Material Event Form 8 K

On September 6, 2024, Theriva Biologics, Inc. (the "Company") received a notice of conversion from the holder of 4,138 shares of its Series C Convertible Preferred Stock and 100,000 shares of its Series D Convertible Preferred Stock to convert the 4,138 shares of Series C Convertible Preferred Stock into 1,086 shares of the Company's common stock at a conversion price of $30.50 per share and to convert the 100,000 shares of Series D Convertible Preferred Stock into 26,230 shares of the Company's common stock at a conversion price of $30.50 per share. On September 6, 2024, the Company issued an aggregate of 27,316 shares of its common stock upon conversion of such shares of Series C Convertible Preferred Stock and Series D Convertible Preferred Stock. Upon such conversion there are no shares of Series C Convertible Preferred Stock or Series D Convertible Preferred Stock outstanding.