Alzheimer Disease Vaccine: Less Talk, More Numbers

Leah Kuntz

A study on a new Alzheimer disease vaccine lacks concrete numbers.

The prognosis for an Alzheimer disease (AD) vaccine remains uncertain, but there is potential for this new treatment. Biopharmaceutical company AC Immune announced positive interim results from its phase 1b/2a clinical trial studying its Alzheimer disease vaccine, ACI-35.030.

“These remarkable data show that ACI-35.030 is capable of generating unprecedented antibody responses against pTau in an elderly population, with very high antigen-specific titers. Importantly, it generated a much stronger antibody response compared to direct injection of exogenous antibodies,” CEO of AC Immune Andrea Pfeifer, PhD, said. “As pathological pTau is present as a precursor many years before Tau accumulation in the brain is detectable via brain imaging, such results highlight the significant promise of ACI-35.030 as an early intervention for AD, especially when combined with cutting-edge pTau diagnostics that would enable identification of people at risk of developing Tau-driven disease.”1

ACI-35.030 is a potent liposomal anti-pTau active investigational vaccine designed to elicit antibodies against phosphorylated pathological Tau protein.

The study, while relatively small with only 32 participants and 2 dose cohorts,2 discovered a potent antigen-specific antibody response against pTau in older patients with early AD. The vaccine achieved antibody levels several degrees of magnitude higher than prevaccination levels, and no clinically relevant adverse events were observed.

The interim data showed that anti-Tau IgG response preferentially targets phosphorylated Tau in all participants, very high anti-pTau IgG titers were observed following injection, and a demonstrated anti-pTau IgG response in all participants after the 1st injection.

But despite these encouraging signs, the data release had little in terms of concrete data, with no number attached to the supposed increased antibody levels or any median increase across the study. While this has left some investors skeptical,2 AC Immune and their strategic partner Janssen Pharmaceuticals plan to advance the development of ACI-35.030 for the treatment of AD.

“We look forward to continuing to advance ACI-35.030 in our collaboration with Janssen Pharmaceuticals, Inc, as we aim to bring this potentially breakthrough vaccine to patients,” Pfeifer said further.1

References

1. AC Immune. AC Immune’s Alzheimer’s vaccine generates potent anti-pTau antibody response in a phase 1b/2a study. News release. February 11, 2021. https://ir.acimmune.com/news-releases/news-release-details/ac-immunes-alzheimers-vaccine-generates-potent-anti-ptau

2. Mast J. AC Immune has ‘remarkable’ Alzheimer’s vaccine data. Just don’t ask to see them. Endpoint News. February 11, 2021. https://endpts.com/ac-immune-has-remarkable-alzheimers-vaccine-data-just-dont-ask-to-see-them/