The proposal, issued April 27, 2026, is not a final withdrawal order. TAVNEOS remains on the market unless the applicant removes it or the FDA commissioner orders that its approval be withdrawn.

The action places a treatment for a rare but serious disease at the center of questions about clinical-trial integrity, drug-safety monitoring and how patients and clinicians should evaluate treatment options while the agency’s process continues.

What the FDA found

According to the FDA, newly available information showed that unblinded personnel involved in the pivotal study manipulated study results. The agency also said the applicant did not disclose the original analysis to the FDA.

The FDA’s action includes a notice of opportunity for a hearing addressed to ChemoCentryx, which is an Amgen subsidiary. The hearing notice gives the applicant a chance to respond before the agency makes a final decision on the marketing authorization.

The agency separately issued a safety communication on March 31, 2026, identifying serious drug-induced liver injuries associated with TAVNEOS. The cases included vanishing bile duct syndrome and fatal outcomes.

The FDA’s summary does not provide a total number of affected patients or a confirmed total for the liver-injury cases. That means the proposal establishes the agency’s stated findings and safety concerns but does not, from the information available in the approved summary, quantify the full scope of the reported injuries.

What happens to the drug now

TAVNEOS was approved on Oct. 7, 2021. Its approved use was alongside glucocorticoids and other standard treatments for adults with severe active ANCA-associated vasculitis.

For now, the approval remains in force. The FDA has advised clinicians to discuss TAVNEOS and available alternatives with patients while the final marketing-status decision is pending. The agency has not directed patients, through the information summarized here, to stop or continue treatment without consulting a clinician.

If ChemoCentryx requests a hearing, the FDA commissioner will first decide whether to hold one. The commissioner would then decide whether the approval should be withdrawn. The April 27 proposal therefore begins a regulatory process rather than ending TAVNEOS’s U.S. availability immediately.

Why the proposal matters

The decision affects more than the status of one medicine. TAVNEOS was approved for use in a severe form of ANCA-associated vasculitis, making the FDA’s review relevant to patients who may be weighing the drug against alternatives and to clinicians responsible for discussing those choices.

It also tests the safeguards that support drug approval after a medicine reaches the market. The FDA’s stated concerns involve both the reliability of pivotal-study results and the disclosure of underlying analyses. Its liver-injury findings add a post-market safety dimension, including reports of vanishing bile duct syndrome and fatal outcomes.

The next known step is procedural: ChemoCentryx may request a hearing under the FDA notice, after which the commissioner would determine whether a hearing occurs and whether approval should ultimately be withdrawn. Until a final action or voluntary removal, TAVNEOS remains available in the United States.