Definium Therapeutics, Inc. (NASDAQ:DFTX) disclosed that its Chief Medical Officer, Daniel Karlin, sold 8,018 shares of common stock on March 25, 2026, according to a Form 4 filed with the Securities and Exchange Commission. The shares were disposed of at a weighted average price of $18.47, resulting in total proceeds of $148,092. Reported sale prices ranged between $18.36 and $18.80.
After the transaction, Karlin directly holds 413,317 shares of Definium Therapeutics common stock. That total includes 1,586 shares acquired through the Definium Therapeutics, Inc. 2024 Employee Share Purchase Plan.
The filing states the disposition was carried out to satisfy withholding tax obligations tied to the settlement of vested restricted stock units. The sale followed sell-to-cover elections made under a Rule 10b5-1 trading plan that Karlin adopted on June 14, 2022. The Form 4 was signed on Karlin's behalf by Mark Sullivan, Attorney-in-Fact, on March 26, 2026.
Company financial context
In related corporate disclosures, Definium Therapeutics reported its financial results for the fourth quarter of 2025. The company highlighted substantial investments in research and development during the quarter, with particular emphasis on its DT120 program.
Definium recorded a notable net loss for the period, though management noted the company continues to hold a strong cash position. The firm described that cash resources as supporting its clinical pipeline and strategic initiatives, enabling continued focus on advancing its research programs despite the quarterly loss.
Following the earnings release there was a modest increase in aftermarket trading activity, but commentary from the company and filings indicate the primary emphasis remains on R&D efforts and long-term program objectives. The company did not report any analyst upgrades or downgrades in connection with the earnings announcement.
What the filings confirm
- The exact share count sold by Karlin: 8,018 shares on March 25, 2026.
- Weighted average sale price: $18.47; total transaction value: $148,092; price range: $18.36 to $18.80.
- Post-sale direct ownership for Karlin: 413,317 shares, including 1,586 from the 2024 Employee Share Purchase Plan.
- Sale reason: satisfy withholding tax obligations from vesting restricted stock units under sell-to-cover elections within a Rule 10b5-1 plan adopted June 14, 2022. Form 4 signed March 26, 2026, by Mark Sullivan as Attorney-in-Fact.
The filings and financial disclosures together underscore the company's sustained commitment to funding research programs, particularly DT120, while executive stock movements tied to tax obligations have been executed under pre-existing plan mechanics.