MBRX · Moleculin Biotech, Inc.

Restricted stock units convert into common stock on a one-for-one basis.

Restricted stock units convert into common stock on a one-for-one basis.

On June 22, 2023, the reporting person was granted 1,439 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Includes 250,002 shares of common stock underlying Series E warrants to purchase common stock.

Restricted stock units convert into common stock on a one-for-one basis.

On June 22, 2023, the reporting person was granted 693 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Includes 100,003 shares of common stock underlying Series E warrants to purchase common stock.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Restricted stock units convert into common stock on a one-for-one basis.

On June 22, 2023, the reporting person was granted 283 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Restricted stock units convert into common stock on a one-for-one basis.

Restricted stock units convert into common stock on a one-for-one basis.

Restricted stock units convert into common stock on a one-for-one basis.

On June 20, 2022, the reporting person was granted 434 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Includes 100,003 shares of common stock underlying Series E warrants to purchase common stock.

Restricted stock units convert into common stock on a one-for-one basis.

On June 20, 2022, the reporting person was granted 600 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Includes 250,002 shares of common stock underlying Series E warrants to purchase common stock.

Restricted stock units convert into common stock on a one-for-one basis.

Restricted stock units convert into common stock on a one-for-one basis.

Restricted stock units convert into common stock on a one-for-one basis.

On June 20, 2022, the reporting person was granted 173 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Restricted stock units convert into common stock on a one-for-one basis.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

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

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

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.

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

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

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.

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

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.

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

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

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.

The options were issued in connection with the reporting person's Board of Director service to the Company.

The options set forth in this table vest on November 12, 2026, subject to the grantee's continued service on the Company's Board of Directors on each vesting date.

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

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.

The options were issued in connection with the reporting person's Board of Director service to the Company.

The options set forth in this table vest on November 12, 2026, subject to the grantee's continued service on the Company's Board of Directors on each vesting date.

The options were issued in connection with the reporting person's Board of Director service to the Company.

The options set forth in this table vest on November 12, 2026, subject to the grantee's continued service on the Company's Board of Directors on each vesting date.

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

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.

The options were issued in connection with the reporting person's Board of Director service to the Company.

The options set forth in this table vest on November 12, 2026, subject to the grantee's continued service on the Company's Board of Directors on each vesting date.

The options were issued in connection with the reporting person's Board of Director service to the Company.

The options set forth in this table vest on November 12, 2026, subject to the grantee's continued service on the Company's Board of Directors on each vesting date.

Restricted stock units convert into common stock on a one-for-one basis.

On November 4, 2024, the reporting person was granted 115,000 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Restricted stock units convert into common stock on a one-for-one basis.

Restricted stock units convert into common stock on a one-for-one basis.

On November 4, 2024, the reporting person was granted 35,000 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date

Restricted stock units convert into common stock on a one-for-one basis.

On November 4, 2024, the reporting person was granted 82,500 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Restricted stock units convert into common stock on a one-for-one basis.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Restricted stock units convert into common stock on a one-for-one basis.

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.

On June 23, 2025, the reporting person acquired 270,270 shares of common stock and Series E warrants to purchase 810,810 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.

On June 23, 2025, the reporting person acquired 270,270 shares of common stock and Series E warrants to purchase 810,810 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.

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.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Restricted stock units convert into common stock on a one-for-one basis.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Shares withheld for payment of taxes upon vesting of restricted stock unit awards.

Restricted stock units convert into common stock on a one-for-one basis.

On June 22, 2023, the reporting person was granted 7,063 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Restricted stock units convert into common stock on a one-for-one basis.

On June 22, 2023, the reporting person was granted 17,313 restricted stock units, vesting in four equal annual installments beginning on the first anniversary of the grant date.

Restricted stock units convert into common stock on a one-for-one basis.

Restricted stock units convert into common stock on a one-for-one basis.

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.