note – April 8, 2020: Unfortunately, due to high demand for our investigational drug narsoplimab (OMS721) through our currently active expanded-access program for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA), Omeros cannot consider additional requests for compassionate use other than for HSCT-TMA at this time. Omeros remains focused on implementing the most rapid and effective processes for providing the product to physicians and their patients across multiple diseases and therapeutic indications, which include ongoing and planned clinical trials. We continue to work with regulatory agencies worldwide to expedite and expand access to narsoplimab as quickly as possible for patients who need it.***

View our pipeline to learn about ongoing narsoplimab clinical studies

Related Pages

Explore our Research Program

View Narsoplimab Publications