Therapy Areas: Central Nervous System
Rapporteurs Assigned for European Marketing Authorisation Application for Narsoplimab for Treatment of HSCT-TMA
7 June 2019 - - The European Medicines Agency has appointed rapporteurs for the company's marketing authorisation application currently in preparation for narsoplimab for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA), US-based Omeros Corp. (NASDAQ: OMER) said.
Narsoplimab, also known as "OMS721," is Omeros' lead human monoclonal antibody targeting mannan-binding lectin-associated serine protease-2 (MASP-2) and is in Phase 3 clinical programs for the treatment of HSCT-TMA, immunoglobulin A nephropathy, and atypical hemolytic uremic syndrome.
The appointed rapporteurs are members of EMA's Committee for Human Medicinal Products and will jointly coordinate CHMP's evaluation of Omeros' planned MAA for narsoplimab. Omeros intends to request a pre-submission meeting with the rapporteurs to discuss the planned submission of the MAA.
As previously announced, narsoplimab for HSCT-TMA is eligible for submission under EMA's centralized review procedure, which allows submission of a single MAA that, if approved, authorises the product to be marketed in all 31 member states comprising the European Economic Area rather than requiring separate national approvals.
Narsoplimab also has orphan drug designation from EMA for treatment in hematopoietic stem cell transplantation.
Omeros is preparing both a US biologics license application and a European MAA for narsoplimab for the treatment of HSCT-TMA.
Omeros controls the worldwide rights to MASP-2 and all therapeutics targeting MASP-2, a novel pro-inflammatory protein target involved in activation of the complement system, which is an important component of the immune system.
The complement system plays a role in the inflammatory response and becomes activated as a result of tissue damage or microbial infection.
MASP-2 is the effector enzyme of the lectin pathway, one of the principal complement activation pathways.
Importantly, inhibition of MASP-2 does not appear to interfere with the antibody-dependent classical complement activation pathway, which is a critical component of the acquired immune response to infection, and its abnormal function is associated with a wide range of autoimmune disorders.
MASP-2 is generated by the liver and is then released into circulation. Gene-targeted MASP-2-deficient mice and humans with MASP-2 gene polymorphisms that affect MASP-2 serum levels and MASP-2 functional activity are generally healthy with no obvious adverse phenotype.
Phase 3 clinical programmes are in progress for narsoplimab, Omeros' lead MASP-2 inhibitor also known as "OMS721," in hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA), in immunoglobulin A nephropathy, and in atypical hemolytic uremic syndrome.
Narsoplimab can be administered both intravenously and subcutaneously, and Omeros expects to commercialize each formulation of narsoplimab for different therapeutic indications.
In parallel, Omeros is developing small-molecule inhibitors of MASP-2. Based on requests from treating physicians, Omeros has established a compassionate-use program for narsoplimab, which is active in both the US and Europe.
The FDA has granted narsoplimab breakthrough therapy designation for HSCT-TMA and IgA nephropathy; orphan drug status for the prevention (inhibition) of complement-mediated thrombotic microangiopathies, for the treatment of HSCT-TMA and for the treatment of IgA nephropathy; and fast track designation for the treatment of patients with aHUS. 
The European Medicines Agency has granted orphan drug designation to narsoplimab for treatment in HSCT and for treatment of primary IgA nephropathy.
Omeros also has identified MASP-3 as the key activator of the human complement system's alternative pathway and as the enzyme responsible for the conversion of pro-factor D to factor D.
The alternative pathway is linked to a wide range of immune-related disorders. In addition to its lectin pathway inhibitors, the company is advancing its development of antibodies and small-molecule inhibitors against MASP-3 to block activation of the alternative pathway. 
Omeros is scaling up the manufacturing of its MASP-3 antibodies in preparation for clinical trials slated for next year.
In addition to its MASP-2- and MASP-3-specific programmes, Omeros is developing bi-specific inhibitors of MASP-2/MASP-3.
Omeros is a commercial-stage biopharmaceutical company committed to discovering, developing and commercialising small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, complement-mediated diseases, disorders of the central nervous system and immune-related diseases, including cancers.