Biogen's Alzheimer's drug Aduhelm is rejected by EU advisors

The EMA's human medicines committee has said it cannot approve Biogen and Eisai's Alzheimer's disease therapy Aduhelm, saying it was unconvinced by the data submitted for the drug.

The companies had already indicated that the CHMP looked likely to turn down their marketing application for Aduhelm (aducanumab), but the decision nevertheless is a heavy blow, coming as take-up of the drug has pretty much stalled in the US.

In a statement, the EMA said that while Aduhelm clearly reduces levels of amyloid beta in the brain, "the link between his effect and clinical improvement had not been established."

It also said that the results of the two studies submitted by Biogen in support of the application "were conflicting and did not show overall that Aduhelm was effective at treating adults with early stage Alzheimer's disease."

Finally  – in another hammer blow – the EMA also questioned the safety of Aduhelm, concluding that the studies "did not show that the medicine was sufficiently safe."

There have been concerns about cases of amyloid-related imaging abnormalities (ARIAs) - brain swelling or bleeds seen with Aduhelm treatment – that can resolve over time but in some cases can be serious.

"It is not clear that the abnormalities can be properly monitored and managed in clinical practice," said the EMA in a question and answer document published alongside the CHMP decision.

Biogen can seek a re-examination of the opinion by the CHMP within the next 15 days, and has already said it will do so.

"For Europeans impacted by Alzheimer's disease, the lack of options to treat its early stages is felt every day," asserted Priya Singhal, Biogen's interim head of R&D following the shock departure of Al Sandrock a few weeks ago.

"The longer we wait, the more people will progress toward more advanced dementia and we may miss the opportunity to potentially treat them," she added.

Biogen said it would seek clarification of the CHMP's grounds for refusing the marketing application.

The decision was welcomed by some clinicians, including Robert Howard, professor of Old Age Psychiatry at UCL in London, who said Aduhelm is "a treatment without convincing efficacy, with serious associated adverse effects and a high financial cost."

He went on to say that "on the basis of the available evidence and in the best interests of people with Alzheimer's disease, their families and those who care for them, EMA and [UK drugs regulator] MHRA should not approve a license for aducanumab."

Patient organisation the Alzheimer's Society and Alzheimer's Research UK in the UK stopped short of calling for a different outcome from the EMA review, and merely expressed disappointment that there were still no therapies that can slow down cognitive decline in people with dementia.

"The EMA is now undertaking its own review of the data and it's important that we wait for the committee's official recommendation, which is expected next month," said David Thomas, head of policy at Alzheimer's Research UK.

"In the meantime, we must continue to work at pace to ensure researchers are developing a broad pipeline of potential new treatments for diseases like Alzheimer's, and that health systems like the NHS will be ready to deliver them in the years ahead," he added.