資料來源：https://www.reuters.com/article/us-accera-study-idUSKBN1671LG

Nestle SA-backed Accera Inc said on Tuesday its experimental Alzheimer's drug failed a late-stage study, adding to the laundry list of disappointments in the pursuit of an effective treatment for the rampant mind-wasting disease.

Accera's AC-1204 failed to induce a statistically significant improvement in symptoms versus a placebo in patients with a mild-to-moderate form of the disease, the company said.

The announcement comes weeks after Merck & Co Inc said it would halt a late-stage trial of its Alzheimer's drug, verubecestat, after determining that it had no chance of working.

Verubecestat belongs to a class of experimental drugs called BACE1 inhibitors which target an enzyme involved in the formation of the toxic amyloid protein that turns into plaques in the brains of Alzheimer's patients.

Several companies are pinning hopes on this mechanism, including Eli Lilly and Co, Biogen as well as Novartis in collaboration with Amgen Inc.

But Accera's drug targets what the company believes is the cause of the build up of amyloid.

Decades before diagnosis, the brain exhibits a decreasing ability to metabolize glucose - the main food of the brain. It is this metabolic deficit that then gives rise to the deposition of amyloid, Accera Chief executive Charles Stacey told Reuters.

Researchers are increasingly focusing on attacking the disease earlier as it appears likely that once symptoms have taken hold current approaches fail to work.

Industry analysts say any treatment that successfully interferes with the cause of the disease would be virtually guaranteed multi-billion dollars in sales.

After a successful mid-stage trial, Accera decided to tweak AC-1204's formulation. But that change led to lower levels of bioavailability – or the degree by which the drug's active ingredients are absorbed by the blood – Stacey said.

"We were essentially under-dosing our patients and that's why the primary endpoint was not met."

Accera has now fixed the formulation and is readying itself for another late-stage study, pending discussions with the U.S. Food and Drug Administration, the CEO said.

The company already sells a product called Axona, launched in 2010, as a medical food labeled for the dietary management for Alzheimer's patients.

Both Axona and AC-1204 work on the same principle, but differ in terms of bioavailability, taste, format etc, Stacey said.

In 2013, the FDA censured Accera, saying Axona had been "misbranded" and did not satisfy the definition of medical food. But the issue has since been resolved and Axona remains on the U.S. market.

(Reporting by Natalie Grover in Bengaluru; Editing by Savio D'Souza)