ATOSSA THERAPEUTICS, INC. Commitments Disclosure

NOTE 13: COMMITMENTS AND CONTINGENCIES

Litigation and Contingencies

On April 3, 2025, Intas Pharmaceuticals Ltd. (Intas) filed a Petition for Post Grant Review (PGR) with the U.S. Patent and Trademark Office’s (USPTO) Patent Trial and Appeal Board (PTAB) (the 391 PGR Petition) seeking to invalidate one of the

Company’s issued patents (U.S. Patent No. 12,071,391) titled “Methods for Making and Using Endoxifen,” on the alleged grounds of anticipation, obviousness, lack of written description, and lack of enablement.

On April 3, 2025, Intas also filed a Petition for Inter Partes Review (IPR) with the USPTO’s PTAB (the 151 IPR Petition) seeking to invalidate one of the Company’s issued patents (U.S. Patent No. 11,261,151) titled “Methods for Making and Using Endoxifen” (together with U.S. Patent No. 12,071,391, the Patents) on the alleged grounds of anticipation and obviousness.

On November 3, 2025, the PTAB released a Decision Granting Institution of PGR for U.S. Patent No. 12,071,391 and a Decision Granting Institution of IPR for U.S. Patent No. 11,261,151. On January 26, 2026, the Company submitted responses to the 391 PGR Petition and the 151 IPR Petition. Final written decisions are expected for the PGR and IPR proceedings by November 3, 2026.

The Company intends to continue to vigorously contest the 391 PGR Petition and the 151 IPR Petition and believes that the Patents were properly granted and include valid and enforceable claims and that the risk of experiencing financial loss related to the Petitions is remote. However, there can be no assurance that the Company will prevail in contesting either the 391 PGR Petition or the 151 IPR Petition.

From time to time, the Company is subject to other legal proceedings and claims that arise in the ordinary course of its business. The Company believes that these matters do not have a material effect, individually or in the aggregate, on its financial position, results of operations or cash flows.

Contractual Obligations

Contractual obligations represent the Company's future cash commitments and liabilities under agreements with third party clinical trial service providers. Apart from contracts with one third-party clinical trial service provider, such agreements are cancellable upon written notice by the Company. The non-cancellable contracts expire upon completion of the clinical trial and release of the final report, or the contracts may be terminated by the clinical trial service provider, by the FDA or another governmental agency. As of December 31, 2025, the Company's estimated non-cancellable commitment was $7.0 million.