AXON’s Tau Vaccine Shows Promise for Alzheimer’s and Dementia Patients

AXON Neuroscience announced that AADvac1, a vaccine against tau (a protein that accumulates and forms tangles inside neurons in diverse neurodegenerative diseases) showed therapeutic potential in Alzheimer’s disease (AD) and frontotemporal dementia (FTD) in a Phase 1 study.

The announcement was made by Matej Ondrus, MD, the company’s medical director, at Axon’s symposium, “Frontiers in diagnostics and therapy of human tauopathies,” held at the 13th International Conference on Alzheimer’s & Parkinson’s Diseases (AD/PD 2017) in Vienna, Austria.

Intracellular tangles of tau are associated with neuronal loss and with severity of dementia. Immunotherapy using the AADvac1 vaccine aims to induce the patient’s immune system to produce specific antibodies against abnormal forms of tau, with the ultimate goal of protecting neurons from degeneration.

The Phase 1 study (NCT01850238) revealed that the antibodies elicited by vaccination with AADvac1 could recognize pathological tau in brains from Alzheimer’s patients. This response could prevent, at least partially, the progression of the disease.

Furthermore, results from an 18-month follow-up study showed that similar responses were obtained in corticobasal degeneration and progressive supranuclear palsy, two other neurodegenerative diseases. These data strongly suggest that the antibodies produced by the AADvac1 vaccine target a common denominator in diverse diseases.

“In this 96-week study, we demonstrated that the vaccine is safe and we can detect first signals in the therapeutic efficacy,” Norbert Zilka, PhD, AXON’s chief science officer, said in a press release. “We have observed a significant correlation between the amount of specific antibodies in the blood of treated patients and cognitive status. This finding nicely reflects our preclinical data.”

AXON is currently proceeding with the 24-month Phase 2 ADAMANT study (NCT02579252) to evaluate safety and tolerability, as well as effectiveness and potential biomarkers of ADDvac1 treatment in patients with mild Alzheimer’s. The trial is recruiting patients.

And, in cooperation with the German FTLD (Frontotemporal Lobar Degeneration) Consortium, AXON is starting a pilot Phase 1 study testing AADvac1 in patients with the non-fluent variant of primary progressive aphasia (nfvPPA) – a subgroup of FTD.

As in Alzheimer’s, tau pathology is one of the key drivers of nfvPPA. During the initial phase of the disease, nfvPPA is characterized by a prominent  language deficit, which affects conversation and speech slowly and progressively. Other cognitive and motor functions may also be impaired during the course of the disease.

“We are studying FTD patients at the FTLD Consortium for a long time and this is the first time to offer a perspective treatment to them,” said Markus Otto, MD, from the Department of Neurology at Ulm University Hospital in Germany and leader of the FTLD Consortium. “Finally, we are to accomplish with AXON the big milestone in these indications, where the unmet medical need is exceptionally high.”

The company said this will be the first time that nfvPPA patients will participate in a clinical study with disease-modifying potential.