Lausanne 19 May 2020 Invitation to the Ordinary Shareholders' Meeting Date: Friday, 26 June 2020 | 11:00 am Swiss time Place: R. Reagan Room | EPFL Innovation Park, Building B | Ecublens | Switzerland I. Letter to the Sh

Lausanne 19 May 2020

the Ordinary Shareholders' Meeting

Contact information: AC Immune SA, Investor Services, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland,

Tel: +41 21 345 91 22 | Email: agm@acimmune.com | Visit our Webpage: https://ir.acimmune.com/events/agm

I. Letter to the Shareholders

2019 has been an extraordinary year in the

field of Alzheimer's disease and for AC Immune, with multiple clinical, value-creating milestones achieved and continued

demonstration of our leadership in the field through the development and communication of our Roadmap to Successful Therapies

for Neurodegenerative Diseases.

Our continued strong cash position of CHF

277.9 million, as of 31 March 2020, funds the Company through Q1 2024 without potential milestones, and will ensure we remain a

leader in discovering and developing breakthrough therapies. This core financial stability and strength reflects that, as with

our research strategy, we have always taken a long-term, informed approach. As a result, we are in the best position possible to

manage the extraordinary situation presented by Covid-19 with our transformative industry partnerships an important element in

our continuing strong financial outlook.

Transformative collaborations

In 2019, our partnership with Eli Lilly

and Company on the small molecule Morphomer Tau aggregation inhibitor program has

gone from strength to strength, with CHF 110 million received in upfront and development milestone payments and a USD 50 million

equity note. This strong financial outlook continues in 2020, with a second CHF 10 million milestone payment received in Q1 and

our transformative agreement with Lilly expanded to add a new potential CHF 60 million Phase 2 initiation milestone. Our financial

position has been further strengthened with a milestone payment of EUR 2 million (CHF 2.2 million) from Life Molecular Imaging

in Q3 2019 in connection with the initiation of a Phase 2 study in our Tau-imaging program.

Pipeline advancement

With increasing recognition that precision

medicine is likely to be the best way to address the complexity of neurodegenerative disease pathology, one of AC Immune's

key strengths is our diversified approach. Through 2019, we are pleased to have advanced the nine therapeutic and three diagnostic

product candidates in the Company's pipeline. These advances include those on well-established targets like Tau and Abeta, as well

as novel targets and mechanisms.

The close correlation between the spread

of Tau pathology and the onset and progression of cognitive decline, increasingly underscores the importance of Tau-targeted therapies.

The Tau window of therapeutic intervention now seems much broader than Abeta and, as a result, may offer multiple opportunities

for mono- or combination therapies to disrupt, slow or prevent disease progression - both at early and later stages of the

disease. As such, Tau-targeted approaches are a key element of our Roadmap, and with partners, we are advancing one of the

industry's broadest Tau pipelines. In 2019 significant progress was achieved across our small molecule, antibody, vaccine

and diagnostic programs.

Contact information: AC Immune SA, Investor Services, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland,

Tel: +41 21 345 91 22 | Email: agm@acimmune.com | Visit our Webpage: https://ir.acimmune.com/events/agm

As we progress through 2020, we are building

on these successes with a number of clinical milestones anticipated across these programs including the first Phase 2 readout of

an anti-Tau antibody in Alzheimer's disease, in the semorinemab trial in prodromal to mild Alzheimer's disease. Phase

1 results are also anticipated in healthy volunteers for the ACI-3024 small molecule Morphomer Tau aggregation inhibitor.

Both milestones reflect we are at the cutting-edge of research. ACI-3024's unique mechanism

of action targets misfolded Tau proteins both inside and outside cells. While semorinemab offers the potential for a first-in-class

immunotherapy designed to intercept the cell-to-cell spread of pathological Tau.

In tandem, Abeta remains an important focus

of AC Immune's pipeline with clinical readouts in H2 2020 on both anti-Abeta vaccine programs in Alzheimer's disease

and Down syndrome-related Alzheimer's disease. Our Down syndrome program remains the most advanced in the world, with plans

being finalized to initiate a Phase 2 trial in H2 2020. This builds on initial interim data from the Phase 1b trial announced in

July 2019 that showed ACI-24 has a favorable safety profile at all doses tested, mirroring

previous clinical trial results.

AC Immune has always maintained a robust

business continuity plan. During the Covid-19 outbreak, every provision is being made to protect the health of patients, staff

and investigators, as well as the productivity and integrity of our clinical development. Importantly, we currently remain on track

to deliver the five clinical readouts expected in 2020, owing largely to the fact that many of the Company's key trials are

already fully enrolled, and patient follow up is continuing virtually. The potential impact of Covid-19 on the Company's

business and operations has been comprehensively assessed, and its status as of May 4, 2020, whilst not directly relevant for this

Annual General Meeting 2020 has been disclosed in our 6-K Form filed with the U.S. Security & Exchange Commission, the full

details can be read here:

There are positive signs that countries,

including Switzerland, are beginning to ease restrictions. AC Immune remains in continuous contact with its partners and other

important stakeholders, including the Swiss government, trial investigators and contractors. At this stage the Company is not modifying

guidance with respect to the multiple clinical and preclinical data readouts anticipated this year. AC Immune will keep the market

apprised of any new developments or information that may impact clinical timelines.

The strength of our clinical programs is

also mirrored in our preclinical programs. In Q1 2020, we achieved the first of five milestones, with the rest remaining on track.

Thanks to work undertaken through 2019, new

Contact information: AC Immune SA, Investor Services, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland,

Tel: +41 21 345 91 22 | Email: agm@acimmune.com | Visit our Webpage: https://ir.acimmune.com/events/agm

proof-of-concept data was presented at this

year's AAT-AD/PDTM on our TDP-43 and alpha-synuclein therapeutic and diagnostic programs. These pathological proteins

represent targets of increasing interest for the treatment of neurodegenerative diseases, including NeuroOrphan indications, and

AC Immune's programs are amongst the most advanced in the field. Our leadership in this area was further strengthened in

2019 through a new research collaboration on TDP-43 with leading scientists at the Perelman School of Medicine, University of Pennsylvania,

and a new grant from The Michael J. Fox Foundation for our pioneering alpha-synuclein PET tracer program.

Through 2019 we remained steadfast in our

leadership and approach as many others seeded doubt about the Abeta hypothesis. Recent developments in the field reflect, our continued

belief in Abeta, especially in preventative settings, was correct. Only through the continued commitment of you, our highly valued

shareholders, was this possible and we would like to take this opportunity to extend our gratitude for your continued interest

and engagement in our work in such an exciting and challenging field, which is one of the greatest unmet medical needs as well

as one of the biggest opportunities in healthcare.

This year Covid-19 represents a new challenge

- one we have risen to. The depth and breadth of our scientific knowledge and understanding has ensured that we have been

able to anticipate, activate and implement a robust business continuity plan. I am proud and humbled that we remain on track to

deliver multiple clinical and preclinical data readouts anticipated in 2020, backed by a strong financial position.

Contact information: AC Immune SA, Investor Services, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland,

Tel: +41 21 345 91 22 | Email: agm@acimmune.com | Visit our Webpage: https://ir.acimmune.com/events/agm

Kindly find hereafter the agenda items and proposals of the Board

of Directors in connection with the fourth ordinary annual meeting of AC Immune SA as a public company:

The Board of Directors

proposes to approve the Annual Report, the Annual Statutory Financial Statements and the Financial Statements under IFRS of AC

Immune SA for the year 2019, and to take note of the Reports of the Auditors. Copies of these documents are available for download

on the "Annual General Meeting 2020" page of the "Investors" section of our website at:

The Board of Directors proposes

that the profit for the year ended 31 December 2019 in the statutory financial statements of the Company of KCHF 45'169 reduces

the "accumulated losses brought forward" of KCHF 107'320, resulting in a new balance of "accumulated losses