Form 8-K

8-K — SOLIGENIX, INC.

Accession: 0001104659-26-078251

Filed: 2026-06-26

Period: 2026-06-26

CIK: 0000812796

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — sngx-20260626x8k.htm (Primary)

EX-5.1 (sngx-20260626xex5d1.htm)

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8-K

8-K (Primary)

Filename: sngx-20260626x8k.htm · Sequence: 1

Soligenix, Inc._June 26, 2026

0000812796falseDE00008127962026-06-262026-06-26

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): June 26, 2026

Commission File No. 001-14778

Soligenix, Inc.

(Exact name of small business issuer as specified in its charter)

DELAWARE

41-1505029

(State or other jurisdiction of

incorporation or organization)

(I.R.S. Employer

Identification Number)

29 Emmons Drive,

Suite B-10

Princeton, NJ

08540

(Address of principal executive offices)

(Zip Code)

(609) 538-8200

(Issuer’s telephone number, including area code)

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:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, par value $.001 per share

SNGX

The Nasdaq Capital Market

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

Emerging growth company ☐

If an emerging growth company, indicate by check mark 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 June 26, 2026, Soligenix, Inc. (the “Company”) filed a prospectus supplement (the “Current Prospectus Supplement”) to increase the maximum aggregate offering amount of the shares of the Company’s common stock, par value $0.001 per share, issuable under the At Market Issuance Sales Agreement, dated January 23, 2026 (the “Sales Agreement”), with Rodman & Renshaw LLC, by an additional aggregate amount of $2,500,000. The Company previously sold approximately $6,234,000 of shares of common stock pursuant to the Sales Agreement under prior prospectus supplements covering an aggregate of up to $6,406,000 of shares of common stock. A copy of the legal opinion as to the legality of the $2,500,000 of shares of common stock issuable under the Sales Agreement and covered by the Current Prospectus Supplement is filed as Exhibit 5.1 attached hereto.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.

Description

5.1

Opinion of Duane Morris LLP

23.1

Consent of Duane Morris LLP (included in Exhibit 5.1)

104

Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

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.

Soligenix, Inc.

June 26, 2026

By:

/s/ Christopher J. Schaber

Christopher J. Schaber, Ph.D.

President and Chief Executive Officer

(Principal Executive Officer)

EX-5.1

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EXHIBIT 5.1

NEW YORK

LONDON

SINGAPORE

PHILADELPHIA

CHICAGO

WASHINGTON, DC

SAN FRANCISCO

SILICON VALLEY

SAN DIEGO

LOS ANGELES

BOSTON

HOUSTON

DALLAS

FORT WORTH

AUSTIN

FIRM and AFFILIATE OFFICES

HANOI

HO CHI MINH CITY

SHANGHAI

ATLANTA

BALTIMORE

WILMINGTON

MIAMI

BOCA RATON

PITTSBURGH

NORTH JERSEY

LAS VEGAS

CHERRY HILL

LAKE TAHOE

MYANMAR

ALLIANCES IN MEXICO

www.duanemorris.com

June 26, 2026

Soligenix, Inc.

Attn: Board of Directors

29 Emmons Drive, Suite B-10

Princeton, NJ 08540

Re:

Soligenix, Inc. (the “Corporation”) Form S-3, as amended (Registration File No. 333-274265) (the “Registration Statement”), as supplemented by the Prospectus Supplements dated January 23, 2026, May 28, 2026 and June 26, 2026 (collectively, the “Prospectus Supplements”)

Ladies and Gentlemen:

We have acted as special counsel to the Corporation in connection with the preparation and filing with the U.S. Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”), of the Registration Statement as supplemented by the Prospectus Supplements, relating to the offer and sale by the Corporation of shares of common stock, $0.001 par value, of the Corporation having an aggregate gross sales price of up to $2,500,000 covered by the Prospectus Supplement dated June 26, 2026 (the “Shares”), pursuant to the terms of the At Market Issuance Sales Agreement dated as of January 23, 2026 (the “Agreement”) between the Corporation and Rodman & Renshaw LLC, as sales agent.

As counsel to the Corporation, we have supervised all corporate proceedings in connection with the preparation and filing of the Registration Statement as supplemented by the Prospectus Supplements.

For purposes of rendering this opinion, we have examined originals or copies (certified or otherwise identified to our satisfaction) of:

a.the Registration Statement, in the form filed and to be filed with the Commission, and the exhibits filed or to be filed in connection therewith, including the Prospectus Supplements;

Duane Morris llp

Boca Center Tower II, 5100 Town Center Circle, suite 400 PHONE: +1 561 962 2100 FAX: +1 561 962 2101BOCA RATON, FL 33486-1008‌

DM3\22782592.1

Soligenix, Inc.

June 26, 2026

Page 2

b.the Agreement;

c. the Second Amended and Restated Certificate of Incorporation of the Corporation, as amended, as certified by the Secretary of the Corporation;

d. the Second Amended and Restated Bylaws of the Corporation, as certified by the Secretary of the Corporation; and

e. resolutions of the Board of Directors of the Corporation, as attested to by the Secretary of the Corporation.

We have also examined such other certificates of public officials, such certificates of executive officers of the Corporation and such other records, agreements, documents and instruments as we have deemed relevant and necessary as a basis for the opinions hereafter set forth.

In such examination, we have assumed (i) the genuineness of all signatures, (ii) the legal capacity of all natural persons, (iii) the authenticity of all documents submitted to us as originals, (iv) the conformity to original documents of all documents submitted to us as certified, conformed or other copies and the authenticity of the originals of such documents and (v) that all records and other information made available to us by the Corporation on which we have relied are complete in all material respects. As to all questions of fact material to the opinion expressed herein, we have relied solely upon the above-referenced certificates or comparable documents and upon the representations and warranties contained in the Agreement and other documents delivered pursuant thereto, have not performed or had performed any independent research of public records and have assumed that certificates of or other comparable documents from public officials dated prior to the date hereof remain accurate as of the date hereof.

Based on the foregoing, we are of the opinion that the Shares, when issued pursuant to the terms of the Agreement against receipt by the Corporation of the consideration specified therein, will be validly issued, fully paid and non-assessable.

The foregoing opinion is limited to the laws of the State of Delaware, and we do not express any opinion herein concerning any other law.

The opinion expressed herein is rendered as of the date hereof and is based on existing law, which is subject to change. Where our opinion expressed herein refers to events to occur at a future date, we have assumed that there will have been no changes in the relevant law or facts between the date hereof and such future date. We do not undertake to advise you of any changes in the opinion expressed herein from matters that may hereafter arise or be brought to our attention or to revise or supplement such opinions should the present laws of any jurisdiction be changed by legislative action, judicial decision or otherwise.

Soligenix, Inc.

June 26, 2026

Page 3

Our opinion expressed herein is limited to the matters expressly stated herein and no opinion is implied or may be inferred beyond the matters expressly stated.

We hereby consent to the use of this letter as Exhibit 5.1 to the Current Report on Form 8-K filed by the Corporation on June 26, 2026 and which is incorporated by reference into the Prospectus, and to any and all references to our firm in the Prospectus which is a part of the Registration Statement and the Prospectus Supplements. In giving this consent, we do not admit that we are “experts” within the meaning of Section 11 of the Securities Act or within the category of persons whose consent is required under Section 7 of the Securities Act.

Very truly yours,

/s/ Duane Morris LLP

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Document and Entity Information

Jun. 26, 2026

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