ACI-35.030

AC Immune’s PI-2620 Tau-PET Diagnostic in Phase 3 Receives Fast Track Designation in Three Neurodegenerative Conditions PI-2620 is in Phase 3 development in Alzheimer’s disease by AC Immune’s partner, LMIThis Fast Track designation applies across Alzheimer’s disease, progressive supranuclear palsy, and corticobasal degenerationFollows two previous Fast Track designations for ACI-35.030 and ACI-24.060 active immunotherapiesAffirms AC Immune’s leadership and commitment to bringing precision medicine to the management of neurodegenerative diseases Lausanne, Switzerland, August 28, 2024 – AC Immune SA (NASDAQ: ACIU), a clinical-stage biopharmaceutical company pioneering precision therapeutics for neurodegenerative diseases, today announced that its partner Life Molecular Imaging (LMI) has received Fast Track Designation for the Tau positron emission tomography (PET) diagnostic, [18F]PI-2620, from the U.S. Food and Drug Administration (FDA) in three neurodegenerative conditions. Fast Track designation for [18F]PI-2620 has been granted for clinical development in Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). The FDA’s Fast Track program is designed to accelerate the development and review of drugs that address serious conditions and fulfill unmet medical needs. This designation underscores the broadening view in the medical community that early and accurate diagnoses of neurodegenerative disease may lead to improved outcomes, thanks to emerging treatments. PI-2620 is a next-generation PET imaging agent currently in Phase 3 clinical development for detecting Tau pathology in Alzheimer's disease. The compound is also being investigated in other neurodegenerative diseases by many academic researchers and in drug development trials. Tau proteins are a hallmark of several neurodegenerative disorders including AD, PSP, CBD, and frontotemporal lobar dementia (FTLD), and accurately imaging the pathology could significantly enhance disease diagnosis and improve patient care. Dr. Andrea Pfeifer, CEO of AC Immune SA, commented: “Fast Track designation for PI-2620 is an important reflection of its potential to accurately diagnose Alzheimer’s and other neurodegenerative diseases. Early diagnosis of these conditions will be key for effective treatment before irreversible damage occurs, and is an essential element in our goal of achieving precision prevention. The FDA has previously granted Fast Track status to two of our active immunotherapies in Phase 2 development, ACI-35.030 and ACI-24.060, which target phospho-Tau and Abeta, respectively. The designation for PI-2620 is a further recognition of AC Immune’s drug discovery and development platform and of how we, together with our partners, continue to drive innovation.” About PI-2620PI-2620 was discovered and developed as part of a research collaboration between AC Immune and LMI. LMI has the exclusive, worldwide license for research, development and commercialization of Tau-PET tracers generated within the discovery program. It has demonstrated robust brain uptake and fast wash-out in non-target regions, a broad imaging window between 30- and 90-minutes post-injection for AD, and excellent reproducibility between test and retest scans. The absence of significant off-target binding enables PI-2620 to detect and quantify early Tau deposition in the brain, a hallmark of neurodegenerative diseases. PI-2620 is currently under investigation in several clinical studies as a targeted radiopharmaceutical for the detection of Tau deposits in the human brain. PI-2620 also shows promise for non-AD tauopathies like progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). 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® and Morphomer®, fuel its broad and diversified pipeline of first- and best-in-class assets, which currently features sixteen therapeutic and diagnostic programs, including five in Phase 2 development and one in Phase 3. 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 CN, CH, GB, JP, KR, NO and RU. 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: SVP, Investor Relations & Corporate CommunicationsGary Waanders, Ph.D., MBAAC ImmunePhone: +41 21 345 91 91Email: gary.waanders@acimmune.comU.S. InvestorsCorey Davis, Ph.D.LifeSci AdvisorsPhone: +1 212 915 2577 Email: cdavis@lifesciadvisors.comInternational MediaChris MaggosCohesion BureauPhone: +41 79 367 6254Email: chris.maggos@cohesionbureau.com Forward looking statementsThis 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. Attachment 20240828_ACIU_PI-2620 FastTrack_Final_CLEAN

AC Immune’s ACI-35.030 (now “JNJ-2056”) Granted FDA Fast Track Designation for Alzheimer’s Disease Treatment of first randomized person with preclinical AD expected this quarterPhase 2b ReTain trial is fully funded and conducted by development partner Lausanne, Switzerland, July 25, 2024 – AC Immune SA (NASDAQ: ACIU), a clinical-stage biopharmaceutical company pioneering precision medicine for neurodegenerative diseases, today announced that its active-immunotherapy candidate, ACI-35.030 (now called JNJ-2056), targeting the pathologic form of the Tau protein, phosphorylated Tau (pTau), has received Fast Track designation from the U.S. Food and Drug Administration (FDA). The recently initiated Phase 2b clinical trial ReTain is currently recruiting participants with preclinical Alzheimer’s disease, where individuals have yet to show clinical symptoms. Dr. Andrea Pfeifer, CEO of AC Immune SA, commented: “Fast Track designation is an important recognition of the differentiation and potential value for patients of our anti-pTau active immunotherapy, ACI-35.030. The Phase 2b ReTain study is the first time any active immunotherapy is being tested in a preclinical AD population. We believe this modality has the potential to offer therapeutic advantages, as well as benefits in terms of convenience and access. Fast Track designation offers opportunities for more efficient development and regulatory review. More importantly, this underscores and validates the potential therapeutic impact of an active immunotherapy specifically targeting pTau, the key pathologic species of Tau protein. In Phase 1b/2a clinical testing, ACI-35.030 was shown to specifically target this toxic form of Tau and spare normal endogenous forms of the protein. We and our partners continue to drive innovation in the treatment and potential prevention of Alzheimer’s disease, developing new mechanisms of action and first-in-class potential therapeutics that are safe and simple to use for the hundreds of millions of people living with or at risk of the disease.” JNJ-2056 is being developed pursuant to a global license, development and commercialization agreement with Janssen Pharmaceuticals, Inc. (Janssen), a Johnson & Johnson company. The ReTain trial is fully funded and conducted by Janssen. About the ReTain Trial The Phase 2b ReTain trial is a potentially registration-enabling randomized, multicenter, double-blind, placebo-controlled clinical study in participants with preclinical AD to assess the clinical effect of active immunization with JNJ-64042056. It is designed to test the hypothesis that JNJ-2056 has a disease-modifying effect that can delay or prevent the onset of cognitive impairment or other clinical symptoms in individuals with preclinical AD through inhibition of seeding and spreading of pathological Tau. The study will include approximately 500 participants with preclinical AD (cognitively normal, Tau positive), who will be randomized in a 1:1 ratio to a single dose level of JNJ-2056 or placebo and administered as intramuscular injections for a maximum of 4 years. The primary endpoint will measure cognitive decline as assessed by the Preclinical AD Cognitive Composite 5 (PACC-5) score. The key secondary efficacy endpoint will assess the effect of JNJ-2056 on the propagation and/or accumulation of Tau pathology compared with placebo, as measured by Tau PET imaging. About ACI-35.030 (JNJ-2056)ACI-35.030, derived from AC Immune’s SupraAntigen® platform, has been shown in clinical studies to induce a strong polyclonal antibody response that matures and is maintained against key pathological forms of Tau believed to drive Tau aggregation and disease progression. ACI-35.030 is designed to enhance the formation of broad-spectrum protective antibodies against pTau. This investigational candidate has the potential to reduce pathological Tau spreading in the early stages of AD, and thereby may reduce or prevent disease progression. About AC Immune SAAC Immune SA is a clinical-stage biopharmaceutical company and a global leader in precision medicine 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 broad and diversified pipeline of first- and best-in-class assets, which currently features sixteen therapeutic and diagnostic programs, five of which are currently in Phase 2 clinical trials and one of which is in Phase 3. AC Immune has a strong track record of securing strategic partnerships with leading global pharmaceutical companies, resulting in substantial non-dilutive funding 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 CN, CH, GB, JP, KR, NO and RU. 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: Head of Investor Relations & Corporate CommunicationsGary Waanders, Ph.D., MBAAC ImmunePhone: +41 21 345 91 91Email: gary.waanders@acimmune.comU.S. InvestorsCorey Davis, Ph.D.LifeSci AdvisorsPhone: +1 212 915 2577 Email: cdavis@lifesciadvisors.comInternational MediaChris MaggosCohesion BureauPhone: +41 79 367 6254Email: chris.maggos@cohesionbureau.com Forward looking statementsThis 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. These include: the impact of Covid-19 on our business, suppliers, patients and employees and any other impact of Covid-19. 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. Attachment 20240725_ACIU-ACI-35.030_FastTrack FINAL