ATOS Stock Drops After Hours On Earnings Miss — CEO Now Bets On New Uses For Its Experimental Cancer Drug

• The investigational therapy was granted Rare Pediatric Disease designation for the treatment of DMD in December and an Orphan Drug Designation in January. 
• The company reported net loss per share of $4.04 for 2025, compared to a loss of $3.04 in 2024, and above an analyst estimate of a loss of $3.91.
• Last month, Atossa said that the company will not proceed with advancing its drug in metastatic breast cancer.

Shares of Atossa Therapeutics (ATOS) slipped 4% after hours on Wednesday after the company said that it continues to align its resources towards potential commercialization of (Z)-endoxifen after it reported a wider full year loss.

The company said that it is working to advance its experimental drug (Z)-endoxifen in certain rare disease indications such as Duchenne Muscular Dystrophy (DMD) and McCune-Albright Syndrome (MAS) in addition to breast cancer. The investigational therapy was granted Rare Pediatric Disease designation for the treatment of DMD in December and an Orphan Drug Designation in January.

“We believe these FDA designations are important for future development as they both help to speed the FDA review process as well as provide potential financial benefits in the future," CEO Steven Quay said on Wednesday.

Last month, Atossa said that the company will not proceed with advancing its drug in metastatic breast cancer due to the overall cost and timeline required to conduct later-stage studies in the indication. The company then said it will prioritize its resources on other oncology and rare disease areas with “higher potential returns on investments.”

Q4 Earnings

The company said on Wednesday that its operating expenses rose in 2025 to $37.1 million, compared to $9.5 million in 2024, owing to a significant rise in research and development expenses for (Z)-endoxifen.

The company reported net loss per share of $4.04 for 2025, compared to a loss of $3.04 in 2024, and above an analyst estimate of a loss of $3.91. The company ended the year with cash and cash equivalents of $41.29 million, compared to $71.08 million as of 2024-end.

How Did Stocktwits Users React?

On Stocktwits, retail sentiment around ATOS stock stayed within the ‘bullish’ territory over the past 24 hours, while message volume stayed at ‘normal’ levels.

ATOS stock has dropped 50% over the past 12 months. 

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