AC Immune Advances ACI-24 Alzheimer's Trial to Final Cohort, Initiates ACI-19764 Phase 1 Study

Key Takeaways

• AC Immune initiated the final AD4 cohort in its ABATE Phase 1b/2 trial of ACI-24 for Alzheimer’s disease treatment
• First patients dosed in Phase 1 trial of brain-penetrant NLRP3 inhibitor ACI-19764, with results expected in second half 2026
• Amended Morphomer Tau collaboration with Eli Lilly reflects increased focus on intracellular tau targeting strategies

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AC Immune Reaches Critical Alzheimer’s Trial Milestone

AC Immune SA announced significant progress in its Alzheimer’s disease pipeline during its first quarter 2026 financial update, highlighted by the initiation of the final patient cohort in its ACI-24 clinical trial and the launch of a new Phase 1 study for ACI-19764.

The Swiss biopharmaceutical company has begun dosing the AD4 cohort, representing the final group in its ABATE Phase 1b/2 trial evaluating ACI-24 as an Alzheimer’s disease treatment. This milestone triggers a payment under the company’s partnership agreements and moves ACI-24 closer to potential Phase 3 development.

New NLRP3 Inhibitor Enters Clinical Testing

Simultaneously, AC Immune dosed its first subjects in a Phase 1 trial of ACI-19764, a brain-penetrant small molecule NLRP3 inhibitor. The study will evaluate single ascending doses (SAD) and multiple ascending doses (MAD) in healthy volunteers, with results anticipated in the second half of 2026.

NLRP3 inhibitors represent a novel approach to neuroinflammation, targeting the NLRP3 inflammasome pathway implicated in Alzheimer’s disease progression. The brain-penetrant properties of ACI-19764 could offer advantages over systemic treatments by directly addressing neuroinflammation at its source.

Expanded Tau Collaboration Signals Market Confidence

The company also amended its Morphomer Tau collaboration with Eli Lilly, reflecting growing pharmaceutical industry interest in targeting intracellular tau proteins. This partnership expansion suggests increasing confidence in AC Immune’s tau-targeting platform and validates the therapeutic potential of addressing tau pathology in neurodegenerative diseases.

The developments position AC Immune with multiple shots at addressing Alzheimer’s disease through different mechanisms, potentially reducing development risk while maximizing therapeutic opportunities in the estimated $8.5 billion Alzheimer’s treatment market.

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Frequently Asked Questions

What does this mean for Alzheimer’s patients?

These trials represent potential new treatment options targeting different aspects of Alzheimer’s disease, including tau proteins and neuroinflammation, though treatments remain years away from market availability.

When will ACI-24 and ACI-19764 be available to patients?

ACI-24 is in Phase 1b/2 trials and ACI-19764 just entered Phase 1, meaning both drugs require several more years of clinical testing before potential FDA approval and market availability.

How do these treatments differ from existing Alzheimer’s drugs?

Unlike current FDA-approved treatments that target amyloid plaques, AC Immune’s pipeline addresses tau proteins and neuroinflammation, potentially offering complementary or superior therapeutic approaches.