AC Immune Reports Positive Results for ACI-7104.056 Clinical Trial
AC Immune announced positive interim safety and efficacy results from the Phase 2 VacSYn trial of its wholly-owned anti-alpha-synuclein active immunotherapy ACI-7104.056 in early Parkinson's disease, or PD. Results show, for the first time, that targeting a-syn pathology with an active immunotherapy could potentially slow the rate of progression of PD. Disease-related biomarker results suggest stabilization of PD pathology. In addition, total scores are suggestive of a trend for stabilization. Interim results showed all target criteria for immunogenicity were met, including: ACI-7104.056 induced a robust antibody response against the immunizing a-syn target antigen with a 100% responder rate; titers against the immunizing a-syn target antigen increased with successive immunizations, showing ACI-7104.056 generates antibodies that cross the blood-brain barrier. The stabilization of disease-relevant biomarkers in the central nervous system, suggests slowing of Parkinson's disease pathology, with potential disease modification. Levels of Neurofilament Light chain in the CSF remained stable in the ACI-7104.056 group and increased in the placebo group. Stabilization suggests a potential slowing of neuronal damage. Interim results from weeks 50 and 76 continue to demonstrate that ACI-7105.056 is generally safe and well-tolerated enabling a positive benefit/risk ratio. AC Immune aims to seek regulatory feedback on an ACI-7104.056 clinical development plan to potentially accelerate towards registration. Final data from Part 1 of the VacSYn trial are expected in mid-2026.
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- Financial Performance Decline: AC Immune reported a FY 2023 GAAP EPS of -CHF0.70 and revenue of CHF3.57 million, reflecting an 86.9% year-over-year decline, indicating significant pressure on the company's market position and profitability.
- R&D Progress Stalled: While maintaining a 'Buy' rating on the development of ACI-7104.056 for PDAC, AC Immune's partner Johnson & Johnson has paused enrollment in the mid-stage trial for its Alzheimer's drug, which could impact future R&D timelines and market outlook.
- Negative Market Reaction: The substantial deterioration in financial data and uncertainty surrounding R&D progress have shaken market confidence in AC Immune, potentially leading to short-term stock price pressure and affecting investor sentiment.
- Historical Performance Review: Historical earnings data for AC Immune shows that despite current challenges, the company has had notable successes in the past, suggesting that strategic adjustments and innovation will be crucial for restoring growth moving forward.

- Funding Overview: Cash resources of CHF 91.4 million are available as of December 31, 2025.
- Funding Timeline: These resources are intended to provide funding until the end of Q3 2027.
- Trial Suspension: AC Immune's mid-stage trial ReTain for the Alzheimer's candidate ACI-35.030/JNJ-2056 has temporarily paused enrollment as partner Johnson & Johnson evaluates various aspects of the trial, including recruitment, which may impact the drug's market entry timeline.
- Financial Stability: Despite the trial's pause, AC Immune has stated that J&J's decision will not affect its liquidity position, as existing capital resources are sufficient to fund operational needs into Q3 2027, ensuring stability in its R&D efforts.
- Collaboration Background: The drug's development stems from a licensing and commercialization agreement signed in 2015, allowing AC Immune to initially receive up to $509 million from J&J, highlighting the long-term collaborative potential in Alzheimer's treatment.
- Market Reaction: AC Immune's stock price may be affected by the trial suspension news; although the company has confirmed liquidity is secure, investor concerns regarding the drug's development progress could lead to short-term market volatility.

Interim Results from VacSYn Trial: AC Immune SA reported promising interim safety and efficacy results from its Phase 2 VacSYn trial for the anti-alpha-synuclein immunotherapy ACI-7104.056, indicating potential slowing of Parkinson's disease progression through stabilization of disease-related biomarkers.
Robust Antibody Response: The treatment induced a strong antibody response against the target antigen, with a 100% responder rate and significantly higher antibody levels in both serum and cerebrospinal fluid compared to the placebo group.
Clinical Measures of Stabilization: Clinical assessments showed that the ACI-7104.056 group did not experience meaningful progression in motor symptoms, contrasting with the expected increase in the placebo group, suggesting a trend toward disease stabilization.
Future Expectations: The trial results are generally safe and well-tolerated, with final data from Part 1 of the VacSYn trial anticipated in mid-2026, while AC Immune's stock saw a notable increase following the announcement.

- Clinical Trial Success: AC Immune's Phase 2 VacSYn trial of ACI-7104.056 demonstrates, for the first time, that targeting alpha-synuclein pathology with active immunotherapy may slow the progression of Parkinson's disease, marking a significant breakthrough in treatment.
- Strong Safety Profile: The therapy was administered to 34 patients, all treated for at least 12 months, with no clinically relevant adverse events reported, indicating a favorable safety and tolerability profile.
- Robust Immune Response: By week 76, the ACI-7104.056 group exhibited antibody titers over 500 times higher than the placebo group, achieving a 100% responder rate, showcasing the therapy's potential to induce a strong immune response and laying the groundwork for future treatments.
- Stabilization of Biomarkers: The treatment group showed stable levels of neurofilament light chain (NfL), a marker of neuronal damage, while levels increased in the placebo group, suggesting that the therapy may effectively slow neuronal damage, which has significant clinical implications.

- Clinical Trial Results: AC Immune's Phase 2 VacSYn trial demonstrates for the first time that the active immunotherapy ACI-7104.056 may slow the progression of Parkinson's disease by targeting alpha-synuclein pathology, marking a significant breakthrough in treatment options.
- Safety and Immunogenicity: The therapy achieved a 100% responder rate in a cohort of 34 patients with no clinically relevant safety issues reported, indicating a strong safety profile and tolerability that supports further development.
- Biomarker Stability: In the treatment group, levels of alpha-synuclein in cerebrospinal fluid remained stable, contrasting with a decline in the placebo group, suggesting that ACI-7104.056 may stabilize pathology through antibody binding, indicating potential disease-modifying effects.
- Future Development Plans: Following these promising interim results, AC Immune aims to engage with regulators to discuss a clinical development plan for ACI-7104.056, with the goal of accelerating the registration process, and final data from the trial are expected in mid-2026.






