---
schema_version: "secwatch.filing_event.v1"
accession: "0001326732-26-000021"
form_type: "8-K"
ticker: "XNCR"
cik: "0001326732"
company_name: "Xencor Inc"
filed_at: "2026-03-04T23:59:59+00:00"
generated_at: "2026-05-15T21:32:59.959052+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Alexion refuses further US Ultomiris royalties; Xencor disputes, cuts revenue forecast

## Summary
- Alexion informed Xencor it will not pay additional US royalties on Ultomiris and will cease future US payments.
- Xencor previously expected $100-$120M in additional US royalties through 2028; now considers that revenue at risk.
- Ex-US royalty payments from Alexion continue unchanged, per Xencor's CEO.
- Xencor updates 2026 year-end cash guidance to $380-400M; operating runway extended into mid-2028.
- Xencor is actively evaluating options and disagrees with Alexion's position.

## SEC filing metadata
- accession: 0001326732-26-000021
- form_type: 8-K
- ticker: XNCR
- cik: 0001326732
- company_name: Xencor Inc
- filed_at: 2026-03-04T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1326732/000132673226000021/0001326732-26-000021-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1326732/000132673226000021/xncr-20260304.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001326732-26-000021
- JSON: https://secwatch.observer/filing/0001326732-26-000021.json
- Plain text: https://secwatch.observer/filing/0001326732-26-000021.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.