Japan looks set to follow EU in rejecting Alzheimer's drug Aduhelm

The Japanese regulator looks like it could follow the European Commission and reject approval of Biogen and Eisai's Alzheimer's disease therapy Aduhelm, leaving the FDA an outlier in its stance on the drug.

An advisory committee to the Ministry of Health, Labour and Welfare (MHLW) has declined to approve Aduhelm (aducanumab), saying the data from its two main clinical trials is hard to interpret, and is seeking additional data.

It also questioned that there has been a definite link shown between reduced beta amyloid in the brain and improved cognitive symptoms in Alzheimer's disease.

Biogen and Eisai have out a brave face on the outcome, saying that the First Committee on New Drugs (NDC) "has decided to continue deliberations on the application for the manufacturing and marketing approval of aducanumab."

The two companies added that they will continue to actively engage with the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan "to agree on additional data requirements," adding that they remain committed to bringing the drug to patients in Japan.

The specific nature of the new data that will be needed by the Japanese authorities isn’t yet clear, but if it involves a new trial it could delay the drug in Japan for years. Biogen is due to start a confirmatory trial of the drug next year, but it isn’t due to generate results until 2026.

If that is the case it will be a big blow to Biogen and Asia. Japan has been held up as a key market for Aduhelm, thanks to its ageing population with around 37 million people expected to be over 65 by 2030. More than 8 million people in Japan are believed to have dementia or mild cognitive impairment.

The news rounds off a torrid few days for Biogen and Eisai, coming after the EC decision to reject Aduhelm – taking issue not only with the drug's efficacy but also its safety, focusing on cases of amyloid-related imaging abnormalities (ARIAs).

Biogen has however said it will seek a re-examination of the opinion by the EMA's human medicines committee.

Shortly after the EU decision, Biogen said it was cutting the price of the drug in the US in half from $56,000 to $28,200 a year, ahead of a review by the Center for Medicare and Medicaid Services (CMS) into reimbursement which is expected to deliver a verdict in mid-January.

The timing of that move has led to speculation that the company is not expecting a positive outcome from the CMS at Aduhelm's original price point. The Institute for Clinical and Economic Review (ICER), which said in July Aduhelm's price should be slashed to $3,000 to $8,400 a year.