Atossa raises USD 16.5m via direct offering to extend (Z)-endoxifen development runway

Seattle-based Atossa Therapeutics, Inc. (Nasdaq: ATOS) [announced](https://www.prnewswire.com/news-releases/atossa-therapeutics-announces-registered-direct-offering-of-up-to-16-5-million-in-gross-proceeds-302797596.html) a registered direct offering of up to USD 16.5 million in total potential gross proceeds, structured to provide USD 4.5 million in immediate capital while retaining the possibility of an additional USD 12 million contingent on warrant exercises. For a clinical-stage company carrying a USD 34.8 million net loss in 2025 against a year-end cash balance of approximately USD 41.3 million, the offering represents a measured effort to extend runway as the company advances [(Z)-endoxifen ](https://app.allsci.com/drugs/ASC-DR-0000000024896-1.0-1772718717)across oncology and rare disease programs, including Duchenne Muscular Dystrophy and McCune-Albright Syndrome. The financing provides Atossa with USD 4.5 million in upfront gross proceeds through a registered direct sale of common stock to institutional investors, with the potential to raise an additional USD 12 million if accompanying warrants are exercised. The warrants become exercisable six months after issuance and include both longer- and shorter-dated tranches. Rodman & Renshaw acted as exclusive placement agent. Atossa said the proceeds will support clinical development of (Z)-endoxifen and other pipeline programs, as well as general corporate purposes. ## Company overview and pipeline Atossa is a clinical-stage biopharmaceutical company focused on developing (Z)-endoxifen, a potent selective estrogen receptor modulator and degrader (SERM/D) with additional PKC-β1 inhibitory activity. Unlike tamoxifen, which requires metabolic conversion via CYP2D6, (Z)-endoxifen delivers direct pharmacological activity independent of that enzyme, providing more consistent systemic exposure across patient populations with variable CYP2D6 metabolism. The company is evaluating (Z)-endoxifen across multiple clinical settings. In breast cancer, Atossa is conducting the EVANGELINE study in collaboration with the Mayo Clinic, with enrollment expected to conclude by mid-2026 and preliminary data anticipated later that year. A separate arm within the I-SPY 2 adaptive trial, pairing (Z)-endoxifen with Eli Lilly's abemaciclib (Verzenio) in ER+/HER2- early breast cancer, dosed its first patient in August 2024. Beyond oncology, Atossa has expanded (Z)-endoxifen into rare pediatric diseases. The FDA granted Rare Pediatric Disease Designation for DMD in December 2025 and Orphan Drug Designation for DMD in January 2026, along with a separate Rare Pediatric Disease Designation for McCune-Albright Syndrome. These designations are material because upon approval of a qualifying marketing application, Atossa may be eligible for a Priority Review Voucher, which recent market transactions suggest could be worth USD 100 million to USD 200 million. The [full-year 2025 financial results](https://www.prnewswire.com/news-releases/atossa-therapeutics-reports-fourth-quarter-and-year-end-2025-financial-results-and-provides-a-corporate-update-302725388.html) disclosed total operating expenses of USD 37.1 million, up 34% year-over-year, driven primarily by a 50% increase in R\&D spending to USD 21.2 million as clinical trial activity accelerated. With cash of USD 41.3 million at year-end 2025 and the burn rate observed in 2025, the ATOS registered direct offering provides a modest but incremental capital buffer without the dilution of a larger equity raise.. *** This article was generated with AI assistance and reviewed and edited by the AllSci editorial team Explore more at AllSci News: [https://allsci.com/news/](https://allsci.com/news/) --- Spot something wrong? [Report an issue with this article](https://newsgen-prod.reframedata.com/feedback/atossa-therapeutics-funding-raises-usd-165m)