Amgen baulks at FDA request to withdraw Tavneos

Amgen confirmed on its fourth-quarter results call that it has resisted a request by the FDA to withdraw its drug for ANCA-associated vasculitis, Tavneos, from the US market.

The FDA made its request in January for sales of Tavneos to be suspended, shortly before the EMA in Europe started a review of the oral complement C5 inhibitor in response to concerns about 'data integrity' in the ADVOCATE trial that supported regulatory approvals.

Tavneos (avacopan) is used to treat two forms of ANCA-associated vasculitis – granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) – and is one of Amgen's fastest-growing drugs, with sales growing 62% last year to reach $459 million. Amgen added the drug to its portfolio in 2022 when it bought ChemoCentryx in a $3.7 billion deal.

On Amgen's call, the company's head of R&D, Jay Bradner, said the FDA's request for a voluntary withdrawal on 16th January came as a surprise and resulted from "concerns raised about a process followed by ChemoCentryx to readjudicate primary endpoint results for nine of the 331 patients" in the ADVOCATE trial.

"ANCA-associated vasculitis is a group of very serious, rare, and destructive inflammatory illnesses that target blood vessels and can therefore damage vital organs like the kidneys, lungs, skin, nerves, and even the heart," said Bradner.

Prior to Tavneos' approval, treatment was with cyclophosphamide chemotherapy with azathioprine and rituximab, accompanied by long-term steroid use, which was associated with significant side effects, he added.

"We're in discussions with FDA, and we'll answer questions as we talk with them," Bradner told participants on the call.

Meanwhile, Amgen's chief executive, Robert Bradway, said that while Tavneos is a "very small product in our portfolio relative to the other things we have going on," it is nevertheless an "important and effective medicine based on clinical data, real-world evidence, and its favourable benefit-risk profile."

When the EMA announced its review of the drug, it said the handling of some data in the ADVOCATE study "which may have impacted the findings on the medicine's effectiveness."

Tavneos was approved by the FDA in 2021, despite earlier scepticism at the FDA about the design of the phase 3 trial, and an advisory committee meeting that was split down the middle on the question of whether the drug's efficacy data supported approval.

The comments on the FDA's request came as Amgen reported fourth-quarter revenues up 9% to $9.9 billion, ahead of analyst expectations, with predictions that it would make $37 to $38.4 billion in 2026, up from $36.8 billion in 2025.

The company has high hopes for MariTide (maridebart cafraglutide), a drug for obesity that could be dosed as infrequently as once every three months, and is currently in six phase 3 trials due to read out in 2027.