Not only is aducanumab the first Alzheimer’s drug to be approved since 2003, it’s the first therapy ever to actually target the underlying causes of the disease rather than just treat its symptoms. That means actually slowing the rate of cognitive decline in Alzheimer’s patients.

“Aduhelm is the first treatment directed at the underlying pathophysiology of Alzheimer’s disease, the presence of amyloid beta plaques in the brain,” wrote the FDA in a statement. “The clinical trials for Aduhelm were the first to show that a reduction in these plaques—a hallmark finding in the brain of patients with Alzheimer’s—is expected to lead to a reduction in the clinical decline of this devastating form of dementia.”

That’s a revolutionary development that could clear the way for other Alzheimer’s and dementia treatments which target amyloid plaque, proteins which manifest in the brains of dementia patients. This method of Alzheimer’s drug development has previously failed, with multiple companies abandoning late-stage clinical trials for treatments that target amyloid plaque.

But the broader question is whether the Biogen decision was truly based in science or the result of a concerted campaign by industry and affiliated patient groups, aided with the help of A-list celebrities such as Samuel L. Jackson, to push aducanumab past the regulatory finish line. An independent panel of advisers to the FDA overwhelmingly voted against the drug, saying clinical trial data did not provide strong evidence of its efficacy. There are also lingering questions about why two separate trials of aducanumab showed divergent results in study participants.

There’s another political twist to the story: The FDA currently lacks a permanent commissioner. Acting commissioner Janet Woodcock, a longtime agency veteran, has been part of several controversial drug approval decisions, including several which overturned the recommendations of independent advis

ers on new opioids and rare disease drugs such as Sarepta’s Duchenne muscular dystrophy therapy Exondys 51. The FDA isn’t obligated to follow independent experts’ advice but usually does. The approval of Biogen’s Alzheimer’s drug may well be the most dramatic departure from the practice to date.

In fact, the agency itself noted the controversy in its approval statement Monday: “The data included in the applicant’s submission were highly complex and left residual uncertainties regarding clinical benefit. There has been considerable public debate on whether Aduhelm should be approved,” it wrote.

“The Agency concluded that the benefits of Aduhelm for patients with Alzheimer’s disease outweighed the risks of the therapy.”

The regulatory process isn’t quite done, however, given the way aducanumab was approved—that is, through an accelerated approval process reserved for treatments for diseases where patients have few options. “Under the accelerated approval provisions, which provide patients earlier access to the treatment, the FDA is requiring a new randomized, controlled clinical trial to verify the drug’s clinical benefit. If the trial fails to verify clinical benefit, the FDA may initiate proceedings to withdraw approval of the drug,” said the Alzheimer’s Foundation of America in a statement. That new trial process can take years.

Biogen also announced that aducanumab will come with a list price of $56,000 per year, or $4,312 per infusion. While that will likely not be the out-of-pocket cost many patients pay following rebates, discounts, and financial assistance, it is still significantly higher than what watchdog organizations such as ICER have said would be a proper price.