Amgen's Tavneos Faces Regulatory Setback Amid Efficacy Concerns

Amgen's rare-disease drug Tavneos (avacopan) is facing a significant regulatory setback in the UK, where it has been suspended for new patients and will be fully withdrawn by March 2027. The decision follows similar actions in Europe and a proposed US withdrawal.

Tavneos treats adults with severe forms of ANCA-associated vasculitis, a group of rare autoimmune diseases that can damage organs such as the kidneys and lungs. Amgen acquired the drug through its $3.7 billion purchase of ChemoCentryx in 2022.

The UK Medicines and Healthcare Products Regulatory Agency (MHRA) has stated that the pivotal study supporting Tavneos can no longer be relied upon to demonstrate efficacy, leading to the suspension and eventual withdrawal of the drug.

Amgen spokespersons have expressed disagreement with the MHRA's decision, citing concerns about the impact on rare-disease patients. The company generated $150 million in Q2 sales from Tavneos, up 36% year over year, but the financial impact is expected to be manageable for now.