Alzheimer’s and Down Syndrome Vaccine Candidate Advances

ACI-24 is an anti-Abeta vaccine against Alzheimer's disease and Abeta-related cognitive decline in Down Syndrome
older man reading  a book in a garden
(Precision Vaccinations News)

A clinical-stage biopharmaceutical company announced 2 clinical milestones related to ACI-24, an anti-Abeta vaccine candidate against Alzheimer's disease and the Abeta-related cognitive decline in Down Syndrome.

ACI-24 is a liposomal therapeutic anti-Abeta vaccine candidate, which generates antibodies specific to disease-causing conformations. 

The vaccine is designed by AC Immune to stimulate a patient's immune system to produce antibodies that specifically target the oligomeric and fibrillary Abeta proteins, to prevent plaque accumulation and to enhance plaque clearance.

Andrea Pfeifer, the CEO of AC Immune, said in a press release, "We are delighted with the progress of ACI-24, which is currently the only clinical-stage vaccine targeting the associated Abeta-induced cognitive decline in people with Down Syndrome.”

“Vaccines are potentially an important option for the treatment and prevention of neurodegenerative diseases."

This announcement highlighted two aspects of ACI-24:

ACI-24 Vaccine for Alzheimer's Disease (AD):

  • AC Immune has started the Phase 2 study with ACI-24 in patients with mild Alzheimer's disease (AD). The aim of this double-blind, randomized, placebo-controlled study is to confirm the positive trends of Abeta PET* imaging and clinical measurement (CDR-SB°) of the previous Phase 1 safety study. The Phase 2 trial will be conducted in several European countries and the first patients have been screened.
  • Alzheimer's disease is one of the biggest burdens of society with 50 million people worldwide living with dementia, says the WHO. Since the incidence and prevalence of AD increases with age, the number of patients will grow significantly as society ages.

ACI-24 in Down Syndrome:

  • AC Immune has completed recruitment for the high-dose cohort of the ACI-24 Phase°1b study for the treatment of Alzheimer's disease-like characteristics in adults with Down Syndrome (DS), a condition affecting approximately one in 700 newborns. In addition to cognitive dysfunction beginning in childhood, individuals with DS are genetically-predisposed to develop Abeta-related cognitive decline at a much younger age and with much greater probability than the general population.
  • Individuals with Down Syndrome have an extra copy of chromosome 21 which carries the gene for the Amyloid Beta Precursor Protein (APP) encoding the precursor protein of Abeta, one of the hallmarks of AD. An important consequence is that almost all subjects with Down Syndrome older than 40 years exhibit neuropathological changes similar to AD, says the NIH. 

This is a prospective multi-center, placebo controlled, double-blind and randomized dose escalation study of 2 doses of ACI-24 versus Placebo over 24 months with a total of 21 visits.

All subjects will receive the study medication (ACI-24 or Placebo) 7 times via subcutaneous injection (12 months) and will be followed up for 12 months after the last dose with a final safety and efficacy assessment.

To learn more about the Phase 1b clinical trial (3 Star Study), please visit NCT02738450.

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