# EDGAR Filing Document

**Accession Number:** 0001651625
**File Stem:** 0000950103-26-005409
**Filing Date:** 2026-4
**Character Count:** 9636
**Document Hash:** d29eb3ae4e45545bf67faaed3bed9a6d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000950103-26-005409.hdr.sgml**: 20260407

**ACCESSION NUMBER**: 0000950103-26-005409

**CONFORMED SUBMISSION TYPE**: 6-K

**PUBLIC DOCUMENT COUNT**: 3

**CONFORMED PERIOD OF REPORT**: 20260402

**FILED AS OF DATE**: 20260407

**DATE AS OF CHANGE**: 20260407

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** AC Immune SA
- **CENTRAL INDEX KEY:** 0001651625
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** V8
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 6-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-37891
- **FILM NUMBER:** 26842926

**BUSINESS ADDRESS:**
- **STREET 1:** EPFL INNOVATION PARK, BUILDING B
- **CITY:** 1015 LAUSANNE
- **STATE:** V8
- **ZIP:** 00000
- **BUSINESS PHONE:** 41 21 345 91 21

**MAIL ADDRESS:**
- **STREET 1:** EPFL INNOVATION PARK, BUILDING B
- **CITY:** 1015 LAUSANNE
- **STATE:** V8
- **ZIP:** 00000

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 April 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 April 7, 2026, AC Immune SA ("AC Immune") issued a press release announcing an agreement with Eli Lilly and Company to amend their license and collaboration agreement dated as of December 11, 2018, as amended (the "License Agreement"), to research and develop Tau aggregation inhibitor small molecules for the potential treatment of Alzheimer's disease and other neurodegenerative diseases (the "Amendment").

Pursuant to the Amendment, AC Immune will receive a CHF 10 million upfront payment and a subsequent milestone payment with Phase 1 dosing, in addition to milestones announced in a prior amendment to the License Agreement dated as of March 20, 2020. AC Immune is eligible for further development, regulatory and commercial milestones of over CHF 1.7 billion, plus tiered percentage royalty payments in the low double digits, as previously disclosed. A copy of the press release is attached as Exhibit 99.1 to this Report on Form 6-K.

The descriptions of the Amendment in this Report on Form 6-K and in the accompanying Exhibit 99.1 are not complete and are qualified in their entirety by reference to the full text of such Amendment, a copy of which will be filed as an exhibit to a future filing by AC Immune with the U.S. Securities and Exchange Commission.

**EXHIBIT INDEX**

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| | |
|:---|:---|
| **Exhibit<br> Number** | **Description** |
| [99.1](dp244548_ex9901.htm) | [Press Release, dated April 7, 2026](dp244548_ex9901.htm) |

---

**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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| | | |
|:---|:---|:---|
|  | **AC IMMUNE SA** | **AC IMMUNE SA** |
|  | By: | /s/ Andrea Pfeifer |
|  | By: | Name: Andrea Pfeifer<br>Title: Chief Executive Officer<br>/s/ Christopher Roberts |
|  |  | Name: Christopher Roberts |
|  |  | Title: Chief Financial Officer |
| Date: April 7, 2026 |  |  |

---

## Exhibit 99.1

**Exhibit 99.1**

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| | |
|:---|:---|
| ![](image_001.jpg) | <br>**PRESS RELEASE**<br>|

---

**AC Immune Announces Amendment to Morphomer** <sup>®</sup> **Tau License and Collaboration Agreement with Lilly**

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· Amended agreement reflects growing excitement in the field for targeting
intracellular Tau and significant progress made with our Morphomer small molecules

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· Investigational New Drug (IND)-enabling studies to commence in H1 2026

**Lausanne, Switzerland, April 7, 2026 --** AC Immune SA (NASDAQ: ACIU), a clinical-stage biopharmaceutical company pioneering precision therapeutics for neurodegenerative diseases, today announced an agreement with Eli Lilly and Company (Lilly) to amend their 2018 license and collaboration agreement to research and develop Tau aggregation inhibitor small molecules for the potential treatment of Alzheimer's disease (AD) and other neurodegenerative diseases. The amendment continues the research and collaboration to cover development of new lead Tau Morphomer<sup>®</sup> candidates and potential back-up compounds.

**Dr. Andrea Pfeifer, CEO of AC Immune SA, commented:** "The progress in this collaboration highlights the important breakthroughs we have made with Morphomer small molecules for intracellular targeting of Tau. We look forward to working with the team at Lilly to drive forward the development of these potentially disruptive small molecule therapeutics for early-stage treatment and long-term prevention of neurodegenerative diseases. Increasingly, the scientific evidence suggests that targeting intracellular Tau can slow or even completely halt the pathology. This collaboration exemplifies our work towards precision prevention of neurodegenerative diseases. We expect to initiate Investigational New Drug (IND)-enabling studies imminently."

Morphomer Tau candidates were selected for their ability to enter the brain when dosed orally, and for their specific binding to the targeted pathological conformation of the Tau protein. AC Immune has generated strong preclinical data suggesting that Tau Morphomers should be clinically relevant for inhibiting aggregation and seeding across pathological and disease stages.

Under this amendment, AC Immune will receive a CHF10 million upfront payment and a subsequent milestone payment with Phase 1 dosing, in addition to milestones announced in a prior amendment. AC Immune is eligible for further development, regulatory and commercial milestones of over CHF1.7 billion, plus tiered percentage royalty payments in the low double digits, as previously disclosed.

**About AC Immune SA** 

AC Immune SA is a clinical-stage biopharmaceutical company and a global leader in precision prevention for neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and NeuroOrphan indications driven by misfolded proteins. The Company's two clinically validated technology platforms, SupraAntigen<sup>®</sup> and Morphomer<sup>®</sup>, fuel its pipeline of first- and best-in-class assets, which currently features a range of therapeutic and diagnostic programs, including candidates in Phase 2 and Phase 3 development. AC Immune has a strong track record of securing strategic partnerships with leading global pharmaceutical companies, resulting in substantial non-dilutive funding to advance its proprietary programs and >$4.5 billion in potential milestone payments plus royalties.

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| | |
|:---|:---|
| ![](image_001.jpg) | <br>**PRESS RELEASE**<br>|

---

SupraAntigen<sup>®</sup> is a registered trademark of AC Immune SA in the following territories: AU, EU, CH, GB, JP, RU, SG and USA. Morphomer<sup>®</sup> is a registered trademark of AC Immune SA in CA, CN, CH, EU, GB, JP, KR, NO, RU and SG.

The information on our website and any other websites referenced herein is expressly not incorporated by reference into, and does not constitute a part of, this press release.

**For further information, please contact:**

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| |
|:---|
| **SVP, Investor Relations & Corporate Communications<br>** <br> Gary Waanders, Ph.D., MBA<br> AC Immune<br> Phone: +41 21 345 91 91<br> Email: gary.waanders@acimmune.com**<br>**  |
| **International Media<br>** <br> Chris Maggos<br> Cohesion Bureau<br> Phone: +41 79 367 6254<br> Email: chris.maggos@cohesionbureau.com |

---

**Forward looking statements**

This press release contains statements that constitute "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Forward-looking statements are statements other than historical fact and may include statements that address future operating, financial or business performance or AC Immune's strategies or expectations. In some cases, you can identify these statements by forward-looking words such as "may," "might," "will," "should," "expects," "plans," "anticipates," "believes," "estimates," "predicts," "projects," "potential," "outlook" or "continue," and other comparable terminology. Forward-looking statements are based on management's current expectations and beliefs and involve significant risks and uncertainties that could cause actual results, developments and business decisions to differ materially from those contemplated by these statements. These risks and uncertainties include those described under the captions "Item 3. Key Information – Risk Factors" and "Item 5. Operating and Financial Review and Prospects" in AC Immune's Annual Report on Form 20-F and other filings with the Securities and Exchange Commission. Forward-looking statements speak only as of the date they are made, and AC Immune does not undertake any obligation to update them in light of new information, future developments or otherwise, except as may be required under applicable law. All forward-looking statements are qualified in their entirety by this cautionary statement.