Early data from AC Immune Alzheimer's vaccine suggest a response, setting up next phase of study

It’s early days for AC Immune’s Alzheimer’s disease vaccine, but a sneak peek at phase 1b/2 data showed the anti-amyloid beta vaccine elicited a response, allowing it to move up to a higher dose in the trial.

The Swiss company reported Thursday that ACI-24.060 elicited an anti-Abeta antibody response as early as week 6, meaning the therapy may help prevent or clear plaques in the brain thought to cause the cognitive decline in Alzheimer’s.

The interim results from the ABATE trial were focused on safety and immunogenicity from the low-dose cohort. AC Immune said the vaccine was generally well tolerated with no safety concerns flagged. The release was thin on details, beyond the headline that the shot elicited a response.

AC Immune will now up the dose and is also adding in patients with Down syndrome. The buildup of beta-amyloid plaques in the brain is a hallmark of Alzheimer’s. By age 40, most patients with Down syndrome are exhibiting these plaques and the buildup of tau tangles, which is another red flag for Alzheimer’s. Screening for those patients has now begun, according to AC Immune.

The company expects to release further immunogenicity data from the study’s cohorts in the second half of 2023. But investors will have to wait until 2024 to find out if ACI-24.060 actually reduces amyloid plaques, which AC Immune intends to measure by PET imaging.

Those will be crucial data, as Eisai and Biogen’s Alzheimer’s med Leqembi was granted an accelerated approval based on its ability to clear amyloid plaques. The partners are conducting a confirmatory study to show whether the therapy leads to improvement in cognitive function, which will be used to secure a full approval and lift restrictions on who can receive the drug. The FDA has signaled with the January accelerated approval a continued openness to using the amyloid biomarker to underpin a request for swift market access.

AC Immune is working on ACI-24.060 alone, but also has partnerships with Big Pharmas on several other assets. Most notably, the company is working with Roche’s Genentech unit on crenezumab, which failed in a phase 2 trial last year.

Another vaccine called ACI-35.030 being developed with Johnson & Johnson pharmaceutical unit Janssen just advanced into further development after the healthcare giant got a glimpse at interim phase 1b/2a data.

AC Immune’s shares climbed more than 7% to $2.51 as the markets opened Thursday, compared to a prior close of $2.34, before dropping back down to $2.35 by 10:20 a.m. ET.