Tranche Update on Atossa Therapeutics, Inc.'s Equity Buyback Plan announced on June 27, 2023.

Atossa Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing medicines in areas of unmet medical need in oncology with a focus on breast cancer. The Company’s lead drug candidate under development is oral (Z)-endoxifen, which the Company is developing in two settings: one to treat breast cancer by reducing tumor cell activity prior to surgery and another to reduce breast tissue density in women. Its programs under development include (Z)-endoxifen Programs, AT-H201, and other programs. (Z)-endoxifen is an active metabolite of tamoxifen, to treat and prevent breast cancer in high-risk women. It is developing a form of (Z)-endoxifen, which is administered orally for the potential treatment of breast cancer and reduction of breast density. AT-H201 is for lung injury caused by cancer treatments. AT-H201 consists of a combination of two drugs to treat other diseases. Its other programs include Immunotherapy/CAR-T Programs, which is in early stage of development.