Daniel Karlin - 14 Sep 2026 Form 4 Insider Report for Definium Therapeutics, Inc. (DFTX)

Reporting relationship: Chief Medical Officer
Issuer ticker: DFTX
Reported as of: 14 Sep 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 14 Sep 2026, 08:30:09 UTC
Prior SEC filing: 12 Aug 2026
Source filing: View source filing
Reporting owner signature: /s/Mark Sullivan, Attorney-in-Fact for Dan Karlin

Key filing fact

Daniel Karlin filed Form 4 for Definium Therapeutics, Inc. (DFTX) on 14 Sep 2026.

Key facts

This page summarizes Daniel Karlin's Form 4 filing for Definium Therapeutics, Inc. (DFTX).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 14 Sep 2026, 08:30.

Change

Previous filing in this sequence was filed on 12 Aug 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001897618 Primary reporting owner

Karlin Daniel

Relationship: Chief Medical Officer
Address: C/O DEFINIUM THERAPEUTICS, INC., ONE WORLD TRADE CENTER, SUITE 8500, NEW YORK
Signature: /s/Mark Sullivan, Attorney-in-Fact for Dan Karlin
Signature date: 14 Sep 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

DFTX transaction

Common Shares

Award

Transaction value
Shares: +200,000
Change %: +33%
Price: $0.000000^*
Shares after: 803,699
Date: 14 Sep 2026
Ownership: Direct
Footnotes: F1, F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

The common shares represent the third tranche of performance share units granted effective March 12, 2025, and remain subject to vesting based on the Reporting Person's continued employment through March 12, 2028. Each performance share unit represented a contingent right to receive one common share based on, and subject to, the achievement of certain clinical and regulatory milestones set forth in the Performance Share Unit Award Agreement.

Footnote F2

Amount includes 417 shares acquired under the Definium Therapeutics, Inc. 2024 Employee Share Purchase Plan on August 17, 2026.