X0508 4 2025-04-02 0001645469 Monopar Therapeutics MNPR 0001727357 Tactic Pharma LLC C/O 598 ROCKEFELLER RD LAKE FOREST IL 60045 1 0001727334 Robinson Chandler 1000 SKOKIE BLVD SUITE 350 WILMETTE IL 60091 1 1 Chief Executive Officer 0001035909 Brown Michael J C/O 598 ROCKEFELLER RD LAKE FOREST IL 60045 1 Member of 10% Owner Group 0001727481 O'Halloran Thomas V. C/O 598 ROCKEFELLER RD LAKE FOREST IL 60045 1 Member of 10% Owner Group 0001727393 Mazar Andrew Paul C/O 598 ROCKEFELLER RD LAKE FOREST IL 60045 1 Member of 10% Owner Group 0 Common Stock 2025-04-02 4 S 0 33334 35 D 822255 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $35.00 to $35.86, inclusive. The reporting person undertakes to provide to Monopar Therapeutics Inc., any security holder of Monopar Therapeutics Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. This Form 4 is being filed on behalf of Tactic Pharma LLC, an Illinois limited liability company ("Tactic"), and its managers, Andrew P. Mazar, Chandler D. Robinson, Michael J. Brown, and Thomas V. O'Halloran (collectively, the "Reporting Persons"). The managers collectively have voting control over the securities described herein. The managers each disclaim ownership of the shares of common stock owned by Tactic, except to the extent of their pecuniary interest therein. /s/ Chandler Robinson, Attorney-in-fact 2025-04-04