{"success":true,"data":{"pressRelease":{"id":"150658","rtpr_id":"nGNX52qtkv-20260923","ticker":"ACIU","exchange":"NASDAQ","all_tickers":["ACIU"],"title":"AC Immune Reports Positive Safety & Immunogenicity at week-100 in Part 1 of VacSYn Phase 2 Trial of ACI-7104","author":"Globe Newswire","published_at":"2026-09-23T11:00:01.145Z","article_body":"* All primary endpoints of the study were met, with ACI-7104 shown to be\ngenerally safe and well tolerated \n* Strong immunogenicity demonstrated, with 100% response rate after three\nimmunizations\n* Clear antibody penetration into the cerebrospinal fluid (CSF) and signals\nfor target engagement \n* Discussions with FDA regarding future development path planned for early\n2027 \n* AC Immune to host webcast & conference call today at 10:00am EDT / 16:00\nCEST details below\nLausanne, Switzerland, September 23, 2026 – AC Immune SA (NASDAQ: ACIU), a\nclinical-stage biopharmaceutical company developing targeted therapeutics for\nneurodegenerative diseases, today announced positive safety and immunogenicity\nresults through week-100 in Part 1 of VacSYn, its randomized, double-blind,\nplacebo-controlled Phase 2 trial of ACI-7104 in patients with early-stage\nParkinson’s disease (PD). The study is being conducted in two parts with the\naim for Part 1 being to show safety, tolerability and immunogenicity while\nPart 2 is designed to provide evidence of clinical activity as the basis for a\nPhase 3 decision. The Part 1 data reported today includes results from all 34\npatients randomized into the study (25 patients receiving ACI-7104 and nine\nreceiving placebo).\n\nThe primary endpoints for Part 1 of the VacSYn trial of ACI-7104 were safety,\ntolerability and immunogenicity, all of which were met. ACI-7104 was generally\nsafe and well-tolerated and shown to be strongly immunogenic, with 100% of\npatients developing antibodies against the immunizing a-syn target antigen\nPD01 after three immunizations. Antibody reactivity against the aggregated\nspecies of a-syn was also demonstrated. Robust antibody penetration into the\ncerebrospinal fluid (CSF) was observed in all patients.\n\nPart 1 of VacSYn was not designed for biomarker or clinical outcomes\nevaluation; however, additional exploratory analyses included monitoring the\nimpact of ACI-7104 treatment on certain biomarkers (such as total a-syn and\nNeurofilament Light chain in the CSF), as well as clinical measures of disease\nactivity. A signal was observed for total a-syn in the CSF, providing\npreliminary evidence consistent with target engagement. Exploratory\ncorrelation analyses identified trends suggesting an association between\nimmunogenicity (antibody levels) and disease activity measures. While the\nsample size in Part 1 was limited, these observations provide a clear basis\nfor further investigation.\n\nThe VacSYn trial of ACI-7104 in early-stage Parkinson’s disease continues in\nPart 1 (2-year extension) and is advancing toward the initiation of Part 2\n(expansion). The final design of Part 2 is being consolidated and will be\nsubmitted to the FDA for review, with meetings expected early in 2027.\n\nMartin Zügel, Interim CEO of AC Immune SA, commented: “The results from\nthe complete data set at week-100 in Part 1 are encouraging, with all primary\nendpoints met, strong immunogenicity demonstrated, and a 100% response rate.\nThis program is one of our strongest active immunotherapies, with\nACI-7104-induced antibodies demonstrating preferential binding to aggregated\na-syn species. We will now refine our approach to the next development steps\nin the program and discuss our plans with regulators before embarking on an\nexpanded Phase 2 trial designed to provide evidence of clinical activity as\nthe basis for entry into Phase 3.”\n\nGünther Staffler, Executive Vice President, Development at AC Immune SA,\ncommented: “We are pleased to have observed strong and boostable immune\nresponses, with significant antibody penetration into the CSF and signals for\ntarget engagement. Together with the favorable safety profile through\nweek-100, and exploratory correlations between antibody titers and disease\nactivity measures, we are confident that these results provide a strong\nfoundation for the continued development of ACI-7104 into Part 2.”\n\nConference call details:\nParticipants may call the following numbers, 10 – 15 minutes before\nconference start\n\nSwitzerland / Europe:    +41 (0) 58 310 50 00\n\nUnited Kingdom:           +44 (0) 203 059 58 63\n\nUnited States:               +1 (1) 631 570 56 13\n\nHD Web Phone™:        Click Here\n\nOther international numbers available HERE\n\nWebcast link:\nhttps://event.choruscall.com/mediaframe/webcast.html?webcastid=lUHjSJWK\n\nA live and archived webcast will also be accessible in the Investors section\nof the Company's website at https://www.acimmune.com/.\n\nEnds\n\nFor further information, please contact:\n\n SVP, Investor Relations & Corporate Communications                                                \n \nGary Waanders, Ph.D., MBA AC Immune Phone: +41 21 345 91 91 Email: gary.waanders@acimmune.com    \n International Media  Optimum Strategic Communications                                             \n Nick Bastin, Joshua Evans, Aoife Minihan, Ben Cowe                                                \n Phone: +44 (0) 20 4566 8543 Email: acimmune@optimumcomms.com                                      \n                                                                                                   \n\nAbout VacSYn\n\nVacSYn (ClinicalTrials.gov: NCT06015841\n(https://www.globenewswire.com/Tracker?data=Bwj09Ke19Rq3D-XhcpmiKXHA60ExHxAVrm51uNLLzAEIZ6wlPvIfZ2PFaLUsNbZ6YdI1Py4ztOL7KowpQbmw82diEgp0wRxJ9hZn7IiCuCzjqZPXZKgYw5yTnTNdStN7JnIMaP5urLMIj3tZ957taOU3F6Y2_GLUjNH1AUazQM4=))\nis an adaptive, randomized, double-blind, placebo-controlled, and\nbiomarker-based Phase 2 study in patients with early PD, consisting of two\nparts. Part 1 includes 34 patients randomized 3:1 to receive ACI-7104 or\nplacebo, respectively. The results reported today include data from all\nparticipants 100 weeks since initiation of treatment. The study is being\nconducted in two parts with the aim for Part 1 being to show safety,\ntolerability and immunogenicity while Part 2 is designed to provide evidence\nof clinical activity and support a Phase 3 decision.\n\nAbout ACI-7104\n\nACI-7104.056 is an optimized formulation of its clinically validated\nanti-a-syn predecessor active immunotherapy that generated a target-specific\nantibody response against pathological oligomeric a-syn to inhibit spreading\nand downstream neurodegeneration in early Parkinson’s disease. The\naccumulation of alpha-synuclein protein aggregates has been shown to cause\ninflammatory stress in cells and contribute to the degeneration of neurons in\nthe brain. It has been known to play a key role in the development of\nneurodegenerative diseases such as Parkinson’s Disease.\n\nAbout AC Immune SA \n\nAC Immune (NASDAQ: ACIU) is a clinical-stage biopharmaceutical company\ndeveloping a pipeline of products, including both active immunotherapies and\nsmall molecules, targeting key misfolded proteins and pathways for the\ntreatment of multiple neurodegenerative diseases. The company has a growing\nfocus on its wholly owned proprietary clinical-stage programs, including:\nACI-7104, an active immunotherapy targeting α-synuclein (α-syn) in\nParkinson's disease; and ACI-19764, a small molecule inhibitor of the NLRP3\ninflammasome. In addition, an early-stage small molecule development program\ntargeting intracellular a-syn is advancing towards the clinic.\n\nACIU has a strong track record of securing strategic partnerships with leading\nglobal pharmaceutical companies, resulting in substantial non-dilutive funding\nand >$4.5 billion in potential milestone payments, plus royalties from sales.\nACIU’s pharma-partnered programs, all in Alzheimer’s disease, include: a\ncollaboration on ACI-24, an active immunotherapy targeting Abeta; a\ncollaboration on ACI-35 targeting phospho-Tau; and a collaboration developing\nbrain-penetrant small molecule drugs targeting intracellular pathologic Tau.\n\nAll trademarks used or mentioned in this release are protected by law. The\ninformation on our website and any other websites referenced herein is\nexpressly not incorporated by reference into, and does not constitute a part\nof, this press release.\n\nForward looking statements\n\nThis press release contains statements that constitute “forward-looking\nstatements” within the meaning of Section 27A of the Securities Act of 1933\nand Section 21E of the Securities Exchange Act of 1934. Forward-looking\nstatements are statements other than historical fact and may include\nstatements that address future operating, financial or business performance or\nAC Immune’s strategies or expectations. In some cases, you can identify\nthese statements by forward-looking words such as “may,” “might,”\n“will,” “should,” “expects,” “plans,” “anticipates,”\n“believes,” “estimates,” “predicts,” “projects,”\n“potential,” “outlook” or “continue,” and other comparable\nterminology. Forward-looking statements are based on management’s current\nexpectations and beliefs and involve significant risks and uncertainties that\ncould cause actual results, developments and business decisions to differ\nmaterially from those contemplated by these statements. These risks and\nuncertainties include those described under the captions “Item 3. Key\nInformation – Risk Factors” and “Item 5. Operating and Financial Review\nand Prospects” in AC Immune’s Annual Report on Form 20-F and other filings\nwith the Securities and Exchange Commission. Forward-looking statements speak\nonly as of the date they are made, and AC Immune does not undertake any\nobligation to update them in light of new information, future developments or\notherwise, except as may be required under applicable law. All forward-looking\nstatements are qualified in their entirety by this cautionary statement.\n\nAttachment\n*     FINAL__ACIU ACI-7104 Part 1 week 100 VacSYn Phase 2 results PR\n(https://ml-eu.globenewswire.com/Resource/Download/80ba5739-f9d7-4152-b1e0-756e1aa09395)\n(https://www.globenewswire.com/NewsRoom/AttachmentNg/0065cdfd-b9fc-4994-8aca-731c1d031b51)\n\n\n\nGlobeNewswire, Inc. 2026","article_body_html":"","raw_payload":{"data":{"id":"nGNX52qtkv-20260923","title":"AC Immune Reports Positive Safety & Immunogenicity at week-100 in Part 1 of VacSYn Phase 2 Trial of ACI-7104","author":"Globe Newswire","ticker":"ACIU","created":"2026-09-23T11:00:01.145Z","tickers":["ACIU"],"exchange":"NASDAQ","article_body":"* All primary endpoints of the study were met, with ACI-7104 shown to be\ngenerally safe and well tolerated \n* Strong immunogenicity demonstrated, with 100% response rate after three\nimmunizations\n* Clear antibody penetration into the cerebrospinal fluid (CSF) and signals\nfor target engagement \n* Discussions with FDA regarding future development path planned for early\n2027 \n* AC Immune to host webcast & conference call today at 10:00am EDT / 16:00\nCEST details below\nLausanne, Switzerland, September 23, 2026 – AC Immune SA (NASDAQ: ACIU), a\nclinical-stage biopharmaceutical company developing targeted therapeutics for\nneurodegenerative diseases, today announced positive safety and immunogenicity\nresults through week-100 in Part 1 of VacSYn, its randomized, double-blind,\nplacebo-controlled Phase 2 trial of ACI-7104 in patients with early-stage\nParkinson’s disease (PD). The study is being conducted in two parts with the\naim for Part 1 being to show safety, tolerability and immunogenicity while\nPart 2 is designed to provide evidence of clinical activity as the basis for a\nPhase 3 decision. The Part 1 data reported today includes results from all 34\npatients randomized into the study (25 patients receiving ACI-7104 and nine\nreceiving placebo).\n\nThe primary endpoints for Part 1 of the VacSYn trial of ACI-7104 were safety,\ntolerability and immunogenicity, all of which were met. ACI-7104 was generally\nsafe and well-tolerated and shown to be strongly immunogenic, with 100% of\npatients developing antibodies against the immunizing a-syn target antigen\nPD01 after three immunizations. Antibody reactivity against the aggregated\nspecies of a-syn was also demonstrated. Robust antibody penetration into the\ncerebrospinal fluid (CSF) was observed in all patients.\n\nPart 1 of VacSYn was not designed for biomarker or clinical outcomes\nevaluation; however, additional exploratory analyses included monitoring the\nimpact of ACI-7104 treatment on certain biomarkers (such as total a-syn and\nNeurofilament Light chain in the CSF), as well as clinical measures of disease\nactivity. A signal was observed for total a-syn in the CSF, providing\npreliminary evidence consistent with target engagement. Exploratory\ncorrelation analyses identified trends suggesting an association between\nimmunogenicity (antibody levels) and disease activity measures. While the\nsample size in Part 1 was limited, these observations provide a clear basis\nfor further investigation.\n\nThe VacSYn trial of ACI-7104 in early-stage Parkinson’s disease continues in\nPart 1 (2-year extension) and is advancing toward the initiation of Part 2\n(expansion). The final design of Part 2 is being consolidated and will be\nsubmitted to the FDA for review, with meetings expected early in 2027.\n\nMartin Zügel, Interim CEO of AC Immune SA, commented: “The results from\nthe complete data set at week-100 in Part 1 are encouraging, with all primary\nendpoints met, strong immunogenicity demonstrated, and a 100% response rate.\nThis program is one of our strongest active immunotherapies, with\nACI-7104-induced antibodies demonstrating preferential binding to aggregated\na-syn species. We will now refine our approach to the next development steps\nin the program and discuss our plans with regulators before embarking on an\nexpanded Phase 2 trial designed to provide evidence of clinical activity as\nthe basis for entry into Phase 3.”\n\nGünther Staffler, Executive Vice President, Development at AC Immune SA,\ncommented: “We are pleased to have observed strong and boostable immune\nresponses, with significant antibody penetration into the CSF and signals for\ntarget engagement. Together with the favorable safety profile through\nweek-100, and exploratory correlations between antibody titers and disease\nactivity measures, we are confident that these results provide a strong\nfoundation for the continued development of ACI-7104 into Part 2.”\n\nConference call details:\nParticipants may call the following numbers, 10 – 15 minutes before\nconference start\n\nSwitzerland / Europe:    +41 (0) 58 310 50 00\n\nUnited Kingdom:           +44 (0) 203 059 58 63\n\nUnited States:               +1 (1) 631 570 56 13\n\nHD Web Phone™:        Click Here\n\nOther international numbers available HERE\n\nWebcast link:\nhttps://event.choruscall.com/mediaframe/webcast.html?webcastid=lUHjSJWK\n\nA live and archived webcast will also be accessible in the Investors section\nof the Company's website at https://www.acimmune.com/.\n\nEnds\n\nFor further information, please contact:\n\n SVP, Investor Relations & Corporate Communications                                                \n \nGary Waanders, Ph.D., MBA AC Immune Phone: +41 21 345 91 91 Email: gary.waanders@acimmune.com    \n International Media  Optimum Strategic Communications                                             \n Nick Bastin, Joshua Evans, Aoife Minihan, Ben Cowe                                                \n Phone: +44 (0) 20 4566 8543 Email: acimmune@optimumcomms.com                                      \n                                                                                                   \n\nAbout VacSYn\n\nVacSYn (ClinicalTrials.gov: NCT06015841\n(https://www.globenewswire.com/Tracker?data=Bwj09Ke19Rq3D-XhcpmiKXHA60ExHxAVrm51uNLLzAEIZ6wlPvIfZ2PFaLUsNbZ6YdI1Py4ztOL7KowpQbmw82diEgp0wRxJ9hZn7IiCuCzjqZPXZKgYw5yTnTNdStN7JnIMaP5urLMIj3tZ957taOU3F6Y2_GLUjNH1AUazQM4=))\nis an adaptive, randomized, double-blind, placebo-controlled, and\nbiomarker-based Phase 2 study in patients with early PD, consisting of two\nparts. Part 1 includes 34 patients randomized 3:1 to receive ACI-7104 or\nplacebo, respectively. The results reported today include data from all\nparticipants 100 weeks since initiation of treatment. The study is being\nconducted in two parts with the aim for Part 1 being to show safety,\ntolerability and immunogenicity while Part 2 is designed to provide evidence\nof clinical activity and support a Phase 3 decision.\n\nAbout ACI-7104\n\nACI-7104.056 is an optimized formulation of its clinically validated\nanti-a-syn predecessor active immunotherapy that generated a target-specific\nantibody response against pathological oligomeric a-syn to inhibit spreading\nand downstream neurodegeneration in early Parkinson’s disease. The\naccumulation of alpha-synuclein protein aggregates has been shown to cause\ninflammatory stress in cells and contribute to the degeneration of neurons in\nthe brain. It has been known to play a key role in the development of\nneurodegenerative diseases such as Parkinson’s Disease.\n\nAbout AC Immune SA \n\nAC Immune (NASDAQ: ACIU) is a clinical-stage biopharmaceutical company\ndeveloping a pipeline of products, including both active immunotherapies and\nsmall molecules, targeting key misfolded proteins and pathways for the\ntreatment of multiple neurodegenerative diseases. The company has a growing\nfocus on its wholly owned proprietary clinical-stage programs, including:\nACI-7104, an active immunotherapy targeting α-synuclein (α-syn) in\nParkinson's disease; and ACI-19764, a small molecule inhibitor of the NLRP3\ninflammasome. In addition, an early-stage small molecule development program\ntargeting intracellular a-syn is advancing towards the clinic.\n\nACIU has a strong track record of securing strategic partnerships with leading\nglobal pharmaceutical companies, resulting in substantial non-dilutive funding\nand >$4.5 billion in potential milestone payments, plus royalties from sales.\nACIU’s pharma-partnered programs, all in Alzheimer’s disease, include: a\ncollaboration on ACI-24, an active immunotherapy targeting Abeta; a\ncollaboration on ACI-35 targeting phospho-Tau; and a collaboration developing\nbrain-penetrant small molecule drugs targeting intracellular pathologic Tau.\n\nAll trademarks used or mentioned in this release are protected by law. The\ninformation on our website and any other websites referenced herein is\nexpressly not incorporated by reference into, and does not constitute a part\nof, this press release.\n\nForward looking statements\n\nThis press release contains statements that constitute “forward-looking\nstatements” within the meaning of Section 27A of the Securities Act of 1933\nand Section 21E of the Securities Exchange Act of 1934. Forward-looking\nstatements are statements other than historical fact and may include\nstatements that address future operating, financial or business performance or\nAC Immune’s strategies or expectations. In some cases, you can identify\nthese statements by forward-looking words such as “may,” “might,”\n“will,” “should,” “expects,” “plans,” “anticipates,”\n“believes,” “estimates,” “predicts,” “projects,”\n“potential,” “outlook” or “continue,” and other comparable\nterminology. Forward-looking statements are based on management’s current\nexpectations and beliefs and involve significant risks and uncertainties that\ncould cause actual results, developments and business decisions to differ\nmaterially from those contemplated by these statements. These risks and\nuncertainties include those described under the captions “Item 3. Key\nInformation – Risk Factors” and “Item 5. Operating and Financial Review\nand Prospects” in AC Immune’s Annual Report on Form 20-F and other filings\nwith the Securities and Exchange Commission. Forward-looking statements speak\nonly as of the date they are made, and AC Immune does not undertake any\nobligation to update them in light of new information, future developments or\notherwise, except as may be required under applicable law. All forward-looking\nstatements are qualified in their entirety by this cautionary statement.\n\nAttachment\n*     FINAL__ACIU ACI-7104 Part 1 week 100 VacSYn Phase 2 results PR\n(https://ml-eu.globenewswire.com/Resource/Download/80ba5739-f9d7-4152-b1e0-756e1aa09395)\n(https://www.globenewswire.com/NewsRoom/AttachmentNg/0065cdfd-b9fc-4994-8aca-731c1d031b51)\n\n\n\nGlobeNewswire, Inc. 2026"},"type":"article","timestamp":"2026-09-23T11:00:02.228195869Z","server_sent_at_ms":1790161202228},"received_at":"2026-09-23T11:00:02.382Z","source_url":null},"analysis":{"id":"139454","press_release_id":"150658","analysis_json":{"industry":{"label":"Biotechnology","sector":"Health Care"},"redFlags":["Part 1 was not designed to assess clinical efficacy; exploratory biomarker signals based on small sample size (34 patients)","Phase 3 path still contingent on FDA alignment expected only in early 2027"],"eventType":"clinical_trial","narrative":"AC Immune reported positive week-100 results from Part 1 of the VacSYn Phase 2 trial of ACI-7104 in early-stage Parkinson's disease, with all primary endpoints of safety, tolerability and immunogenicity met.\n\n100% of treated patients developed antibodies against the a-syn target after three immunizations, with robust antibody penetration into the CSF and preliminary signals of target engagement.\n\nPart 2, designed to show clinical activity as the basis for a Phase 3 decision, is being finalized, with FDA meetings expected early 2027.","sentiment":"bullish","agentHooks":{"shouldPost":true,"suggestedAngle":"Lead Parkinson's vaccine candidate de-risked: 100% immunogenicity and CSF penetration clear the way for pivotal-stage Part 2 and FDA talks in early 2027."},"keyFigures":{"drugName":"ACI-7104","phaseOfTrial":"Phase 2","customDimensions":{"trial_name":"VacSYn","data_timepoint":"week-100","patients_treated":25,"placebo_patients":9,"fda_meeting_timing":"early 2027","patients_randomized":34,"immunogenicity_response_rate":"100%"}},"quotedText":"The results from the complete data set at week-100 in Part 1 are encouraging, with all primary endpoints met, strong immunogenicity demonstrated, and a 100% response rate.","namedEntities":{"people":[{"name":"Martin Zügel","role":"Interim CEO"},{"name":"Günther Staffler","role":"Executive Vice President, Development"},{"name":"Gary Waanders","role":"SVP, Investor Relations & Corporate Communications"}],"products":["ACI-7104","ACI-7104.056","VacSYn","ACI-24","ACI-35","ACI-19764"],"companies":[{"name":"AC Immune SA","ticker":"ACIU","relationship":"filer"},{"name":"FDA","relationship":"regulator"}],"dollarAmounts":[{"amount":">$4.5 billion","context":"potential milestone payments from pharma partnerships"}]},"materialImpact":{"score":4,"reasoning":"Positive Phase 2 Part 1 readout for lead Parkinson's immunotherapy ACI-7104: all primary endpoints met (safety, tolerability, immunogenicity) with 100% seroconversion and CSF antibody penetration, supporting advancement toward Part 2 and a Phase 3 path. Not a binary FDA event, but a meaningful pipeline de-risking catalyst for a clinical-stage biotech."},"tickerRelevance":{"others":[],"primary":"ACIU"},"globalImportance":38,"audienceRelevance":30,"eventTypeSecondary":[],"importanceComponents":{"tickerTier":"small-cap clinical-stage biotech","eventGravity":"positive Phase 2 interim readout, non-binary","sectorWeight":"biotech pipeline catalyst","householdBrandBoost":0,"retailFavoriteBoost":0}},"event_type":"clinical_trial","event_type_secondary":null,"sentiment":"bullish","material_impact_score":4,"narrative":"AC Immune reported positive week-100 results from Part 1 of the VacSYn Phase 2 trial of ACI-7104 in early-stage Parkinson's disease, with all primary endpoints of safety, tolerability and immunogenicity met.\n\n100% of treated patients developed antibodies against the a-syn target after three immunizations, with robust antibody penetration into the CSF and preliminary signals of target engagement.\n\nPart 2, designed to show clinical activity as the basis for a Phase 3 decision, is being finalized, with FDA meetings expected early 2027.","key_figures":{"drugName":"ACI-7104","phaseOfTrial":"Phase 2","customDimensions":{"trial_name":"VacSYn","data_timepoint":"week-100","patients_treated":25,"placebo_patients":9,"fda_meeting_timing":"early 2027","patients_randomized":34,"immunogenicity_response_rate":"100%"}},"named_entities":{"people":[{"name":"Martin Zügel","role":"Interim CEO"},{"name":"Günther Staffler","role":"Executive Vice President, Development"},{"name":"Gary Waanders","role":"SVP, Investor Relations & Corporate Communications"}],"products":["ACI-7104","ACI-7104.056","VacSYn","ACI-24","ACI-35","ACI-19764"],"companies":[{"name":"AC Immune SA","ticker":"ACIU","relationship":"filer"},{"name":"FDA","relationship":"regulator"}],"dollarAmounts":[{"amount":">$4.5 billion","context":"potential milestone payments from pharma partnerships"}]},"model_name":"glm-5.3-flashx","prompt_hash":"sha256:727b4b9429a443af","schema_hash":"sha256:05005c02d9cffac9","created_at":"2026-09-23T11:00:14.131Z","global_importance":38,"audience_relevance":30,"importance_components":{"tickerTier":"small-cap clinical-stage biotech","eventGravity":"positive Phase 2 interim readout, non-binary","sectorWeight":"biotech pipeline catalyst","householdBrandBoost":0,"retailFavoriteBoost":0}},"durationMs":6357,"modelName":"glm-5.3-flashx"}}