Omeros Shares Double as FDA Approves Transplant Drug Yartemlea
The landmark approval for Yartemlea (narsoplimab) marks a major turnaround after a previous regulatory rejection in 2021.
Shares of Omeros Corporation (NASDAQ: OMER) surged more than 80% on Tuesday after the company announced it had received U.S. Food and Drug Administration (FDA) approval for its drug, Yartemlea (narsoplimab), to treat a rare and often fatal complication of stem cell transplants.
The biopharmaceutical company’s stock climbed by as much as 82.9%, closing at $3.75 and adding over $100 million to its market capitalization. The dramatic rally followed the FDA’s decision to approve Yartemlea for treating transplant-associated thrombotic microangiopathy (TA-TMA) in adult and pediatric patients, making it the first and only approved therapy for the condition.
TA-TMA is a life-threatening condition that can occur after hematopoietic stem cell transplantation, leading to blood clots in the body's small blood vessels. In its most severe forms, the mortality rate can exceed 80%. The approval of Yartemlea addresses a significant unmet medical need for a patient population with no other approved treatment options.
The company confirmed the approval in a press release, noting a U.S. launch is planned for January 2026. The FDA's decision was based on a pivotal trial where 61% of patients treated with Yartemlea achieved a complete response. Notably, the drug's label will not require a boxed warning, signaling a strong safety profile.
"This approval is a watershed moment for patients and a transformative milestone for Omeros," said Dr. Gregory A. Demopulos, Chairman and CEO of Omeros. "We are grateful to the patients, families, and clinicians who participated in our trials and are working to make Yartemlea available to them as quickly as possible."
Tuesday's approval marks a significant victory and a dramatic reversal of fortune for Omeros and its lead drug candidate. In October 2021, the company received a Complete Response Letter (CRL) from the FDA, which stated that the agency had identified deficiencies in the application that precluded approval at the time. The 2021 rejection caused the company's shares to plummet by over 40% as investors questioned the drug's path forward.
Following the CRL, Omeros initiated a formal dispute resolution process with the FDA, leading to the resubmission of its Biologics License Application (BLA) and, ultimately, this week's approval. The successful outcome validates the company's persistence and the clinical data supporting narsoplimab's efficacy.
Analysts see the approval as a major de-risking event for Omeros, which has several other assets in its pipeline. Prior to the news, Wall Street had a consensus "Buy" rating on the stock with a price target of $9.00, suggesting further upside even after the recent rally. The successful commercialization of Yartemlea will now be a key focus for investors, as the orphan drug designation could allow for premium pricing and a significant revenue opportunity for the Seattle-based company.