Amgen Shares Fall 2.1% Over Tavneos Risks

Amgen stock fell 2.1% on May 16, 2026 after Kissei warned of severe liver injury linked to Tavneos.
Kissei reported 20 fatal cases in Japan, including 13 deaths from Vanishing Bile Duct Syndrome, with 22 severe cases among 8,503 patients.
FDA proposed withdrawing U.S. approval on April 27, 2026, citing lack of efficacy evidence and false statements; EMA also began a review.
Kissei's fiscal year 2026 sales of Tavneos were 11.524 billion yen, while the drug’s Japanese approval remains active pending regulator discussions.