It's Finally Over for Aduhelm, the Sketchy Alzheimer's Drug Everyone Hated

Biogen is abandoning its lackluster Alzheimer’s disease drug, Aduhelm. The Massachusetts-based company announced Wednesday that it is pulling the medication from the market following poor sales and controversy over its approval by the Food and Drug Administration in 2021. The company says it is only doing so to “reprioritize” its resources toward its other, less contentious Alzheimer’s treatments, such as Leqembi.

Adulhelm was developed by Biogen in conjunction with the Japanese pharmaceutical company Eisai, after being licensed from the company Neurimmune. It’s made with the active ingredient aducanumab, a lab-made antibody designed to target the misfolded version of the protein amyloid beta. In people with Alzheimer’s, this rogue amyloid beta builds up in the brain, eventually turning into damaging clumps called plaques. Because aducanumab can break down plaque in the lab, scientists hoped that it could slow or even reverse the worsening of Alzheimer’s symptoms.

The trouble is that Aduhelm never really seemed to work as intended. In 2019, Biogen ended its Phase III research early after an independent panel of experts monitoring the data determined that it likely wouldn’t meet the pre-established goals of the trials, which were to noticeably slow down patients’ loss of cognitive function. About six months later, however, the company suddenly changed course, announcing that its updated reanalysis actually did find enough evidence of the drug’s efficacy and that it would submit the drug for formal FDA approval.

But other experts didn’t buy what Biogen was selling. In November 2020, an outside advisory committee assembled by the FDA largely recommended that the FDA not approve the drug. The FDA rarely disagrees with these recommendations, but it did just that in June 2021, when it granted Aduhelm accelerated approval, a special category that requires less rigorous evidence of a drug’s effectiveness (in exchange, companies are required to run more clinical trials and eventually present solid proof of the drug’s value). The company raised further eyebrows when it announced that the drug’s list price would be $56,000 a year.

While some patient advocates did laud the drug’s approval, the reaction from the scientific community was largely negative, and swiftly so. Several experts on the FDA’s advisory committee resigned in protest, while many doctors vowed that they would not prescribe the drug to their patients. By the end of the month, the media outlet STAT News uncovered evidence of an unusually friendly relationship between top Biogen employees and FDA officials, which prompted a Congressional investigation into the matter. This investigation eventually found that the FDA’s approval process of Aduhelm was “rife with irregularities.”

But perhaps the final nail in the coffin came in April 2022, when Medicare formally enacted a policy that would severely limit its coverage of the drug and other Alzheimer’s drugs with accelerated approval until such treatments showed clear evidence of working. Around the same time, Eisai washed its hands of the whole thing and ceded complete control of the drug to Biogen.

In the wake of all this, Aduhelm has failed to generate any major sales, even after the company lowered the list price by half. According to Biogen, there are only about 2,500 people taking the drug currently, scattered across the company’s clinical, commercial, and global access programs.

Biogen will not only pull Aduhelm from the market but also terminate its remaining clinical clinical trials of it. In its announcement of the decision to fully can Aduhelm, the company denied that the move was related to “any safety or efficacy concerns.” And it claims that most of the resources dedicated to supporting the drug will simply be relocated to other parts of its Alzheimer’s development program.

“We have gained significant insight from the development of ADUHELM and will carry this forward as we continue our pioneering work in Alzheimer’s disease,” said Priya Singhal, head of development at Biogen, in the company’s announcement.

Biogen has seen more success with its second-generation anti-amyloid drug Leqembi. Unlike Aduhelm, this drug was found to clearly meet the goals of its Phase III trials in slowing people’s rate of cognitive decline. Scientists are still arguing over whether this modest reduction is really noticeable in patients’ everyday life, but Leqembi’s full FDA approval last year was generally seen in a much more positive light. And it’s possible that future similar treatments or other interventions really will lead to substantial improvements in Alzheimer’s care someday soon.

If so, then Aduhelm might just end up becoming a messy footnote in an otherwise hopeful story.