# EDGAR Filing Document

**Accession Number:** 0000894158
**File Stem:** 0001104659-25-102104
**Filing Date:** 2025-10
**Character Count:** 12497
**Document Hash:** 0874cc0570e1551b306400ea57693992
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-102104.hdr.sgml**: 20251024

**ACCESSION NUMBER**: 0001104659-25-102104

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 14

**CONFORMED PERIOD OF REPORT**: 20251024

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20251024

**DATE AS OF CHANGE**: 20251024

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Theriva Biologics, Inc.
- **CENTRAL INDEX KEY:** 0000894158
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 133808303
- **STATE OF INCORPORATION:** NV
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-12584
- **FILM NUMBER:** 251415924

**BUSINESS ADDRESS:**
- **STREET 1:** 9605 MEDICAL CENTER DRIVE
- **STREET 2:** SUITE 270
- **CITY:** ROCKVILLE
- **STATE:** MD
- **ZIP:** 20850
- **BUSINESS PHONE:** (734) 332-7800

**MAIL ADDRESS:**
- **STREET 1:** 9605 MEDICAL CENTER DRIVE
- **STREET 2:** SUITE 270
- **CITY:** ROCKVILLE
- **STATE:** MD
- **ZIP:** 20850

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Synthetic Biologics, Inc.
- **DATE OF NAME CHANGE:** 20120305

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ADEONA PHARMACEUTICALS, INC.
- **DATE OF NAME CHANGE:** 20081027

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** PIPEX PHARMACEUTICALS, INC.
- **DATE OF NAME CHANGE:** 20061214

?xml version='1.0' encoding='ASCII'?

**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 event reported): October 24, 2025**

**THERIVA BIOLOGICS, INC.**

(Exact name of registrant as specified in its charter)

---

| | | |
|:---|:---|:---|
| **Nevada** | **001-12584** | **13-3808303** |
| (State or other jurisdiction of<br> incorporation) | (Commission File No.) | (IRS Employer Identification<br> No.) |

---

**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):

---

| |
|:---|
| Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) |
| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) |
| Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) |
| Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) |

---

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

---

| | | |
|:---|:---|:---|
| &nbsp;&nbsp;**Title of each class** | &nbsp;&nbsp;**Trading Symbol(s)** | &nbsp;&nbsp;**Name of each exchange on<br> which registered** |
| &nbsp;&nbsp;Common stock, par value $0.001 per share | &nbsp;&nbsp;TOVX | &nbsp;&nbsp;NYSE American |

---

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 8.01.** | **Other Events.** |

---

On October 24, 2025, Theriva Biologics, Inc. (the "Company") filed a prospectus supplement and the accompanying base prospectus (the "Prospectus Supplement") to its Registration Statement on Form S-3, as amended (File No. 333-279077), which Form S-3 was declared effective by the Securities and Exchange Commission (the "Commission") on September 25, 2024 (the "Registration Statement"), relating to the offer and sale of up to $4,019,597 of shares of the Company's common stock, par value $0.001 per share (the "common stock"), from time to time through or directly to A.G.P./Alliance Global Partners (the "Sales Agent") pursuant to the terms of that certain Amended and Restated At Market Issuance Sales Agreement, dated February 9, 2021, as amended by Amendment No. 1 thereto, dated May 3, 2021, as further amended by Amendment No. 2 thereto, dated May 2, 2024 (the "Sales Agreement").

Sales of the common stock, if any, under the Prospectus Supplement will be made by any method permitted that is deemed an "at the market offering" as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended (the "Securities Act"). The Sales Agent is not required to sell any specific amount, but will act as our Sales Agent using commercially reasonable efforts consistent with its normal trading and sales practices. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

The Sales Agent will be entitled to compensation at a commission rate equal to up to 3.0% of the gross sales price per share sold. In connection with the sale of the common stock on our behalf, the Sales Agent will be deemed to be an "underwriter" within the meaning of the Securities Act and the compensation of the Sales Agent will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to the Sales Agent with respect to certain liabilities, including liabilities under the Securities Act.

The opinion of the Company's special Nevada counsel (Parsons Behle & Latimer) regarding the validity of the shares of common stock that will be issued pursuant to the Prospectus Supplement and Sales Agreement is filed herewith as Exhibit 5.1 and is incorporated by refence herein.

This Current Report on Form 8-K shall not constitute an offer to sell or the solicitation of an offer to buy any security nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

---

| | |
|:---|:---|
| **Item 9.01.** | **Financial Statements and Exhibits.** |

---

(d) Exhibits.

The following exhibits are filed with this Current Report on Form 8-K:

---

| | |
|:---|:---|
| **Exhibit<br> Number** | **Description** |
| [5.1](tm2529425d2_ex5-1.htm) | [Opinion of Parsons Behle & Latimer](tm2529425d2_ex5-1.htm) |
| [23.1](tm2529425d2_ex5-1.htm) | [Consent of Parsons Behle & Latimer (included in Exhibit 5.1 hereof)](tm2529425d2_ex5-1.htm) |
| 104 | Cover Page Interactive Data File (the cover page XBRL tags are embedded within in the inline XBRL document) |

---

**SIGNATURES**

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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.

---

| | | | |
|:---|:---|:---|:---|
| Dated: October 24, 2025 | **THERIVA BIOLOGICS, INC.** | **THERIVA BIOLOGICS, INC.** | **THERIVA BIOLOGICS, INC.** |
|  | By: | /s/ Steven A. Shallcross | /s/ Steven A. Shallcross |
|  |  | Name: | Steven A. Shallcross |
|  |  | Title: | Chief Executive Officer and Chief Financial Officer |

---

## Exhibit 5.1

**Exhibit 5.1**

![](tm2529425d2_ex5-1img001.jpg)

October 24, 2025

The Board of Directors

Theriva Biologics, Inc.

9605 Medical Center Drive, Suite 270

Rockville, Maryland 20850

---

| | |
|:---|:---|
| **Re:** | **Theriva Biologics, Inc.** |

---

Ladies and Gentlemen:

We have acted as special Nevada counsel to Theriva Biologics, Inc., a Nevada corporation (the "<u>Company</u>"), in connection with the proposed issuance of up to $4,019,597 of shares (the "<u>Shares</u>") of common stock of the Company, par value $0.001 per share (the "<u>Common Stock</u>"). The Shares are included in a Registration Statement on Form S-3 (File No. 333-279077) (the "<u>Registration Statement</u>") filed with the Securities and Exchange Commission (the "<u>Commission</u>") under the Securities Act of 1933, as amended (the "<u>Securities Act</u>"), and declared effective by the Commission on September 25, 2024, a base prospectus, dated September 25, 2024, included in the Registration Statement at the time it originally became effective (the "<u>Base Prospectus</u>"), and a prospectus supplement, dated October 24, 2025, filed on the date hereof with the Commission pursuant to Rule 424(b) under the Securities Act (together with the Base Prospectus, the "<u>Prospectus</u>"). The Shares are being sold pursuant to that certain Amended and Restated At Market Issuance Sales Agreement, dated February 9, 2021, as amended by Amendment No. 1 thereto, dated May 3, 2021, as further amended by Amendment No. 2 thereto, dated May 2, 2024 (the "<u>Sales Agreement</u>"), with A.G.P./Alliance Global Partners (the "<u>Sales Agreement</u>").

This opinion letter is being delivered in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act.

As counsel to the Company, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, we have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. We are opining herein as to the Nevada Revised Statutes (the "<u>NRS</u>"), and we express no opinion with respect to the applicability thereto, or the effect thereon, of the laws of any other jurisdiction or, in the case of Nevada, any other laws, or as to any matters of municipal law or the laws of any local agencies within any state.

We have made such examination as we have deemed necessary for the purpose of this opinion letter. Based upon such examination, it is our opinion, that, when the Shares shall have been duly registered on the books of the transfer agent and registrar therefor in the name or on behalf of the purchasers, and have been issued by the Company against payment therefor (not less than par value) in the circumstances contemplated by the Prospectus and the Sales Agreement, the issuance and sale of the Shares will have been duly authorized by all necessary corporate action of the Company, and the Shares will be validly issued, fully paid and nonassessable.

In rendering the foregoing opinion, we have assumed that (i) the Company will comply with all applicable notice requirements regarding uncertificated shares provided in the NRS and (ii) upon the issuance of any of the Shares, the total number of shares of Common Stock issued and outstanding will not exceed the total number of shares of Common Stock that the Company is then authorized to issue under its articles of incorporation, as amended and restated as of the date hereof.

The Board of Directors

Theriva Biologics, Inc.

October 24, 2025

This opinion letter is given as of the date hereof and we assume no obligation to advise you of changes that may hereafter be brought to our attention. This opinion letter is delivered solely in connection with the consummation of the transactions described herein, and may not be relied upon by you for any other purpose nor by any other person for any purpose.

We hereby consent to the reference to our firm under the caption "Legal Matters" in the Prospectus and to the filing of this opinion letter as Exhibit 5.1 to the Company's Current Report on Form 8-K relating to the issuance and sale of the Shares pursuant to the Sales Agreement. In giving our consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission thereunder.

---

| |
|:---|
| Very truly yours, |
| */s/ Parsons Behle & Latimer* |
| PARSONS BEHLE & LATIMER |

---