AC Immune SA announced positive interim results from its ongoing Phase 1b/2a clinical trial evaluating its first-in-class anti-phospho-Tau (pTau) vaccine candidate ACI-35.030 for the treatment of Alzheimer’s disease (AD). ACI-35.030 vaccination generated a potent antigen-specific antibody response against pTau in 100% of older patients with early AD, achieving antibody levels several orders of magnitude higher than pre-vaccination levels. No clinically relevant adverse events were observed.
The pTau AD vaccine trial is a randomized, multicenter, double-blind, placebo-controlled clinical study with a primary objective to assess the safety, tolerability and immunogenicity of different doses of ACI-35.030 over a 48-week treatment phase in 32 patients with early AD. Additional endpoints include clinical and cognitive parameters as well as additional immunogenicity and safety parameters.
The data demonstrated anti-tau IgG response preferentially targeted pTau in all patients, with 100% response after the first injection at both the lowest and second highest dosages. Very high anti-pTau IgG levels were observed after injection and the IgM response was also observed in all patients for both doses. The drug was safe and well tolerated with no clinically relevant safety issues.
The trial will now advance to the third and highest dosing group, per the study protocol.
AC Immune is developing the ACI-35.030 vaccine in collaboration with Janssen Pharmaceuticals, under a 2015 licensing agreement to develop and commercialize therapeutic anti-Tau vaccines for the treatment of AD and potentially other Tauopathies.
ACI-35.030 is a potent liposomal anti-pTau active vaccine designed to elicit antibodies against phosphorylated pathological Tau protein. It is designed to reduce and facilitate the clearance of related Tau aggregates, slowing the progression of Tau-pathology and/or treating the underlying Tauopathy. ACI-35.030 is derived from AC Immune’s proprietary SupraAntigenTM platform.
It builds on the success of AC Immune’s ACI-35 vaccine, which demonstrated an early target-specific antibody response against pTau after the first injection in the majority of patients in a Phase 1b study in mild-to-moderate AD. In preclinical studies, ACI-35.030 retained the excellent non-clinical safety profile and the highly specific antibody response against phosphorylated pathological Tau produced by ACI-35, while demonstrating an enhanced and more homogeneous antibody response.