Omeros Faces Second Rejection Of Narsoplimab In Europe – OMER Stock Falls Below Key Support For First Time In Nearly 3 Months

• The stem cell transplant-associated complications can be potentially fatal.
• Narsoplimab received FDA approval in December 2025 under the brand name Yartemlea.
• Narsoplimab is the first approved treatment for TA-TMA in patients aged two years and older.

Omeros Corporation (OMER) was on investors’ radar on Friday after the European Medicines Agency (EMA) issued a negative opinion on the marketing application for its treatment of stem cell transplant-associated complications, marking a second such stance in four months.

OMER shares were down 4.8% in pre-market. If the levels hold after the opening bell, the stock would fall below its key 50-day moving average (50-DMA) for the first time in nearly three months.

EMA’s First Rejection Came In June

On Friday, European regulators rejected Omeros’ application for Narsoplimab, which is used to treat hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA). The complication can be potentially fatal.

The regulator rejected the first application in June, citing insufficient evidence that the drug was effective, including the lack of a placebo group. Omeros challenged the original decision and submitted additional patient data in August. However, the company said the committee did not share those records with an independent expert group reviewing the treatment.

“We are deeply disappointed in the re-examination process and outcome. We believe that our Yartemlea efficacy and safety data, FDA’s recent approval with a broad indication for both adults and children, a decade of compassionate use requests by European transplant physicians for their TA-TMA patients, and the rapid U.S. commercial adoption speak clearly to the favorable benefit-risk profile of the drug,” said Gregory A. Demopulos, M.D., chairman and CEO.

Narsoplimab Received FDA Approval Last December

Narsoplimab is already approved in the U.S., having received Food and Drug Administration (FDA) approval in December 2025 under the brand name Yartemlea. The formulation was the first approved treatment for TA-TMA in patients aged two years and older.

Omeros began commercial sales in January 2026, generating $28.5 million in net revenue during the second quarter (Q2). Omeros reported $132 million in cash and short-term investments as of June 30, 2026.

Retail’s Take On OMER

Retail sentiment surrounding OMER on Stocktwits remained ‘bearish’ over the past 24 hours, amid ‘high’ message volumes.

One bullish user expects Omeros’ Q3 results to “fly” and the stock to climb back over $20.

The stock is up nearly 15% so far this year.

Also read: Why Are SPCX, ECHO, KO Stocks Moving Premarket Today?

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