Jonathan P. Foster - 03 Aug 2026 Form 4 Insider Report for Moleculin Biotech, Inc. (MBRX)

Reporting relationship: Chief Financial Officer
Issuer ticker: MBRX
Reported as of: 03 Aug 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 05 Aug 2026, 16:16:33 UTC
Prior SEC filing: 24 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Jonathan P. Foster

Key filing fact

Jonathan P. Foster filed Form 4 for Moleculin Biotech, Inc. (MBRX) on 05 Aug 2026.

Key facts

This page summarizes Jonathan P. Foster's Form 4 filing for Moleculin Biotech, Inc. (MBRX).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 05 Aug 2026, 16:16.

Change

Previous filing in this sequence was filed on 24 Jun 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001545414 Primary reporting owner

Foster Jonathan P.

Relationship: Chief Financial Officer
Address: C/O MOLECULIN BIOTECH, INC., 5300 MEMORIAL DR., SUITE 950, HOUSTON
Signature: /s/ Jonathan P. Foster
Signature date: 05 Aug 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

MBRX transaction

Common Stock

Purchase

Transaction value
Shares: +293,333
Change %: +2377%
Price
Shares after: 305,673
Date: 03 Aug 2026
Ownership: Direct
Footnotes: F1

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

MBRX transaction Derivative

Series I Warrants

Purchase

Transaction value
Shares: +879,999
Change %: +596%
Price
Shares after: 1,027,717
Date: 03 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 879,999
Exercise price
Footnotes: F1

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 1 footnote

Footnote F1

On August 3, 2026, the reporting person acquired 293,333 shares of common stock and Series I warrants to purchase 879,999 shares of common stock at a combined purchase price of $0.75 per one share of common stock and three accompanying warrants in a public offering.