Atossa Therapeutics Inc.

Atossa Therapeutics Inc. is a clinical-stage biopharmaceutical company headquartered in Seattle, Washington. Founded in 2008, the company is publicly traded on NASDAQ under the ticker symbol ATOS. As of May 2026, Atossa Therapeutics has a market capitalization of approximately $42-43 million USD. Employee counts have varied, with some sources reporting around 8 to 16 employees as of late 2025.

The company focuses on developing proprietary medicines for oncology, primarily breast cancer and related conditions, and also explores treatments for rare diseases. Their lead product candidate is oral (Z)-endoxifen, a selective estrogen receptor modulator and degrader (SERM/SERD) currently in Phase 2 clinical development for the treatment and prevention of breast cancer. (Z)-endoxifen has also received Orphan Drug Designation and Rare Pediatric Disease designation from the U.S. FDA for Duchenne Muscular Dystrophy and McCune-Albright Syndrome. Historically, Atossa Therapeutics also offered diagnostic tests such as ForeCYTE and ArgusCYTE.

In terms of patent litigation, Atossa Therapeutics Inc. demonstrates a posture of enforcing its intellectual property. The company has appeared as a plaintiff in one tracked case and has no recorded appearances as a defendant. This indicates an active role in asserting its patent portfolio rather than primarily defending against infringement claims.

The sole tracked case involving Atossa Therapeutics Inc. is Atossa Therapeutics Inc. v. Jina Pharmaceuticals Inc., filed at the Patent Trial and Appeal Board (PTAB) on December 10, 2025. This case highlights the company's engagement in challenging patents or defending its own in a specialized patent forum.