The Medicines and Healthcare products Regulatory Agency (MHRA) said in a 1 September 2026 press release that it had completed its review of Avacopan Vifor (previously Tavneos) and determined that available evidence no longer supports a positive benefit-risk balance. The review followed information raising questions about the integrity and reliability of data from the pivotal clinical study behind the medicine's authorisation. After assessing the evidence, advice from the Commission on Human Medicines and representations from patients and healthcare professionals, the MHRA concluded the study can no longer be relied upon to demonstrate efficacy.

The MHRA informed the marketing authorisation holder of its decision to suspend use, supply and sale to new patients from 1 September 2026. Supply was to be permitted only to existing patients during a six-month managed withdrawal period, after which the MHRA intended to revoke the UK marketing authorisation on 1 March 2027. The holder guaranteed supply for that period. In the UK, the medicine, combined with a rituximab or cyclophosphamide regimen, is indicated for adults with severe, active granulomatosis with polyangiitis or microscopic polyangiitis.

MHRA Executive Director Julian Beach said patient safety is the agency's highest priority. Healthcare professionals were advised not to start treatment in new patients and to review those currently receiving it; patients were told not to stop treatment without first consulting their specialist. Existing risk minimisation advice, including liver function, white blood cell count and infection monitoring, continues to apply.