EU Regulator Recommends Revoking Approval for Amgen's Tavneos

The European Union's regulatory authority, specifically the Committee for Medicinal Products for Human Use (CHMP), has recommended revoking the marketing authorization for AMGN (Amgen)'s rare-disease drug Tavneos. This decision reverses the CHMP's previous endorsement of Tavneos and comes ahead of a related United States Food and Drug Administration (FDA) hearing.

As a result, Amgen's shares are at risk. Although broader market fluctuations are also affecting the stock, this EU reversal is a key company-specific factor in the current situation.

Tavneos (avacopan) is approved to treat adults with severe, active granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA), two rare forms of ANCA-associated vasculitis, used in combination with standard immunosuppressive therapy. The CHMP's review centered on data-integrity concerns, which ultimately led to its recommendation to revoke the drug's authorization.

Regulatory reversals of this kind are uncommon and can dent both near-term sales and reputation. Investors will watch whether Amgen can address the CHMP's concerns, how the parallel FDA review unfolds, and what the decision implies for the drug's standing in other markets.