Omeros Stock Sinks on Negative EU Opinion for Narsoplimab, Compassionate-Use Program Ends

Omeros Corporation (NASDAQ:OMER) shares are trading lower Friday after the company announced that the European Medicines Agency’s CHMP issued a negative opinion on its marketing authorization application for narsoplimab in TA-TMA, following re-examination of its original negative opinion from June. Omeros stock is feeling bearish pressure. Why are OMER shares down? EMA Panel Upholds Its Negative Opinion on Narsoplimab After Re-Examination CHMP convened an eight-member ad hoc expert group of hematologists, statisticians and transplant physicians, plus two patient representatives, as part of the re-examination. Omeros said the group answered a single, three-part question prepared by CHMP, and that CHMP’s minutes state the group recommended review of individual patient-level data by external experts. Omeros had submitted substantial patient-level data in August as part of its grounds for re-examination, but said CHMP did not provide that data to the group. "We are deeply disappointed in the re-examination process and outcome," said Gregory A. Demopulos, Omeros’ chairman and CEO. He said the YARTEMLEA data, the FDA’s broad approval, a decade of compassionate-use requests from European physicians and rapid U.S. adoption point to a favorable benefit-risk profile. There is no approved TA-TMA therapy in Europe. Omeros Ends Its Compassionate-Use Program and Turns to Named-Patient Access Omeros said that, because of rising U.S. demand for YARTEMLEA, it has told CHMP it plans to end its compassionate-use program. Patients currently receiving the drug through the program will get enough to complete their treatment courses. The company said it is working to enable fully reimbursed, named-patient access in Europe and other regions where permitted. Omeros had planned to license EU commercialization rights to a third party if the EU granted authorization. The U.S. Launch Remains Omeros’ Focus The FDA approved YARTEMLEA in December 2025 for TA-TMA patients two years of age and older. Omeros says it is the first and only approved TA-TMA therapy and the only systemic complement inhibitor on the market without a boxed warning, REMS or vaccination requirement. Omeros reported second-quarter YARTEMLEA gross revenue of $32.2 million, up 190% from the first quarter, and Medicare’s New Technology Add-on Payment for the drug took effect October 1. Omeros plans to begin clinical studies in acute respiratory distress syndrome and in prevention of high-risk TA-TMA in pediatric patients later this year. Read Also: Stock Market Today: Dow, S&P 500 Futures Rise as Bessent Intensifies Economic Pressure on Iran, Treasury Yields Cool Off — TSLA, AA, IBKR in Focus Omeros Stock Falls OMER Price Action: At the time of publication, Omeros shares are trading 2.61% lower at $18.30, according to data from Benzinga Pro. Image via Shutterstock