SEC Form 6-K filed by AC Immune SA

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR
15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of June 2026

Commission file number: 001-37891

AC IMMUNE SA

(Exact Name of Registrant as Specified in Its Charter)

EPFL Innovation Park
Building B
1015 Lausanne, Switzerland

(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or
Form 40-F.

Form 20-F ☒ Form 40-F ☐

On June 11, 2026, AC Immune SA (“AC Immune”) held its Annual General Meeting of Shareholders. The Management presentation to shareholders is attached hereto as Exhibit 99.1. The final results of all agenda items submitted to a vote of the shareholders are as below and the detailed results will be provided in the minutes which will be published on AC Immune’s website (https://ir.acimmune.com/governance) within 15 days:

Annual General Meeting Results

Agenda Item 1: 2025 IFRS Consolidated Financial Statements, 2025 Statutory Financial Statements, 2025 Compensation Report

Agenda Item 1.1: Approval of 2025 IFRS Consolidated Financial Statements and 2025 Statutory Financial Statements

AC Immune shareholders approved the 2025 IFRS Consolidated Financial Statements and the 2025 Statutory Financial Statements.

Agenda Item 1.2: Advisory Vote on the 2025 Compensation Report

AC Immune shareholders endorsed the 2025 Compensation Report.

Agenda Item 2: Appropriation of Losses

AC Immune shareholders approved that the net loss for the year 2025 in the amount of CHF 67,595K increases the “accumulated losses brought forward” of CHF 356,846K, resulting in a new balance of “accumulated losses brought forward” of CHF 424,441K.

Agenda Item 3: Discharge of the Members of the Board of Directors and the Executive Management

AC Immune shareholders approved the discharge of the Members of the Board of Directors and the Executive Management for the financial year 2025.

Agenda Item 4: Compensation for the Members of the Board of Directors and the Executive Management

Agenda Item 4.1: Binding Vote on Maximum Aggregate Compensation for Members of the Board of Directors from the AGM 2026 to the AGM 2027

AC Immune shareholders approved the total maximum amount of compensation for the Members of the Board of Directors of CHF 1,029K (excluding employer social security contributions) covering the period from the AGM 2026 to the AGM 2027.

Agenda Item 4.2: Binding Vote on Maximum Aggregate Compensation for Members of the Executive Management for the Financial Year 2027

AC Immune shareholders approved the total maximum amount of compensation for the Members of the Executive Management of CHF 6,742K (excluding employer social security contributions) from 1 January 2027 to 31 December 2027.

Agenda Item 5: Re-Elections

Agenda Item 5.1: Re-Elections of Members and the Chair of the Board of Directors

AC Immune shareholders approved the re-election of Renée Aguiar-Lucander, Monika Bütler, Carl June and Roy Twyman as Members of the Board of Directors and the re-election of Martin Zügel as Member and Chair of the Board of Directors, each until the end of the Annual General Meeting 2027.

Agenda Item 5.2: Re-Elections of Members of the Compensation, Nomination and Corporate Governance Committee

AC Immune shareholders approved the re-election of Monika Bütler and Roy Twyman as Members of the Compensation, Nomination and Corporate Governance Committee, each until the end of the Annual General Meeting 2027.

Agenda Item 5.3: Re-Election of the Statutory Auditors

AC Immune shareholders approved the re-election of PricewaterhouseCoopers SA, Lausanne, Switzerland, as AC Immune’s Statutory Auditors for the financial year 2026.

Agenda Item 5.4: Re-Election of the Independent Proxy

AC Immune shareholders approved the re-election of Reymond & Associés Attorneys, Lausanne, as AC Immune’s Independent Proxy until the end of the Annual General Meeting 2027.

Agenda Item 6: Changes in the Articles of Association

Agenda Item 6.1: Capital Band (Article 3a)

AC Immune shareholders approved the introduction of a capital band with an upper limit of CHF 2,862,500.00 and a lower limit of CHF 2,202,018.50, authorizing the Board to increase and/or decrease the Company’s share capital one or several times within these limits until 11 June 2031, and accordingly to amend Article 3a of the Articles of Association as set out in the Invitation to the Annual General Meeting.

Agenda Item 6.2: Increase of Conditional Share Capital for Employee-Benefit Plans (Article 3c)

AC Immune shareholders approved the increase of the conditional share capital for employee benefit plans from CHF 86,683.80 to CHF 150,000.00 and the amendment of Article 3c of the Articles of Association as set out in the Invitation to the Annual General Meeting.

This Report on Form 6-K shall be deemed to be incorporated by reference into the registration statements on Form F-3 (File Nos. 333-227016, 333-249655 and 333-277940) and Form S-8 (File Nos. 333-213865, 333-216539 and 333-233019) of AC Immune SA and to be a part thereof from the date on which this report is filed, to the extent not superseded by documents or reports subsequently filed or furnished.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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