Omeros Submits MAA To EMA For Narsoplimab For Treatment Of Hematopoietic Stem Cell Transplant-Associated Thrombotic Microangiopathy

Omeros Corporation (NASDAQ:OMER) today announced the recent submission of a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) for narsoplimab for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA).

The MAA includes response-based analyses in narsoplimab-treated TA-TMA patients as well as analyses comparing overall survival between narsoplimab-treated patients and a well-matched external control group. Collectively, the results demonstrate a 61% response rate and, compared to the matched external control, a three-fold improvement in overall survival. The submission also includes outcomes in over 130 TA-TMA patients treated with narsoplimab under Omeros' expanded access program.

Narsoplimab has been granted orphan drug designation by the EMA for treatment in hematopoietic stem cell transplant, enabling review of the MAA through the centralized procedure. This allows for a single marketing authorization to cover all EU member states and the European Economic Area countries of Iceland, Liechtenstein and Norway.

The review procedure begins in mid-July and will follow a standard review timeline. The Committee for Medicinal Products for Human Use (CHMP) will conduct the scientific assessment and will issue an opinion at the end of the review. This opinion is typically adopted by the European Commission, with a final decision expected in mid-2026.

The MAA submission follows the acceptance for review by the U.S. Food and Drug Administration (FDA) of the resubmission of the Biologics License Application (BLA) for narsoplimab for the treatment of TA-TMA. The resubmission was assigned a Prescription Drug User Fee Act (PDUFA) target action date of September 25, 2025.