For the most part, the stock market tends to be sedate in the late holiday season. That sure wasn't the case on Wednesday with Omeros (OMER +75.54%), which saw a nearly 76% share price leap after its leading pipeline drug earned U.S. Food and Drug Administration (FDA) approval.
Green light
The FDA's nod came that morning, with the regulator approving Omeros's Yartemlea for hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA), a potentially fatal complication from stem cell transplants. This is the first and only FDA-approved TA-TMA treatment.
Image source: Getty Images.
The drug's solid performance in clinical testing helped get it over the finish line for the biotech. The 100-day survival rate for TA-TMA patients taking Yartemlea was 73% in the drug's pivotal trial.
Omeros is clearly eager to get the medication onto pharmacy shelves. The healthcare company stated that it is finalizing preparations for a January launch; it has already established dedicated billing and reimbursement codes. It will also introduce the YARTEMLE Assist patient support program, which it aims to be operational by some point in the first quarter of 2026.

NASDAQ: OMER
Key Data Points
First on the market
Omeros quoted its CEO, Gregory Demopulos, as saying that "After years of work and close collaboration with the transplant community, we can now offer the first FDA-approved therapy for this frequently fatal complication, with robust response data and a benefit-risk profile that supports confident use in both adults and children."
The company has first-mover advantage here, and with that a very powerful position on the market. Investors were right to trade up the stock on the approval news. Also, considering that Omeros has quite a diverse pipeline for a company of its size, it's positioned for success with other treatments.





