Atossa Therapeutics, Inc. (NASDAQ: ATOS) completed a registered direct offering that raised $4.5 million in gross proceeds before deducting placement agent fees and other offering expenses, according to a company statement.

The Seattle-based clinical-stage biopharmaceutical company sold 1,363,637 shares of common stock at $0.18 per share, along with Series A and Series B warrants to purchase an additional 1,363,637 shares each. The warrants become exercisable six months after issuance, with Series A warrants expiring after 5.5 years and Series B warrants expiring after two years.

If all warrants are exercised for cash, the company could receive up to an additional $12 million in gross proceeds, bringing the total potential offering amount to approximately $16.5 million. The company noted that no assurance can be given that any warrants will be exercised.

Rodman & Renshaw LLC served as the exclusive placement agent for the offering. The securities were offered through a shelf registration statement on Form S-3 that was filed with the Securities and Exchange Commission on May 13, 2024, and declared effective on May 23, 2024.

Atossa plans to use the net proceeds for clinical development of its product candidates, working capital and general corporate purposes. The company is developing treatments in oncology and other areas of unmet clinical need, with its lead product candidate (Z)-endoxifen currently in development across several clinical settings.