AC Immune reports positive early Phase 1 data for NLRP3 inhibitor ACI-19764

AC Immune SA announced on August 20, 2026 that a Phase 1 first-in-human study of ACI-19764, its wholly owned oral inhibitor of the NLRP3 inflammasome, produced positive preliminary results in healthy volunteers in Europe. The study is investigating the safety, tolerability, pharmacokinetics, and pharmacodynamics of ACI-19764 in healthy volunteers in Europe.¹ Preliminary results show the drug was safe and well tolerated to date across both single ascending dose and multiple ascending dose cohorts, including doses up to 20mg per day, with a serum half-life greater than 30 hours.¹ There have been no serious adverse events to date and no treatment withdrawals.¹

Clear evidence of brain penetration was observed based on cerebrospinal fluid exposure.¹ Daily doses of 10mg or less achieved pharmacokinetic concentrations above the IC90, and a blinded review of whole blood assay data showed dose dependent inhibition of IL-1beta release.¹ Based on PK data the therapeutic dose is expected to be 10mg or less once daily.¹

The trial has now commenced dosing of first patients with cardiovascular disease risk, as determined by elevated serum levels of high-sensitivity C-reactive protein and the presence of either type 2 diabetes and/or obesity.¹ Recruitment of this Phase 1b cohort is ongoing and initial results are expected before year end.¹

Supported by a preclinical data package including 3-month toxicology data, ACI-19764 continues to advance through its Phase 1/1b clinical study, with additional data expected in H1 2027.¹ In prior in vitro testing, ACI-19764 showed high potency as demonstrated by the downstream inhibition of IL-1β production by human macrophages and human whole blood with an IC50 in the range of 2-20.5nM.¹