Form 4 Filing for Roberts Brandi

Brandi Roberts, Chief Financial Officer of Definium Therapeutics, Inc., acquired 125,000 common shares on September 14, 2026. These shares represent the third tranche of performance share units granted on June 2, 2025, and are subject to vesting based on continued employment through June 2, 2028. The acquisition is contingent upon achieving certain clinical and regulatory milestones. The reported shares include 918 shares acquired through the company's Employee Share Purchase Plan on August 17, 2026. Following this transaction, Roberts beneficially owns 397,905 common shares.