StocksMedium•6 March 2026•
1 min read

Alexion Halts US Royalty Payments to Xencor for Ultomiris Drug

Key Facts

1Alexion has ceased making US royalty payments to Xencor related to the drug Ultomiris.
2Xencor is revising its revenue outlook for royalties following the payment halt.

Xencor Inc. (NASDAQ: XNCR) has announced that Alexion, a subsidiary of AstraZeneca, has ceased making royalty payments in the United States for the drug Ultomiris. This unexpected development has forced Xencor to revise its revenue outlook as it assesses the financial implications of the payment halt. These royalties constitute a significant portion of Xencor's projected cash flow, and their suspension introduces immediate uncertainty into the company's financial guidance. Analysts consider this move a bearish signal for the stock, as it may lead to protracted legal or commercial disputes. Xencor is currently evaluating its options under the existing licensing agreement to address the loss of income. Investors are expected to remain cautious until further clarity is provided regarding the duration and impact of this royalty dispute.