MBRX awards CEO 830,000 options and 750,000 performance RSUs

Rhea-AI Filing Summary

Moleculin Biotech (MBRX) disclosed insider equity awards to its CEO and President on 11/12/2025. The filing reports a stock option grant for 830,000 shares at an exercise price of $0.49, vesting in four equal annual installments beginning on the first anniversary of the grant, subject to continued service.

The CEO also received 750,000 performance-based restricted stock units, each representing one share. These RSUs vest in 20% increments upon achievement of specified clinical milestones, and 100% vest upon a change of control as defined in the 2024 Stock Plan. Following these awards, the form shows 3,960,731 derivative securities beneficially owned.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider KLEMP WALTER V

Role CEO and President

Type	Security	Shares	Price	Value
Grant/Award	Stock option (right to buy)	830,000	$0.00	--
Grant/Award	Performance Based Restricted Stock Units	750,000	$0.00	--

Holdings After Transaction: Stock option (right to buy) — 3,210,731 shares (Direct); Performance Based Restricted Stock Units — 3,960,731 shares (Direct)

Footnotes (1)

1. The stock option set forth in this table vests in four equal annual installments beginning on the first anniversary of the Transaction Date, subject to the grantee's continued service to the Company on each vesting date. Issued in connection with the reporting person's employment with the Company. Each restricted stock unit represents a contingent right to receive one shares of Company common stock. On November 12, 2025, the Board approved this performance based restricted stock unit. The performance based restricted stock units set forth in this table will vest in 20% installments upon the achievement of certain clinical milestones; provided that upon a change of control (as defined in the 2024 Stock Plan) 100% shall vest.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

KLEMP WALTER V

(Last) (First) (Middle)

C/O MOLECULIN BIOTECH, INC.

5300 MEMORIAL DR., SUITE 950

(Street)

HOUSTON TX 77007

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Moleculin Biotech, Inc. [ MBRX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CEO and President

3. Date of Earliest Transaction (Month/Day/Year)
11/12/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock option (right to buy)	$0.49	11/12/2025		A		830,000		(1)	11/12/2035	Common Stock	830,000	(2)	3,210,731	D
Performance Based Restricted Stock Units	(3)	11/12/2025		A		750,000		(4)	11/12/2035	Common Stock	750,000	(2)	3,960,731	D

Explanation of Responses:

1. The stock option set forth in this table vests in four equal annual installments beginning on the first anniversary of the Transaction Date, subject to the grantee's continued service to the Company on each vesting date.

2. Issued in connection with the reporting person's employment with the Company.

3. Each restricted stock unit represents a contingent right to receive one shares of Company common stock.

4. On November 12, 2025, the Board approved this performance based restricted stock unit. The performance based restricted stock units set forth in this table will vest in 20% installments upon the achievement of certain clinical milestones; provided that upon a change of control (as defined in the 2024 Stock Plan) 100% shall vest.

	/s/ Jonathan P. Foster by Power of Attorney	11/14/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Moleculin Biotech (MBRX) report in this Form 4?

An insider equity award to the CEO and President on 11/12/2025, including stock options and performance-based RSUs.

How many stock options were granted and at what price?

The filing lists 830,000 stock options with an exercise price of $0.49 per share.

What are the vesting terms for the stock options?

They vest in four equal annual installments beginning on the first anniversary of the grant, subject to continued service.

How many performance-based RSUs were granted and how do they vest?

The CEO received 750,000 performance-based RSUs that vest in 20% increments upon achievement of specified clinical milestones.

What happens to the RSUs upon a change of control?

100% of the RSUs vest upon a change of control as defined in the 2024 Stock Plan.

How many derivative securities are beneficially owned after these awards?

The form shows 3,960,731 derivative securities beneficially owned following the reported transactions.