The UK's health regulator has suspended the use, supply and sale of Avacopan Vifor, previously known as Tavneos, for new patients from Sept. 1, the watchdog said Tuesday.

The Medicines and Healthcare products Regulatory Agency said available evidence no longer supports a positive benefit-risk balance for the medicine, which is used to treat some rare autoimmune diseases affecting small blood vessels.

Tavneos was originally developed by ChemoCentryx, which was acquired by Amgen (AMGN) in 2022, according to Amgen's website.

The regulator said it reached its decision after reviewing all available evidence, advice from the Commission on Human Medicines, and feedback from patients and healthcare professionals.

The supply will be allowed to existing patients during a six-month managed withdrawal period to allow safe alternative treatment options, the regulator said.