AC Immune SA has announced peer-reviewed results from its phase 1b/2a trial of two Tau-targeting active immunotherapies for early Alzheimer’s disease.
The study compared ACI-35.030, developed with AC Immune’s SupraAntigen technology, and JACI-35.054, both targeting the same pTau peptide sequence.
ACI-35.030 demonstrated a rapid, potent and sustained polyclonal antibody response against pathological forms of Tau, including phosphorylated Tau (pTau) and brain-derived Tau (ePHF), after a single dose.
All participants were classified as anti-pTau IgG responders within two weeks, with response rates between 94% and 100% maintained through week 74 in high-dose cohorts. The therapy also showed specificity, as antibody levels against normal Tau declined with subsequent doses.
In contrast, JACI-35.054 produced a more variable response and required multiple administrations to reach consistent antibody levels. It also induced antibodies against normal Tau after the second dose, which increased with further treatment.
No clinically relevant safety or tolerability issues were reported for either therapy. Based on its performance, ACI-35.030 (also known as JNJ-2056) was selected to advance into the ongoing Phase 2b ReTain trial, which is investigating the therapy in approximately 500 participants with preclinical Alzheimer’s disease.
Dr Andrea Pfeifer, CEO of AC Immune SA, stated: “These data show that ACI-35.030 (JNJ-2056) was well tolerated at all tested doses and induced a rapid and sustained response against pathological Tau, while requiring less frequent dosing to maintain titers as compared to monoclonal antibodies.”
She added: “This study also demonstrated the ability of AC Immune’s SupraAntigen platform to generate active immunotherapies that are highly differentiated from other approaches even when the immunogen is identical.”
