8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest eventreported): October 2, 2023

THERIVA BIOLOGICS, INC.

(Exact name of registrant as specified in its charter)

9605 Medical Center Drive, Suite 270

Rockville, Maryland 20850

(Address of principal executive offices and zip code)

(301) 417-4364

Registrant’s telephone number, including area code

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in in Rule 405 of the Securities Act of 1933 (17 CFR §230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by checkmark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 5.07. Submission of Matters to a Vote of Security Holders.

On October 2, 2023, Theriva Biologics, Inc. (the “Company”) held the 2023 Annual Meeting where the Company’s stockholders voted on the following two (2) proposals and cast their votes as described below. These matters are described in detail in the Definitive Proxy Statement.

The final results for Proposals 1 and 2 as set forth in the Definitive Proxy Statement were as follows:

Proposal 1 — Election of Directors.

The following four (4) individuals were elected as directors, to serve until the Company’s next annual meeting of stockholders and until their respective successors have been duly elected and qualified with the following votes:

Proposal 2 — Ratification of the appointment of BDO USA P.C. as the Company’s independent registered public accounting firm for the year ending December 31, 2023.

The stockholders ratified and approved the appointment of BDO USA P.C. as the Company’s independent registered public accounting firm for the year ending December 31, 2023 based on the votes listed below:

Item 9.01. Financial Statements and Exhibits.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.