Amgen Faces Major Blow to Rare-Disease Drug
One regulatory setback is starting to look much broader
Moz Farooque
09/02/2026 09:08
Summary
- U.K. regulators suspended Tavneos and plan full withdrawal in 2027
Amgen AMGNis facing a widening regulatory threat to rare-disease drug Tavneos, after the U.K. suspended its use for new patients and set a path toward full withdrawal in March 2027. The decision follows similar action in Europe and a proposed U.S. withdrawal, raising the risk that a fast-growing product could effectively disappear from several major markets
Tavneos, or avacopan, treats adults with severe forms of ANCA-associated vasculitis, a group of rare autoimmune diseases that inflame small blood vessels and can damage organs including the kidneys and lungs. Amgen acquired the drug through its $3.7 billion purchase of ChemoCentryx in 2022
The U.K. Medicines and Healthcare Products Regulatory Agency said the pivotal study supporting Tavneos could no longer be relied upon to demonstrate efficacy. New patients cannot receive the drug beginning September 1, while existing patients have a six-month transition period before the agency intends to revoke authorization on March 1, 2027
“We disagree with the MHRA’s decision to withdraw Tavneos from the UK market and are deeply concerned about the impact this decision may have on rare-disease patients,” an Amgen spokesperson said
The financial impact is manageable for now but increasingly relevant. Tavneos generated $150 million in Q2 sales, up 36% year over year, compared with Amgen’s total quarterly revenue of $10.1 billion. Full-year 2025 Tavneos sales reached $459 million, up 62%
The bigger issue is regulatory contagion. The FDA has already proposed withdrawing Tavneos in the U.S., citing concerns about the reliability of efficacy data and new safety issues, including serious liver injury. The drug remains available while that process continues
Investors Takeaway
The FDA proceeding is now the critical catalyst. Amgen submitted additional analyses in July and requested a hearing as it fights to preserve U.S. approval
Investors should watch for the FDA’s decision, further international regulatory actions and changes to Tavneos sales. Because Tavneos represents only a small portion of Amgen’s overall revenue, an eventual withdrawal would not threaten the company’s core financial profile. But losing a rapidly growing rare-disease asset across multiple markets would weaken the return on the ChemoCentryx acquisition and increase scrutiny of Amgen’s broader rare-disease strategy
Disclosures
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