ATOSSA THERAPEUTICS, INC. Q2 FY2023 earnings call

• Clinical: Three Phase 2 trials ongoing. Karisma-Endoxifen trial has 70% of 240 patients enrolled, expects full enrollment in Q4 2023 and data in mid-2024. I-SPY neoadjuvant trial 30% enrolled. EVANGELINE neoadjuvant trial completed PK run-in with 40mg dose, moving to 80mg dose. Research partnership with Weill Cornell on triple negative breast cancer. - Financial: Cash runway with multi-year resources, share repurchase program authorized to buy up to 10 million shares. - Strategic: Building alliances for Phase 3 development and commercialization.

Cash position at end of Q2 2023 was $99.4 million. Total operating expenses for Q2 were $7.8 million, with net loss of $9.8 million. Interest income was $1 million for Q2. For the six months ended June 30, total operating expenses were $14.9 million, net loss was $16.1 million. R&D expenses for Q2 were $3.7 million, and for six months were $7.2 million. G&A expenses for Q2 were $4.1 million, and for six months were $7.7 million. Interest income for six months was $1.8 million.

• Clinical data from Phase 2 trials expected over next 12-18 months. - Building partnerships for Phase 3 development. - Share repurchase program authorized through year-end 2023.

• Forward-looking statements subject to risks detailed in SEC disclosure documents. - Non-cash impairment charge of $2.9 million on investment in Dynamic Cell Therapies due to cash runway less than a year for its CAR-T business.

Q: About meaningful density reduction in Karisma-Endoxifen trial A: Discussed mammographic density measurement endpoints (A-D categorization and quantitative scores), statistical significance (couple percent) and clinical significance (larger drops and categorization changes) Q: EVANGELINE study sites in Canada A: One site in Canada, ongoing recruitment of additional trial centers Q: Plans to expand pipeline via M&A A: Strong cash balance allows considering adding to pipeline, with intent to assess strategic fits Q: Impairment charge on DCT A: Due to cash runway less than a year for DCT's CAR-T business, but investment still considered valuable Q: Patient enrollment in trials A: I-SPY trial 30% enrolled, Karisma trial on schedule, EVANGELINE trial at Mayo Clinic with buzz