On 5 June 2026, the Medicines and Healthcare products Regulatory Agency said it had opened a review of avacopan, marketed as Avacopan Vifor and previously known as Tavneos, after receiving information that raises questions about the integrity and reliability of the data from the pivotal clinical study that supported the medicine's licence approval. The notice does not announce an immediate change to the medicine's regulatory status, but it does place the underlying evidence base under formal scrutiny. (gov.uk) Avacopan is authorised in combination with a rituximab or cyclophosphamide regimen for adults with severe, active granulomatosis with polyangiitis or microscopic polyangiitis, both rare autoimmune conditions affecting small blood vessels. The electronic medicines compendium summary of product characteristics lists the product as a prescription-only medicine. (gov.uk)
The MHRA says the review will consider whether the new information changes what the pivotal study showed about avacopan's effectiveness and what that means for the overall benefit-risk balance of the product. In practical terms, the agency is testing whether the evidence base used at licensing still supports the medicine's authorised use. (gov.uk) That framing matters because the concern identified by the regulator is not limited to a routine safety update. The published notice points directly to the integrity and reliability of the pivotal study data, which makes the review as much about evidential validity as about day-to-day pharmacovigilance. (gov.uk)
The legal route is regulation 68 of the Human Medicines Regulations 2012. As the legislation sets out, the licensing authority may revoke, vary or suspend a UK marketing authorisation if it considers, among other things, that the product is harmful, that its positive therapeutic effects no longer outweigh its risks, that it lacks therapeutic efficacy, or that the application or material supplied with it is incorrect. (legislation.gov.uk) The MHRA's own wording links the present review to that test. It says the process is being undertaken under regulation 68 because the licensing authority may act where the material supplied no longer supports a positive benefit-risk balance for the product. (gov.uk)
For clinicians, the immediate position is continuity rather than withdrawal. The MHRA says the existing risk minimisation advice in the product information remains in force while the review is under way, and it reminds healthcare professionals to consider carefully the individual patient benefits and risks associated with avacopan. (gov.uk) The current summary of product characteristics states that treatment should be initiated and monitored by professionals experienced in granulomatosis with polyangiitis or microscopic polyangiitis. It also sets out the active monitoring framework already attached to use of the medicine, including liver function tests, white blood cell monitoring and assessment for serious infection, and notes that avacopan is subject to additional monitoring. (medicines.org.uk)
The product information goes further on the operational detail. It states that treatment must be clinically re-assessed and temporarily stopped if liver enzymes rise beyond stated thresholds, if significant leukopenia, neutropenia or lymphopenia develops, or if a patient has an active serious infection requiring hospitalisation or prolonged hospitalisation. (medicines.org.uk) That means the regulatory review does not replace existing prescribing controls; it sits alongside them. Until the MHRA reaches a conclusion, the current licence conditions and monitoring expectations remain the working framework for specialist teams using the medicine. (gov.uk)
For patients, the public advice remains deliberately narrow. The MHRA says patients should not stop treatment without consulting their healthcare professional, which indicates that no general stop notice has been issued at this stage. The agency also says suspected adverse reactions should continue to be reported through the Yellow Card scheme. (gov.uk) The next step is the regulator's conclusion on whether the new information changes the benefit-risk position enough to justify action under regulation 68. If that threshold is met, the legal framework allows variation, suspension or revocation of the marketing authorisation; if it is not met, current arrangements can remain in place. Until that decision is published, avacopan remains authorised and the existing product information continues to govern use. (legislation.gov.uk)