Moleculin Biotech, Inc. (MBRX) SEC Filings

Moleculin Biotech, Inc. (MBRX) is the subject of a Schedule 13D filing by its Executive Vice President and Chief Financial Officer, Jonathan P. Foster, who reports beneficial ownership of 1,288,207 shares of common stock, representing 6.3% of the company’s outstanding shares.

The position consists of 305,673 shares held directly, 879,999 shares underlying Series I Common Stock Purchase Warrants, and 102,535 shares underlying options and other warrants exercisable within 60 days of August 19, 2026. Foster acquired 293,333 shares and the Series I warrants in an August 3, 2026 public offering at a combined price of $0.75 per share plus three warrants, for about $219,999.75, using personal funds. The warrants are exercisable at $0.75 per share until August 3, 2031, include a beneficial ownership limitation (increased by election from 4.99% to 9.99% effective October 18, 2026), an anti-dilution provision with a floor price of $0.21, and a right to receive the Black Scholes Value in certain fundamental transactions.

Moleculin Biotech, Inc. (MBRX) received a Schedule 13D from its Chairman, Chief Executive Officer and President, Walter V. Klemp, and his holding company AnnaMed, Inc., reporting significant ownership in the company’s common stock.

As of this filing, Mr. Klemp may be deemed to beneficially own 2,070,761 shares of common stock of Moleculin, representing 9.87% of the 19,477,380 shares outstanding as of August 6, 2026. This position includes 564,976 shares of common stock (564,340 held directly and 636 held through AnnaMed), 1,250,959 shares underlying currently exercisable Series I Common Stock Purchase Warrants, and 254,826 shares underlying options and other warrants exercisable within 60 days of August 19, 2026.

On August 3, 2026, Mr. Klemp invested personal funds in a public offering, purchasing 533,333 shares and Series I warrants to purchase up to 1,599,999 shares at a combined price of $0.75 per share plus three warrants, for an aggregate of about $399,999.75. The warrants are exercisable at $0.75 per share until August 3, 2031, subject to a beneficial ownership limitation that Mr. Klemp elected to increase from 4.99% to 9.99% effective October 18, 2026, and include anti-dilution and Black Scholes-based provisions in certain transactions.

Moleculin Biotech, Inc. (MBRX) is asking stockholders to vote at the October 9, 2026 in‑person annual meeting in Houston. Proposals include electing five directors, ratifying the independent auditor, and a non‑binding advisory vote to approve executive compensation.

Stockholders are also asked to approve an amendment to the 2024 Equity Incentive Plan to increase shares authorized, an amendment to the Amended and Restated Certificate of Incorporation to eliminate supermajority voting requirements for future charter amendments, and an amendment granting the Board authority, in its sole discretion, to implement a reverse stock split at a ratio between 1‑for‑2 and 1‑for‑20 prior to the one‑year anniversary of the meeting. Another proposal would authorize adjournment of the meeting to solicit additional proxies if needed.

Record date was August 19, 2026, with 19,477,380 common shares outstanding, each entitled to one vote. The proxy describes governance structure, committee independence, detailed director and executive biographies, significant equity‑based compensation, and ownership, including the CEO’s 9.87% and a 9.9% institutional holder subject to warrant beneficial ownership limits.

Moleculin Biotech, Inc. (MBRX) is increasing the capacity of its existing at-the-market common stock program under its At The Market Offering Agreement with Roth Capital Partners to allow sales of up to $19,700,000 of common stock from and after August 21, 2026, not including shares previously sold. This supplements earlier ATM capacities of $6,500,000 set in July 2025 and $8,200,000 set in December 2025. As of this supplement, Moleculin has sold 486,775 shares for aggregate gross sales of $1,890,241 under the ATM program. The company’s common stock trades on the Nasdaq Capital Market under the symbol MBRX, with a last reported sale price of $0.5906 per share on August 20, 2026. Public float is approximately $64,852,256 based on 19,477,380 outstanding shares, of which 1,311,482 are held by affiliates, and Moleculin states it is subject to the one‑third public float limit for primary offerings under General Instruction I.B.6 of Form S‑3.

Moleculin Biotech, Inc. plans to hold its 2026 annual stockholder meeting on October 9, 2026 at its Houston headquarters, with 19,477,380 common shares entitled to vote as of August 19, 2026. Stockholders will vote on electing five directors, ratifying the independent auditor, and approving an amendment to the 2024 Equity Incentive Plan to increase shares authorized for issuance.

Additional proposals include an advisory vote on executive compensation, eliminating supermajority voting requirements to amend the certificate of incorporation, authorizing the board to implement a reverse stock split at a ratio between 1‑for‑2 and 1‑for‑20 within one year, and potentially adjourning the meeting to solicit more proxies. The proxy details board composition and independence, committee structures, executive and director pay, ownership (directors and officers as a group hold 12.69% of outstanding shares), and equity plans, including performance-based restricted stock units that vest upon specified corporate milestones.

Moleculin Biotech reported second quarter 2026 results and updated progress on its pivotal Phase 2/3 MIRACLE trial of Annamycin in relapsed or refractory acute myeloid leukemia. Preliminary unblinded data from the first 45 patients in Part A showed complete remission rates at least three times greater than the control arm, with no evidence of cardiotoxicity reported to date. Enrollment is on track to reach 90 patients in September 2026, with an unblinded efficacy readout expected in the December 2026 to February 2027 timeframe and Part B initiation planned for the first half of 2027.

Research and development expenses for the quarter were $5.5 million, up from $3.6 million a year earlier, mainly driven by the MIRACLE trial. General and administrative expenses were approximately $2.1 million, flat year over year. The company reported a quarterly net loss of $7.6 million, or $1.40 per share. Cash and cash equivalents were $7.3 million as of June 30, 2026, and together with $9.3 million raised after quarter-end, management expects this to fund planned operations into the first quarter of 2027, while also noting that significant additional financing will be required to conduct clinical trials as described.

Moleculin Biotech is a clinical‑stage oncology company focused on Annamycin (naxtarubicin), a "next‑generation" anthracycline. It is running the pivotal Phase 2/3 MIRACLE trial in relapsed/refractory AML, where preliminary unblinded Part A data for 45 patients showed complete remission (CR) rates of 43% and 36% in the two Annamycin arms versus 12% for the control, and CRc rates of 50% and 57% versus 29%. Pooled data from five trials (n=90) showed no evidence of drug‑related cardiotoxicity despite high cumulative doses.

For the six months ended June 30, 2026, the company reported no revenue and a net loss of $20.5 million, with R&D of $10.8 million driven largely by MIRACLE. Cash and cash equivalents were $7.3 million against an accumulated deficit of $226.5 million, and management disclosed substantial doubt about its ability to continue as a going concern. Subsequent to quarter‑end, an August 2026 equity/warrant offering raised $9.3 million gross, which, together with existing cash, is expected to fund operations into the first quarter of 2027, but the company estimates it needs roughly $8 million more to support MIRACLE and operations into the second quarter of 2027.

CVI Investments, Inc. and Heights Capital Management, Inc. report beneficial ownership of Moleculin Biotech, Inc. common stock. They collectively report beneficial ownership of 1,863,377 Shares, representing 9.9% of the outstanding common stock. The position consists of 1,400,000 Shares and additional Shares issuable upon exercise of Warrants that are subject to a 9.99% beneficial ownership limitation. Heights Capital Management, Inc., as investment manager to CVI Investments, Inc., may be deemed to share voting and dispositive power over these Shares, while each reporting person disclaims beneficial ownership beyond its pecuniary interest.

Moleculin Biotech, Inc. is the subject of a Schedule 13G reporting the ownership of common stock by Mitchell P. Kopin, Daniel B. Asher and Intracoastal Capital LLC. As of the close of business on August 6, 2025, they may be deemed to beneficially own 973,927 shares of common stock, representing approximately 4.99% of the class. This total includes 203,720 shares held by Intracoastal and 770,207 shares issuable upon exercise of a warrant referred to as Intracoastal Warrant 2, all calculated against a base of 7,100,713 shares outstanding as of July 30, 2026 plus additional shares issued in connection with a Securities Purchase Agreement.

The filing describes prior ownership immediately following execution of the Securities Purchase Agreement on July 31, 2026, when the reporting persons may have been deemed to beneficially own 788,091 shares (about 9.99% of the common stock) including shares to be issued and shares issuable upon exercise of a warrant. Both Intracoastal Warrant 1 and Intracoastal Warrant 2 contain blocker provisions limiting exercisability so that beneficial ownership does not exceed 9.99% or 4.99%, respectively. Without these blocker provisions, the reporting persons may have been deemed to beneficially own up to 5,333,332 shares immediately following the agreement and 4,203,719 shares as of August 6, 2025. The filing states that they now report ownership of 5 percent or less of the class.