Atossa Therapeutics Appoints Claudia Lopez, DVM, MSc, as Vice President, Clinical Product Development

Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), today announced the appointment of Claudia Lopez, DVM, MSc, as its new Vice President, Clinical Product Development. Dr. Lopez brings more than two decades of clinical development and strategic expertise to Atossa, including leadership roles in global clinical programs across immunology, oncology, and metabolic disease. Atossa Therapeutics is a clinical-stage biopharmaceutical company developing innovative medicines for breast cancer.

Dr. Lopez most recently served as Vice President of Clinical Development at Landos Biopharma, where she oversaw global clinical strategies, trial design, and regulatory alignment. Her leadership has consistently driven successful clinical programs from early-stage development through complex global regulatory processes. In her new role at Atossa, Dr. Lopez will focus on advancing Atossa’s clinical pipeline, contributing to the development and delivery of next-generation cancer treatments.

“We are pleased to welcome Dr. Lopez to the Atossa team. Her extensive experience in clinical development, particularly her strategic acumen in guiding multifaceted clinical trials, aligns perfectly with our mission to bring transformative treatments to women with breast cancer,” said Dr. Steven Quay, Chief Executive Officer of Atossa Therapeutics. “Claudia’s leadership will be instrumental in driving Atossa’s clinical programs forward as we work to improve outcomes for breast cancer patients across the treatment continuum.”

Dr. Lopez has built an impressive career spanning leadership roles at Landos Biopharma, Arena Pharmaceuticals, and Takeda Pharmaceuticals, where she held key positions in clinical development allowing her to successfully lead global programs. She has directed cross-functional teams, led regulatory submissions in the U.S. and Europe, and managed comprehensive clinical development programs in areas such as inflammatory bowel disease, diabetes, melanoma, and breast cancer. Her expertise in aligning clinical strategy with regulatory and commercial goals will be invaluable to Atossa’s growth.

“I am honored to join Atossa at this exciting stage,” said Dr. Lopez. “The potential of Atossa’s pipeline in breast cancer is compelling, and I look forward to contributing my experience to advance these promising therapies.”

About Atossa Therapeutics Atossa Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing innovative medicines in areas of significant unmet medical need in oncology with a focus on using (Z)-endoxifen to prevent and treat breast cancer. For more information, please visit www.atossatherapeutics.com.

Contact Michael Parks, VP Investor and Public Relations 484-356-7105 michael.parks@atossainc.com

FORWARD LOOKING STATEMENTS This press release contains certain information that may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. We may identify these forward-looking statements by the use of words such as “expect,” “potential,” “continue,” “may,” “will,” “should,” “could,” “would,” “seek,” “intend,” “plan,” “estimate,” “anticipate,” “believe,” “future,” or other comparable words. Forward-looking statements in this press release are subject to risks and uncertainties that may cause actual results, outcomes, or the timing of actual results or outcomes, such as data related to the (Z)-endoxifen program, the potential of (Z)-endoxifen as a breast cancer prevention and treatment agent, and potential milestones and growth opportunities for the Company, to differ materially from those projected or anticipated, including risks and uncertainties associated with: macroeconomic conditions and increasing geopolitical instability; the expected timing of releasing data; any variation between interim and final clinical results; actions and inactions by the FDA and foreign regulatory bodies; the outcome or timing of regulatory approvals needed by Atossa, including those needed to continue our planned (Z)-endoxifen trials; our ability to satisfy regulatory requirements; our ability to remain compliant with the continued listing requirements of the Nasdaq Stock Market; our ability to successfully develop and commercialize new therapeutics; the success, costs and timing of our development activities, including our ability to successfully initiate or complete our clinical trials, including our (Z)-endoxifen trials; our anticipated rate of patient enrollment; our ability to contract with third-parties and their ability to perform adequately; our estimates on the size and characteristics of our potential markets; our ability to successfully defend litigation and other similar complaints and to establish and maintain intellectual property rights covering our products; whether we can successfully complete our clinical trial of oral (Z)-endoxifen in women with mammographic breast density and our trials of (Z)-endoxifen in women with breast cancer, and whether the studies will meet their objectives; our expectations as to future financial performance, expense levels and capital sources, including our ability to raise capital; our ability to attract and retain key personnel; our anticipated working capital needs and expectations around the sufficiency of our cash reserves; and other risks and uncertainties detailed from time to time in Atossa’s filings with the Securities and Exchange Commission, including without limitation its Annual Reports on Form 10-K and Quarterly Reports on 10-Q. Forward-looking statements are presented as of the date of this press release. Except as required by law, we do not intend to update any forward-looking statements, whether as a result of new information, future events or circumstances or otherwise.