MBRX files charter amendment to 500M shares and reports MB-106 trial completion

Rhea-AI Filing Summary

Moleculin Biotech, Inc. reported two corporate actions in this Current Report. Stockholders approved and the company filed a Certificate Amendment to increase authorized common shares from 100,000,000 to 500,000,000, which became effective upon filing with the Delaware Secretary of State on August 21, 2025. The company also furnished a press release dated August 27, 2025 announcing completion of its Phase 1B/2 (MB-106) clinical trial evaluating Annamycin combined with Cytarabine (referred to as AnnAraC) for treatment of subjects with acute myeloid leukemia (AML). The Certificate Amendment and the press release are attached as exhibits.

Positive

• Certificate Amendment effective: authorized common shares increased from 100,000,000 to 500,000,000 and filed with Delaware on August 21, 2025
• Clinical trial milestone: press release announced completion of the Phase 1B/2 (MB-106) trial evaluating Annamycin plus Cytarabine (AnnAraC) for AML on August 27, 2025
• Exhibits furnished: Certificate Amendment filed as Exhibit 3.1 and press release furnished as Exhibit 99.1

Negative

• None.

Insights

Financial Analyst

TL;DR: Company expanded authorized common shares and announced completion of a Phase 1B/2 trial for AnnAraC in AML.

The increase in authorized common shares to 500 million is a structural corporate change that provides the board flexibility for future equity actions; the filing confirms shareholder approval and effectiveness as of August 21, 2025. Separately, the furnished press release reports completion of the Phase 1B/2 MB-106 trial of Annamycin plus Cytarabine. Both developments are material company disclosures: one governance/capital-structure action and one clinical-stage program milestone. Investors will rely on the attached exhibits for full details.

Corporate Governance Expert

TL;DR: Shareholders approved and the company filed an amendment increasing authorized common shares; the change is now effective.

The exhibit filing of the Certificate Amendment documents the formal amendment to the Amended and Restated Certificate of Incorporation, increasing authorized common stock from 100,000,000 to 500,000,000. The 8-K appropriately references the executed amendment as Exhibit 3.1 and includes the press release as Exhibit 99.1. This disclosure aligns with required reporting for charter amendments and Regulation FD furnishing for the press release.

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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): August 21, 2025

MOLECULIN BIOTECH, INC.

(Exact Name of Registrant as Specified in its Charter)

Delaware	001-37758	47-4671997
(State or Other Jurisdiction of Incorporation or Organization)	(Commission File No.)	(I.R.S. Employer Identification No.)

5300 Memorial Drive, Suite 950, Houston, TX 77007

(Address of principal executive offices and zip code)

(713) 300-5160

(Registrant’s telephone number, including area code)

(Former name or former address, if changed from 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-14(c))

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. ☐

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	MBRX	The NASDAQ Stock Market LLC

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Chang in Fiscal Year

As previously disclosed, at the Moleculin Biotech, Inc. (the “Company”) annual meeting of stockholders held on August 18, 2025, the Company’s stockholders approved, among other matters, a proposal to approve a Certificate of Amendment to the Company’s Amended and Restated Certificate of Incorporation (the “Certificate Amendment”) which would amend the Company’s existing certificate of incorporation, as amended, to increase the number of authorized shares of the Company’s common stock from 100,000,000 shares to 500,000,000 shares. The Certificate Amendment became effective upon filing with the Delaware Secretary of State on August 21, 2025.

A copy of the Certificate Amendment is filed as Exhibit 3.1 hereto and is incorporated in this Item 5.03 by reference.

Item 7.01 Regulation FD Disclosure

On August 27, 2025, Moleculin Biotech, Inc. (the “Company”), issued a press release which announced the completion of its Phase 1B/2 (MB-106) clinical trial evaluating Annamycin in combination with Cytarabine (also known as “Ara-C” and for which the combination of Annamycin and Ara-C is referred to as AnnAraC) for the treatment of subjects with acute myeloid leukemia (AML).

A copy of the press release is attached to this report as Exhibit 99.1 and is incorporated by reference herein.

The information contained in Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1, is being furnished and shall not be “filed” for the purpose of the Securities Exchange Act of 1934, as amended (“Exchange Act”), nor shall it be incorporated by reference in any filing under the Exchange Act or the Securities Act of 1933, as amended (“Securities Act”), unless specifically identified therein as being incorporated by reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No. Description

3.1 Amendment to Amended and Restated Certificate of Incorporation of Moleculin Biotech, Inc., dated August 21, 2025

99.1 Press Release dated August 27, 2025

104 Cover page Interactive Data File (formatted as Inline XBRL document)

SIGNATURE

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

	MOLECULIN BIOTECH, INC.
	Date:	August 27, 2025
	By:	/s/ Jonathan P. Foster
		Jonathan P. Foster

FAQ

What change to authorized shares did Moleculin (MBRX) report?

The company increased authorized common stock from 100,000,000 to 500,000,000, effective upon filing on August 21, 2025.

Has Moleculin filed the Certificate Amendment?

Yes. The Certificate Amendment was filed with the Delaware Secretary of State and is attached as Exhibit 3.1 to the Current Report.

What clinical update did Moleculin (MBRX) disclose?

The company furnished a press release announcing completion of the Phase 1B/2 (MB-106) clinical trial evaluating Annamycin plus Cytarabine (AnnAraC) for AML on August 27, 2025.

Are the press release and amendment considered filed or furnished?

The Certificate Amendment is filed as an exhibit; the press release is furnished as Exhibit 99.1 and is expressly stated to be furnished, not filed, under the Exchange Act.