AC Immune Announces Amendment to Morphomer Tau License and Collaboration Agreement with Lilly Amended agreement reflects growing excitement in the field for targeting intracellular Tau and significant progr

AC Immune Announces Amendment to Morphomer

Tau License and Collaboration Agreement with Lilly

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 candidates and potential back-up

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.

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

and Morphomer , 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.

SupraAntigen is a registered trademark of AC Immune

SA in the following territories: AU, EU, CH, GB, JP, RU, SG and USA. Morphomer 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.

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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.