Omeros receives second negative EU opinion on narsoplimab
- Omeros said the European Medicines Agency's CHMP maintained its negative opinion on narsoplimab after re-examining the application for treating transplant-associated thrombotic microangiopathy (TA-TMA).
- An eight-member expert group recommended further patient-level data analysis, according to Omeros, while the company plans to end its European compassionate-use program for new patients.
- Omeros will continue selling FDA-approved YARTEMLEA in the United States and plans to pursue additional indications for its MASP-2 drug development program.
Omeros (NASDAQ:OMER) said Europe's drug review committee maintained its negative opinion on narsoplimab for TA-TMA after re-examination, despite the treatment receiving U.S. approval in December 2025.
The decision follows the committee's initial negative opinion in June 2026, when European regulators identified uncertainties surrounding clinical effectiveness, pediatric dosing and the medicine's overall benefit-risk profile.
"We are deeply disappointed in the re-examination process and outcome," said Omeros Chairman and CEO Gregory A. Demopulos.
According to Omeros, an eight-member expert group recommended further patient-level analysis, while the company said its August submission contained such data that were not provided to the group.
Omeros plans to discontinue its European compassionate-use program for new patients while supplying existing patients through treatment completion and pursuing permitted named-patient access.
The FDA approved narsoplimab under the YARTEMLEA brand in December 2025 for patients aged two years and older with TA-TMA, and U.S. commercial sales began in January 2026.
Omeros is also developing the longer-acting antibody OMS1029 and oral MASP-2 inhibitors, with studies targeting acute respiratory distress syndrome and prevention of high-risk pediatric TA-TMA planned for later in 2026.
