X0202 SCHEDULE 13D/A 0001884931 XXXXXXXX LIVE 4 Common Shares, without par value 04/24/2026 true 0001447028 03879J100 Arbutus Biopharma Corp

701 VETERANS CIRCLE WARMINSTER PA 18974

DAVID SALANIC 212-259-4370 WHITEFORT CAPITAL MANAGEMENT, LP 12 East 49th Street, 40th Floor New York NY 10017 JOSEPH KAPLAN 212-259-4370 WHITEFORT CAPITAL MANAGEMENT, LP 12 East 49th Street, 40th Floor New York NY 10017 RYAN NEBEL 212-451-2300 OLSHAN FROME WOLOSKY LLP 1325 Avenue of the Americas New York NY 10019 PATRICIA OLASKER 416-863-0900 DAVIES WARD PHILLIPS & VINEBERG LLP 155 Wellington Street West Toronto A6 M5V 3J7 0001704387 N Whitefort Capital Master Fund, LP WC N E9 0.00 15794261.00 0.00 15794261.00 15794261.00 N 8.0 PN Y Whitefort Capital GP, LLC AF N DE 0.00 15794261.00 0.00 15794261.00 15794261.00 N 8.0 OO 0001884931 N Whitefort Capital Management, LP AF N DE 0.00 15794261.00 0.00 15794261.00 15794261.00 N 8.0 IA PN Y Whitefort Capital Management GP, LLC AF N DE 0.00 15794261.00 0.00 15794261.00 15794261.00 N 8.0 OO Y David Salanic AF N I0 0.00 15794261.00 0.00 15794261.00 15794261.00 N 8.0 IN HC Y Joseph Kaplan AF N X1 0.00 15794261.00 0.00 15794261.00 15794261.00 N 8.0 IN HC Common Shares, without par value Arbutus Biopharma Corp 701 VETERANS CIRCLE WARMINSTER PA 18974 Item 3 is hereby amended and restated to read as follows: The securities of the Issuer purchased by Whitefort Master Fund were purchased with working capital (which may, at any given time, include margin loans made by brokerage firms in the ordinary course of business). The aggregate purchase price of the 15,794,261 Shares owned directly by Whitefort Master Fund is approximately $41,324,734, including brokerage commissions. Item 5(a) is hereby amended and restated to read as follows: The aggregate percentage of Shares reported owned by each person named herein is based upon 196,939,679 Shares outstanding as of March 30, 2026, which is the total number of Shares outstanding as reported in the Issuer's definitive proxy statement on Schedule 14A filed with the Securities and Exchange Commission on April 14, 2026. As of the date hereof, Whitefort Master Fund beneficially owns 15,794,261 Shares, constituting approximately 8.0% of the Shares outstanding. Whitefort Master GP, as the general partner of Whitefort Master Fund, may be deemed to beneficially own the 15,794,261 Shares owned by Whitefort Master Fund, constituting approximately 8.0% of the Shares outstanding. Whitefort Management, as the investment manager of Whitefort Master Fund, may be deemed to beneficially own the 15,794,261 Shares owned by Whitefort Master Fund, constituting approximately 8.0% of the Shares outstanding. Whitefort GP, as the general partner of Whitefort Management, may be deemed to beneficially own the 15,794,261 Shares owned by Whitefort Master Fund, constituting approximately 8.0% of the Shares outstanding. Each of Messrs. Salanic and Kaplan, as a Co-Managing Partner of Whitefort Management and a Co-Managing Member of each of Whitefort Master GP and Whitefort GP, may be deemed to beneficially own the 15,794,261 Shares owned by Whitefort Master Fund, constituting approximately 8.0% of the Shares outstanding. The filing of this Schedule 13D shall not be deemed an admission that the Reporting Persons are, for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, the beneficial owners of any securities of the Issuer he or it does not directly own. Each of the Reporting Persons specifically disclaims beneficial ownership of the securities reported herein that he or it does not directly own. Item 5(c) is hereby amended and restated to read as follows: The transactions in securities of the Issuer by the Reporting Persons since the filing of Amendment No. 3 by the Reporting Persons are set forth in Exhibit 1 and are incorporated herein by reference. Except for the swap transaction on April 27, 2026, the counterparty of which was Nomura Global Financial Products Inc. ("Nomura"), and the sale of Shares on the same date, all of such transactions were effected in the open market. Item 6 is hereby amended to add the following: Whitefort Master Fund has entered into a certain cash-settled total return swap agreement with Nomura as the counterparty (the "Swap Agreement"). Whitefort Master Fund's swap with Nomura constitutes economic exposure to an aggregate of 3,500,000 notional Shares, representing approximately 1.8% of the outstanding Shares, and has a maturity date of October 29, 2029 and a reference price of $4.2800. The Swap Agreement provides Whitefort Master Fund with economic results that are comparable to the economic results of ownership but does not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the Shares that are the subject of the Swap Agreement (such shares, the "Subject Shares"). Taking into account the Subject Shares, Whitefort Master Fund has economic exposure to an aggregate of 19,294,261 Shares, representing approximately 9.8% of the outstanding Shares. The Reporting Persons disclaim beneficial ownership of the Subject Shares. Item 7 is hereby amended to add the following exhibit: 1 - Transactions in Securities. Whitefort Capital Master Fund, LP /s/ David Salanic 04/28/2026 /s/ Joseph Kaplan 04/28/2026 Whitefort Capital GP, LLC /s/ David Salanic 04/28/2026 /s/ Joseph Kaplan 04/28/2026 Whitefort Capital Management, LP /s/ David Salanic 04/28/2026 /s/ Joseph Kaplan 04/28/2026 Whitefort Capital Management GP, LLC /s/ David Salanic 04/28/2026 /s/ Joseph Kaplan 04/28/2026 David Salanic /s/ David Salanic 04/28/2026 Joseph Kaplan /s/ Joseph Kaplan 04/28/2026