Biogen, Eisai face down another Aduhelm refusal—this time from Japanese regulators

Bottle and box for Aduhelm, Biogen Alzheimer's medicine
With both the EU and Japan out of reach, the focus of Aduhelm is shifting back to the U.S. (Biogen and Eisai)

Biogen and Eisai’s attempt to expand controversial Alzheimer’s disease drug Aduhelm has hit a snag in another large market.

A drug evaluation panel at Japan’s health ministry has refused to approve Aduhelm in Alzheimer’s, the two companies said Wednesday.

After a special meeting, the Japanese drug reviewers ruled that existing data didn’t support an approval and are therefore seeking additional clinical data. Biogen and Eisai are now working with the country’s Pharmaceuticals and Medical Devices Agency to settle on the specifics of additional data requirements.

Those data could take years to generate. Biogen and Eisai unveiled a plan last week to start an FDA-mandated phase 4 confirmatory study of Aduhelm in May 2022. Based on experience from past phase 3 trials, the pair expects to have data from a primary analysis in 2026.

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Eisai CEO Haruo Naito previously highlighted the large market potential for Aduhelm in Asia, including Japan and China. Without giving a number, Naito told Nikkei that he expected significant contribution from Aduhelm to Eisai’s earnings. Analysts at Jefferies had recently estimated the drug could generate $878 million in Japan in Eisai's fiscal year that ends in March 2030.

The cold shoulder from Japan came less than a week after a rejection from the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP). In refusing Aduhelm, the European agency pointed to uncertainties in the drug’s effect in Alzheimer’s clinical progression as well as concerns about a frequent and potentially life-threatening side effect known as amyloid-related imaging abnormalities.

Biogen has said it will request a reexamination of the negative opinion by the CHMP.

With both the EU and Japan out of reach for now, the focus of Aduhelm is shifting back to the U.S., where the FDA’s accelerated approval in June remains hotly debated. Next up, the U.S. Centers for Medicare & Medicaid Services is slated to reach a draft policy on Medicare coverage for Aduhelm in January.

RELATED: Biogen halves Aduhelm's price and plots cost cuts as Medicare decision on controversial Alzheimer's drug nears

Ahead of that key reimbursement decision, Biogen recently slashed Aduhelm’s price in half. Starting 2022, the annual maintenance cost of Aduhelm will be $28,200 for a patient weighting 74 kg (163 pounds). The company believes a favorable coverage decision could lead to 50,000 patient starts next year.

In a Monday note to clients, analysts at Jefferies wrote that the Medicare ruling could go a number of ways. One could feature restrictions in eligible patients or the so-called coverage with evidence development, which requires clinical study participation as a condition of coverage.

Biogen has been struggling with convincing doctors to use Aduhelm, as reflected in the drug’s $300,000 sales in the third quarter. Under pressure from Aduhelm’s miserable launch, the company is embarking on a cost cutting program that aims to save $500 million in annual costs.