MBRX advances MIRACLE AML trial with 60% of initial 45-patient target

Rhea-AI Filing Summary

Moleculin Biotech reported progress in its pivotal Phase 2B/3 MIRACLE study of Annamycin plus cytarabine for adult AML patients who are refractory to or relapsed after induction therapy. As of November 4, 2025, 60% of the target number of subjects for the first planned interim unblinding had consented.

The first interim unblinding targets 45 subjects. The company expects to complete treatment of these first 45 subjects in Q1 2026, with the initial unblinding of data thereafter. Identification and recruitment are ongoing. The update was announced via press release furnished as Exhibit 99.1.

Insights

Biotech clinical trials analyst

Enrollment has reached 60% toward the first 45-patient interim readout.

The update centers on subject consent for the first planned interim analysis in the Phase 2B/3 AML study of Annamycin plus cytarabine. The filing states that 60% of the target for this readout had consented as of November 4, 2025, indicating steady recruitment.

The design calls for an initial unblinding after treatment of 45 subjects. The company expects treatment completion in Q1 2026, with the initial unblinding thereafter. Actual timelines and interpretability will depend on enrollment pace and data readiness as recruitment continues.

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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): November 13, 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 7.01 Regulation FD Disclosure

On November 13, 2025, Moleculin Biotech, Inc. (the “Company”), issued a press release which provided an enrollment update with 60% of the target number of subjects for the first planned interim unblinding of data having consented to its pivotal Phase 2B/3 “MIRACLE” study of Annamycin in combination with cytarabine for the treatment of adult patients with acute myeloid leukemia (AML) who are refractory to or relapsed after induction therapy. The targeted number for the first unblinding of data is 45 subjects. This update is as of November 4, 2025, as identification and recruitment are ongoing. The Company expects to complete treatment of the first 45 subjects in the first quarter of 2026 with the initial unblinding of data thereafter.

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

99.1	Press Release dated November 13, 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:	November 13, 2025
	By:	/s/ Jonathan P. Foster
		Jonathan P. Foster

FAQ

What did MBRX announce in the 8-K?

The company reported that 60% of the target subjects for the first interim unblinding in its MIRACLE Phase 2B/3 AML study had consented as of November 4, 2025.

How many subjects are targeted for the first interim unblinding in MBRX's MIRACLE study?

The first interim unblinding targets 45 subjects.

When does Moleculin expect to complete treatment for the first interim analysis cohort?

The company expects to complete treatment of the first 45 subjects in Q1 2026, with the initial unblinding thereafter.

What patient population is being studied in MBRX's MIRACLE trial?

Adult AML patients who are refractory to or relapsed after induction therapy.

What is the intervention being tested in the MIRACLE study?

Annamycin in combination with cytarabine.

How was the update disclosed?

Through a press release furnished as Exhibit 99.1 to the 8-K.