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How an unproven Alzheimer’s drug got approved

The process leading to approval of Biogen Inc.'s Alzheimer's disease therapy took several unusual turns, including a decision for the FDA to work far more closely with Biogen than is typical in a regulatory review, a New York Times examination has found.
The process leading to approval of Biogen Inc.'s Alzheimer's disease therapy took several unusual turns, including a decision for the FDA to work far more closely with Biogen than is typical in a regulatory review, a New York Times examination has found.Adam Glanzman/Bloomberg

Two months before the Food and Drug Administration’s deadline to decide whether to approve Biogen’s controversial Alzheimer’s drug aducanumab, a council of senior agency officials resoundingly agreed that there wasn’t enough evidence it worked.

The council, a group of 15 officials who review complex issues, concluded that another clinical trial was necessary before approving the drug. Otherwise, one council member noted, approval could “result in millions of patients taking aducanumab without any indication of actually receiving any benefit, or worse, cause harm,” according to minutes of the meeting, obtained by The New York Times.

“It is critical that the decision be made from a place of certainty,” the minutes said.

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The session, whose details have not been reported before, represented at least the third time that proponents of approving aducanumab in the FDA had received a clear message that the evidence did not convincingly show the drug could slow cognitive decline.

On June 7, the FDA greenlighted the drug anyway — a decision that has been met with scathing rebuke from many Alzheimer’s experts and other scientists and calls for investigations into how the agency approved a treatment that has little evidence it helps patients.

How and why the FDA went ahead and approved the drug — an intravenous infusion, marketed as Aduhelm, that the company has since priced at $56,000 a year — has become the subject of intense scrutiny. Two congressional committees are investigating the approval and the price. Much is still unknown, but an examination by the Times has found that the process leading to approval took several unusual turns, including a decision for the FDA to work far more closely with Biogen than is typical in a regulatory review.

Allegations about the collaboration prompted the FDA to conduct an internal inquiry after a consumer advocacy group called for an inspector general’s investigation, according to documents reviewed by the Times. The agency has not disclosed the inquiry.

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Though the decision was considered one of the agency’s most consequential and controversial in years, its leader, Dr. Janet Woodcock, the acting commissioner, was not involved in the deliberations and left the final ruling to the head of the center responsible for drug applications, the agency confirmed.

In written responses to questions from the Times, the FDA defended its decision to approve the drug — the first for Alzheimer’s in 18 years.

“The agency did not lower its standards,” the FDA said, adding, “and at no time considered doing so.”

The decision, the agency said, was “informed by science, medicine, policy, and judgment, in accordance with applicable legal and regulatory standards.”

In written answers to questions, Biogen said, “Biogen stands 100% behind Aduhelm and the clinical data that supported its approval.”

Facing mounting pressure, Woodcock recently called for an inspector general to investigate the agency’s approval process. Woodcock has publicly acknowledged “process problems,” but has not described what those problems were.

“This incident has shaken FDA integrity quite significantly,” said Wayne Pines, a former FDA senior official who has written histories about the agency. “The FDA is obligated to be sure that all stones are turned over, that every avenue is pursued to make sure that this was a decision that was made on the basis of scientific judgment and not on the basis of anything else.”

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In announcing its approval in June, the FDA acknowledged there was not sufficient evidence that the drug would help patients. Instead, it said it was greenlighting Aduhelm under a program called “accelerated approval,” which allows the authorization of drugs without persuasive proof of benefit if they are for serious diseases with few treatment options and if the drug affects part of the disease’s biology (known as a biomarker) in a way that is “reasonably likely to predict clinical benefit.”

The reason the agency gave — that the drug reduces a key protein that clumps into plaques in the brains of people with Alzheimer’s — is one that the agency official leading the aducanumab review had said in an earlier public meeting would not be used. Many Alzheimer’s experts say there is not nearly enough evidence that reducing the protein, amyloid, slows memory and thinking problems.

Many of the questions surrounding the approval of the drug have centered on the close working relationship the FDA and Biogen seemed to have during the application process. That included meeting several times a week in the summer of 2019 to jointly assess the data and chart a path forward, as well as a joint Biogen-FDA presentation to a committee of independent experts.

After receiving letters in December and January from the consumer advocacy group Public Citizen calling for an inspector general’s investigation of the collaboration, the FDA began an internal review focusing on the issue.

The inquiry took place during the spring, as the decision deadline on the drug loomed, and was conducted by an office in the Center for Drug Evaluation and Research. The center includes the office that led the aducanumab assessment. Public Citizen said it was not informed that the inquiry was taking place. Biogen said the FDA had not contacted the company in the inquiry.

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It is unclear what the internal review concluded. Michael Felberbaum, a spokesperson for the FDA, said the agency would have no comment while the issue of close collaboration is the subject of external investigations.

The approval was the culmination of a roller-coaster journey for aducanumab, which seemed to be dead when the trials were aborted in March 2019. Less than two months later, Biogen decided that because its subsequent analysis had found a slight benefit for patients on the high dose in one trial, it would revive its effort to get the drug approved.

That May, Dr. Al Sandrock, Biogen’s chief medical officer, scheduled an informal meeting with Dr. Billy Dunn, director of the FDA office that reviews Alzheimer’s drugs, at a neurology conference they both attended. At the meeting, first reported by the medical news organization STAT and confirmed by the Times, Sandrock showed the regulator some data underlying the new analysis.

The discussion led to a formal meeting several weeks later on the FDA campus. There, according to minutes of the meeting, Biogen and Dunn’s team decided that “it is imperative that extensive resources be brought to bear on achieving a maximum understanding of the existing data” on aducanumab.

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“Given the wholly unique situation that is the current state of the aducanumab development program,” the minutes say, “further analyses would best be conducted as part of a bilateral effort involving the agency and sponsor, i.e. through a ‘workstream’ or ‘working group’ collaboration.”

While aducanumab was in trials, Dunn and Samantha Budd Haeberlein, who oversaw the drug’s clinical development for Biogen, worked together on several other projects, interactions that some scientists, former FDA officials, and former Biogen employees said they thought blurred the expected boundary between a regulator and an official of a company in that regulator’s purview.

Last November, Biogen and Dunn’s team presented a joint review to an advisory committee of independent experts outside the agency who were tasked with voting on whether aducanumab was ready for approval. Usually, a company and FDA reviewers give separate presentations.

The joint presentation asserted that there was “substantial evidence of effectiveness to support approval” and described the single positive trial as “exceptionally persuasive.”

That was not the conclusion of every FDA division. The agency’s biostatistical office had reached an opposite assessment, writing in a separate review presented to the committee that “there is no compelling, substantial evidence of treatment effect or disease slowing.”

At the end of the daylong meeting, the advisory committee overwhelmingly agreed with the biostatistical assessment. To the question of whether there was enough evidence the drug would help patients, 10 members of the panel voted no and one was uncertain. There were no yes votes.

For months after the advisory committee meeting, Dunn and his team continued to work toward conventional approval of the drug.

But when the case was presented to the agency’s Medical Policy and Program Review Council, meeting on March 31 and April 7, the vast majority of the 15 members said the evidence did not meet the threshold for “instilling public confidence in the usefulness of the drug,” according to the minutes.

The idea of accelerated approval came up briefly toward the end, raised by Dr. Rick Pazdur, head of FDA’s oncology center, who was not a council member. It was not discussed in detail, but after the meeting, given the council’s rejection of standard approval, accelerated approval appeared to be the only way to make the drug available.

On April 26, Dr. Patrizia Cavazzoni, Dunn’s boss and director of the Center for Drug Evaluation and Research, led a smaller meeting about accelerated approval, which had never been used for Alzheimer’s drugs.

In fact, the FDA’s most recent guidance for Alzheimer’s drugs, issued by Dunn in 2018, says “the standard for accelerated approval” had not yet been met for the disease, “despite a great deal of research.” The guidance says that is because “there is unfortunately at present no sufficiently reliable evidence” that attacking amyloid plaques or other biomarkers of Alzheimer’s “would be reasonably likely to predict clinical benefit.”

At the April 26 meeting, Cavazzoni invited two officials not involved with neurological drugs who had used accelerated approval frequently: Pazdur and Dr. Peter Marks, the top vaccine regulator. They and Cavazzoni voted to grant such approval to aducanumab, as did Dr. Issam Zineh, director of the Office of Pharmacology, and Dr. Jacqueline Corrigan-Curay, who led the internal review of the FDA-Biogen collaboration.

The director of the office of translational sciences, Dr. ShaAvhrée Buckman-Garner — who supervises both the pharmacology and biostatistics offices — did not vote yes or no, saying she understood both arguments. The only clear no vote, FDA documents say, was the director of the office of biostatistics, Dr. Sylva Collins, “stating her belief that there is insufficient evidence to support accelerated approval or any other type of approval.”

On April 28, Biogen was told that aducanumab was now being considered for accelerated approval instead of standard approval, according to documents obtained by the Times.

The documents also show that Biogen submitted draft language for a label stating which patients should be eligible for the treatment, a common step in the final stages of a drug review for possible approval. Up until about a week before approval was announced, the label listed “contraindications” — medical conditions that should preclude patients from getting the drug. The final approval label, however, has only one word under contraindications: “None.”

The FDA said it does not comment on labeling negotiations. Biogen said that after “thoughtful consideration,” the conclusion was that it should be up to “the treating physician in the real-world” to decide which patients receive the drug.

Another change was made to the proposed label. Before approval, it said the drug’s purpose was “to delay clinical decline in patients with Alzheimer’s disease.”

But after a comment was put in the margin, the language was changed to “for the treatment of Alzheimer’s disease.” The note said the FDA’s office of prescription drug promotion “is concerned with the promotional implication of the phrase ‘to delay clinical decline’ considering that this product is being approved under accelerated approval.”

“In a promotional context,” the note cautioned, “the phrase suggests a guarantee of efficacy.”