Form 4 Filing for Mark Sullivan - Officer Sale of Common Shares

Mark Sullivan, Chief Legal Officer of Definium Therapeutics, Inc., reported a sale of 13,008 common shares on June 25, 2026. The shares were sold at a price of $45.03 per share, totaling $585,942.24. This transaction was conducted under a Rule 10b5-1 plan adopted on March 14, 2024, to cover withholding tax obligations associated with the settlement of vested restricted stock units. Following this transaction, Mr. Sullivan directly owns 320,571 common shares. The filing is Form 4, indicating a change in beneficial ownership.