Omeros Stock Garners High Retail Attention Ahead Of FDA Verdict For Life-Saving Drug

The FDA decision on Narsoplimab, its treatment for post–stem cell and bone marrow transplant complications, is officially due on December 26.

• Omeros said it had resubmitted its FDA application for Narsoplimab in March 2025, with the PDUFA target date later extended to Dec. 26, 2025.
• Narsoplimab analysis in a peer-reviewed study showed a sharp reduction in mortality risk compared with patients who received supportive care alone.
• Decision on the company’s marketing application for Narsoplimab with the EMA is expected in mid-2026.

Omeros Corp. (OMER) shares garnered retail attention in premarket trading on Wednesday as the market looked ahead to a key U.S. Food and Drug Administration (FDA) decision on Narsoplimab, its treatment for post–stem cell and bone marrow transplant complications, due on December 26.

Trading was halted at 06:36 a.m. pending news, according to Nasdaq data.

In a press release last month, Omeros said it had resubmitted its FDA application for Narsoplimab in March 2025, with the PDUFA target date later extended to Dec. 26, 2025, after additional information was provided. A PDUFA date is the FDA's target date to make a decision on a drug application

Management expects the FDA to meet this deadline, noting that all requested analyses continue to show statistically significant evidence supporting the drug’s benefit in Transplant-associated thrombotic microangiopathy (TA-TMA).

How Are Stocktwits Users Saying?

Retail sentiment on Stocktwits shifted to ‘extremely bullish’ from ‘bullish’ a day earlier, amid ‘extremely high’ message volumes. OMER was also among the top trending tickers on the platform.

One user believes that the trading halt is due to news about the potential FDA approval.

Another user, in a post last night, said they expect the FDA approval this morning.

In October, Omeros announced that a peer-reviewed study published in Blood Advances, a journal of the American Society of Haematology, examined survival outcomes in adults with life-threatening TA-TMA treated with Narsoplimab. 

The analysis showed a sharp reduction in mortality risk compared with patients who received supportive care alone, with no new safety concerns reported. Narsoplimab works by blocking MASP-2, a key enzyme in the lectin pathway of the immune system.

The company filed its marketing application for Narsoplimab with the European Medicines Agency (EMA) in June, with a ruling from the EMA’s review committee expected in mid-2026.

Earlier this month, Omeros completed the sale and licensing deal with Novo Nordisk for Zaltenibart, a late-stage antibody drug. The company received $240 million in cash upfront and is eligible for up to $2.1 billion in total milestone payments and royalties.

The company used part of the proceeds to pay down debt and bolster its balance sheet, while the remaining funds will support ongoing operations and the planned U.S. launch of Narsoplimab.

Year-to-date, Omeros' stock has declined more than 11%.

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