Walter Klemp V - 20 Jun 2025 Form 4 Insider Report for Moleculin Biotech, Inc. (MBRX)

Role: CEO and President, Director
Signature: /s/ Jonathan P. Foster by Power of Attorney
Issuer symbol: MBRX
Transactions as of: 20 Jun 2025
Net transactions value: +$249,171
Form type: 4
Filing time: 23 Jun 2025, 16:35:11 UTC
Previous filing: 18 Jun 2025
Next filing: 13 Aug 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
KLEMP WALTER V	CEO and President, Director	C/O MOLECULIN BIOTECH, INC., 5300 MEMORIAL DR., SUITE 950, HOUSTON	/s/ Jonathan P. Foster by Power of Attorney	23 Jun 2025	0000938419

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MBRX	Common Stock	Options Exercise		+3,750	+6.4%		62,046	20 Jun 2025	Direct	F1
transaction	MBRX	Common Stock	Tax liability	$244	-914	-1.5%	$0.2670	61,132	20 Jun 2025	Direct	F2
transaction	MBRX	Common Stock	Options Exercise		+8,990	+15%		70,122	22 Jun 2025	Direct	F1
transaction	MBRX	Common Stock	Tax liability	$585	-2,190	-3.1%	$0.2670	67,932	22 Jun 2025	Direct	F2
transaction	MBRX	Common Stock	Purchase	$250,000	+675,675	+995%	$0.3700	743,607	23 Jun 2025	Direct	F5

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	MBRX	Restricted Stock Units	Options Exercise	$0	-3,750	-0.95%	$0.000000	391,446	20 Jun 2025	Common Stock	3,750		Direct	F1, F3
transaction	MBRX	Restricted Stock Units	Options Exercise	$0	-8,990	-2.3%	$0.000000	382,456	22 Jun 2025	Common Stock	8,990		Direct	F1, F4
transaction	MBRX	Series E Warrants	Purchase		-2,027,025	-46%		2,409,481	23 Jun 2025	Common Stock	2,027,025	$0.3700	Direct	F5

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Restricted stock units convert into common stock on a one-for-one basis.
F2	Shares withheld for payment of taxes upon vesting of restricted stock unit awards.
F3	On June 20, 2022, the reporting person was granted 15,000 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.
F4	On June 22, 2023, the reporting person was granted 35,959 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.
F5	On June 23, 2025, the reporting person acquired 675,675 shares of common stock and Series E warrants to purchase 2,027,025 shares of common stock at a purchase price of $0.37 per share and accompanying warrants in a public offering. The Series E warrants will be exercisable beginning on the effective date of stockholder approval of the issuance of the shares upon exercise of the Series E warrants and will expire five years from the date of such approval.