AC Immune Presents New Data on Alpha Synuclein PET Tracer at AD Pdtm Conference

Lausanne, Switzerland, March 29, 2019- AC Immune SA (NASDAQ: ACIU), a Swiss-based, clinical-stage biopharmaceutical company with a broad pipeline focused on neurodegenerative diseases, today announced new data on its positron-emission tomography (PET) tracer, which demonstrated a high-affinity binding to human Parkinson's disease-brain derived alpha-synuclein (a-syn), potentially capable of accurately detecting and monitoring progression of Parkinson's disease (PD) in humans.

The data, presented by AC Immune's Francesca Capotosti at the 14thInternational Conference on Alzheimer's and Parkinson's Diseases (AD/PDTM), taking place March 26 - 31 in Lisbon, demonstrated that AC Immune's small molecule Morphomer a-synTMPET tracer exhibits excellent selectivity towards human PD-brain derived a-syn, and a PK profile in non-human primates suitable for development as a PET tracer to detect and monitor progression of PD in humans.

Prof. Andrea Pfeifer, Ph.D., CEO of AC Immune SA, commented: "These data show the potential for what may be the first PET tracer for PD, which we are now moving into a Phase 1 trial. Along with our transformative deal with Lilly in December on small molecule Morphomer TauTMinhibitors, this program further validates our MorphomerTMplatform and illustrates AC Immune's leadership in precision medicine. We believe that therapeutic developments coupled with the diagnostic tools needed to properly identify and select patients allow us to follow disease progression and confirm potential efficacy of therapeutic interventions. This will provide critical differentiation for our product-candidates and benefit patients with neurodegenerative diseases."

The Morphomer a-syn PET tracer, which is entering clinical trials for the imaging of pathological a-syn in Parkinson's disease (PD) and other synucleinopathies, was derived from AC Immune's proprietary small molecule Morphomer discovery platform. The company also is beginning preclinical development of oral small moleculeMorphomer a-syn inhibitors and SupraAntigenTMa-syn antibodiesas novel therapeutic candidates to treat PD and a-syn-related NeuroOrphan diseases.

Development of a selective a-syn PET tracer would allow for earlier diagnosis and disease tracking. And it could transform drug development, offering an objective and efficient outcome measure to evaluate disease-modifying therapies, which remain the greatest unmet need of the millions living with Parkinson's disease.

The Morphomer discovery platform has recently been validated by aglobal partnership agreement with Eli Lilly for small molecule Tau Morphomer(TM)to treat Alzheimer's disease (AD) and other Tau-related neurodegenerative diseases. Importantly, under the deal valued at a potential $1.8 billion, AC Immune retained certain rights to develop Tau Morphomers in NeuroOrphan diseases, which allow accelerated clinical and streamlined regulatory development.

Progressive accumulation of aggregated a-syn in the form of Lewy bodies and neurites is the pathognomonic hallmark of PD. AC Immune is developing PET tracers as tools to study the distribution of aggregated a-syn in the living human brain. Due to the low density of a-syn pathology and the frequency of co-existing proteinopathies in PD (e.g., Abeta, Tau), an a-syn PET tracer must display high binding affinity to a-syn aggregates and high selectivity over other proteinaceous deposits, as well as minimal non-specific binding in order to be accurate.

AC Immune's Morphomer platform enables identification of a new class of low molecular weight compounds via rational chemical design that enables generation of small molecules, called Morphomers, which bind with high specificity to misfolded proteins, working to break up neurotoxic aggregates and inhibit aggregation and seeding. Other key CNS drug features of Morphomers include brain penetration, bioavailability and metabolic stability.

The PET tracer data was one of several presentations by AC Immune and its partners at AD/PD. These included:

• Determination of the optimal scanning time for the assessment of Tau deposition in Alzheimer's disease using PI-2620 PET

• Small molecules targeting Tau propagation demonstrate efficacy in an aggressive tauopathy mouse model

• Discovery and development of diagnostics and therapeutics for TDP-43 proteinopathies

• Determination of the optimal scanning time for the assessment of Tau deposition in Alzheimer's Disease using PI-2620 PET

• 18F-PI-2620 Tau-PET in progressive supranuclear palsy - a multi-center evaluation

• Evaluation of Tau deposition in amyloid positive MCI or mild-AD dementia subjects from the elenbecestat MissionAD program using18F-PI-2620 PET

About AC ImmuneAC Immune SA is a Nasdaq-listed clinical-stage biopharmaceutical company, which aims to become a global leader in precision medicine for neuro-degenerative diseases. The Company is utilizing two proprietary drug discovery platforms, SupraAntigenTMand MorphomerTM, to design, discover and develop small molecule and biological therapeutics as well as diagnostic products intended to prevent and modify neurodegenerative diseases caused by misfolding proteins. The Company's pipeline features nine therapeutic and three diagnostic product candidates, with five currently in clinical trials. It has collaborations with major pharmaceutical companies including Roche/Genentech, Lilly, Biogen, Janssen Pharmaceuticals, Nestlé Institute of Health Sciences, Life Molecular Imaging (formerly Piramal Imaging) and Essex Bio-Technology.

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