A narrow vote for approval

In May twenty twenty-one, the FDA asked an advisory committee whether to approve Tavneos, an experimental drug for a rare autoimmune vasculitis. The committee voted narrowly to recommend approval despite concerns about the trial's design.

FDA greenlights the drug

The FDA followed the advisory committee's recommendation and approved Tavneos on October seven, twenty twenty-one. The drug, made by California biotechnology company ChemoCentryx, was marketed to reduce steroid use in vasculitis patients.

A costly acquisition

A year after approval, Amgen, one of the world's largest pharmaceutical companies, acquired ChemoCentryx for nearly four billion dollars.

Lawsuit uncovers alleged fraud

A shareholder lawsuit against ChemoCentryx uncovered evidence that company employees manipulated trial data. The original analysis showed Tavneos patients had not achieved better remission rates than those receiving standard treatment.

How the data was altered

After unblinding the trial data, ChemoCentryx employees selected patients for reassessment, or readjudication. The FDA alleges the patients were cherry-picked to produce results needed for approval. ChemoCentryx did not disclose this to the FDA.

FDA proposes withdrawal

In April of this year, the FDA issued a letter proposing that Tavneos be withdrawn from the US market, citing serious liver injuries and arguing the drug lacks substantial evidence that it works.

Global fallout begins

The New England Journal of Medicine retracted the Tavneos trial paper.The European Union removed the drug from the market.The United Kingdom announced it would do the same.

FDA director's stark assessment

Tracy Beth Høeg, acting director of the FDA's Center for Drug Evaluation and Research, wrote that ChemoCentryx swindled billions of dollars.The drug has been linked to eight deaths and dozens of hospitalizations.

“This can be a deadly drug, and we don't know if it works.”

Amgen contests the findings

Amgen submitted a one hundred four-page document to the FDA arguing that the totality of the evidence supports continued availability of Tavneos.The company said ChemoCentryx's actions were unfortunate but do not amount to data manipulation.

“the totality of the evidence supports the continued availability of TAVNEOS.”

Amgen's defense of the reassessment

Amgen maintains that no underlying data were changed and the reassessment was conducted to correct a small number of errors. The company argues ChemoCentryx was not legally required to disclose the readjudication to the FDA.

Chloe Cusano's story

Chloe Cusano, a twenty-year-old college student, was diagnosed with ANCA-associated vasculitis in December.Steroids caused severe side effects including forty pounds of weight gain, emotional swings, insomnia and nightmares.

Real-world evidence supports the drug

Eric Roberts, an epidemiologist at the University of California, San Francisco, co-authored an independent registry study of Tavneos.

“This appears to be an efficacious medication.”

Critics demand peer review

Joshua Skydel, a clinical fellow in rheumatology at Yale New Haven Hospital, argues Tavneos should not remain on the market.Several studies Amgen pointed to have yet to be published.

“I'd at least like to see them go through peer review before hanging my hat on them.”

Amgen behind on post-approval studies

At the time of Tavneos approval, the FDA requested additional post-marketing studies.Amgen has fallen behind on deadlines for those studies.Skydel noted this highlighted how drugs reach the market with open questions that remain unanswered.

FDA's broader concern

In its April letter, the FDA argued that withdrawing Tavneos is critical to protect public health and the integrity of the drug approval process.

The trust question

Walter Kraft, who voted to approve Tavneos, now worries about knock-on effects.The clinical trial system is built on a level of trust.

“The clinical trial system is built on a level of trust.”

The FDA's legal path forward

Patricia Zettler, a law professor at The Ohio State University, explained the FDA's authority to withdraw approval.The agency must give notice and offer the manufacturer a public hearing.

Amgen could sue if approval is withdrawn

If the FDA withdraws Tavneos approval and Amgen disagrees, the company could sue the agency. This leaves patients and physicians in a potentially protracted state of uncertainty about whether Tavneos actually works.