Axon’s Alzheimer’s vaccine hits Phase II as it seeks to prove efficacy

Brain imaging

Slovakian biotech Axon Neuroscience has treated the first patient with its closely watched Alzheimer’s vax AADvac1--which is aiming to be the first disease-modifying tau vaccine for the memory-stealing disease.

There are two camps in Alzheimer’s research as to what causes the disease. The first, known as the amyloid cascade theory, sees the onset of Alzheimer’s disease (AD) as being connected to the buildup of an abnormal protein called amyloid-beta (Aβ), and stands as the most studied explanation of AD.

Those who support this viewpoint have been known as “baptists,” and this area has been the focus of Big Pharmas Pfizer ($PFE) and Eli Lilly ($LLY) among others--although a number of recent late-stage results have been disappointing to say the least--with the entire pipeline for drugs against the disease full of flops and failures across the industry. (Overall clinical trial failure rates in Alzheimer's have been estimated as high as 99% in the past decade.)

And then there’s the second hypothesis--which is gaining more research time--that associates the onset of the disease instead to fibrillary tangles called tau protein. Neurofibrillary tangles group in an insoluble form in neurons, affecting normal neuronal functions.

Scientists in support of this theory, the “tauists,” are attempting to target and block tau hyperphosphorylation in Alzheimer’s patients in hopes of relieving the negative consequences of the disease.

Axon is working the latter tau theory and began human testing back in 2013. AADvac1 targets the anti-tau phosphorylation and consists of synthetic polypeptides, which are meant to elicit an immune response against pathogenic tau proteins.

Phase I results, posted last year at the Alzheimer’s Association International Conference, showed it was safe and well tolerated. Now the real work begins, as it starts its larger Phase II safety and efficacy trial where the primary goal is to confirm its earlier results by assessing safety and immunogenicity on a larger sample of patients with mild Alzheimer’s disease.

As a second and more important objective for its future, the study will also evaluate the effect of the AADvac1 vaccine in slowing down or halting the cognitive decline in patients over the period of around 2 years.

The Adamant study will also explore and show the disease-modifying effect on the Clinical Dementia Rating (CDR) Sum of Boxes, supported by a custom cognitive battery (composite standard score) and activities of daily living scale. If it can tick all these boxes, Axon could have a major blockbuster on its hands.

Adamant will be conducted in several countries in Europe, where 185 patients are planned to be enrolled in the study.

“We are grateful for all the efforts of the entire team, investigators, and partners, who helped us to move AADvac1 into the Phase II study, which is a historical milestone for Alzheimer’s research and clinical development,” said Roman Sivak, CEO of Axon Neuroscience, in a release. “This is an exciting era as we believe that the positive results from the phase I study could soon be confirmed by this Phase II study.”

Axon is not the only company gunning for a tau vaccine, however, with AC Immune/Janssen’s ($JNJ) ACI-35, also an anti-tau vaccine, currently in Phase Ib.  

Researchers hope the vaccine will help stimulate the patients’ immune systems against misfolded and phosphorylated tau proteins involved in the onset of Alzheimer’s.

- check out the release

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