SEC Form 3 · accession 0001193125-26-388120

Korsana Biosciences, Inc. · KRSA

Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗

Table I — non-derivative securities

Table II — derivative securities

Explanation of responses

• F1Effective as of September 8, 2026 (the "Effective Time"), (i) Cariboos Merger Sub Corp., a wholly owned subsidiary of Cyclerion Therapeutics, Inc. ("Cyclerion"), merged with and into Korsana Biosciences, Inc. ("Pre-Merger Korsana"), with Pre-Merger Korsana continuing as a wholly owned subsidiary of Cyclerion and the surviving corporation of the merger (the "First Merger"), and (ii) immediately thereafter, Pre-Merger Korsana merged with and into Cariboos Merger Sub II, LLC, a second wholly owned subsidiary of Cyclerion ("Second Merger Sub"), with Second Merger Sub being the surviving entity of the merger under the name Korsana Biosciences Operating Company, LLC (the "Second Merger" and, together with the First Merger, the "Merger"). At the Effective Time, Cyclerion changed its name to "Korsana Biosciences, Inc." (hereinafter, the "Issuer").
• F2Represents options to purchase shares of the Issuer's common stock received by the Reporting Person in the Merger in exchange for options of Pre-Merger Korsana held by the Reporting Person prior to the Merger. This option vests in 36 equal monthly installments following June 18, 2026, through June 18, 2029, subject to the Reporting Person's continued service to the Issuer on each such vesting date.

Remarks

Exhibit 24 - Power of Attorney