---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-171784"
form_type: "8-K"
ticker: "XOMA"
cik: "0000791908"
company_name: "XOMA Royalty Corp"
filed_at: "2023-06-22T23:59:59+00:00"
generated_at: "2026-06-13T19:31:06.045470+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# XOMA acquires LadRx royalty/milestone rights for arimoclomol and aldoxorubicin for $5M upfront

## Summary
- Acquired 100% of LadRx's royalty and milestone rights for arimoclomol (NPC) and aldoxorubicin (ImmunityBio).
- Paid $5M upfront; additional milestone payments of up to $6M may be required.
- Arimoclomol rights: $52.6M net milestones and mid-single-digit royalty from Zevra.
- Aldoxorubicin rights: mid-single-digit to mid-teens royalties and up to $343M milestones from ImmunityBio.
- Agreements include customary covenants, representations, and indemnification.

## SEC filing metadata
- accession: 0001193125-23-171784
- form_type: 8-K
- ticker: XOMA
- cik: 0000791908
- company_name: XOMA Royalty Corp
- filed_at: 2023-06-22T23:59:59+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 1.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/791908/000119312523171784/0001193125-23-171784-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/791908/000119312523171784/d468159d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-171784
- JSON: https://secwatch.observer/filing/0001193125-23-171784.json
- Plain text: https://secwatch.observer/filing/0001193125-23-171784.txt

## Key facts
- Material Agreements
  XOMA Royalty Corp entered into Assignment and Assumption Agreement with LadRx Corporation valued at $5 million upfront, up to $6 million in potential milestone payments (effective 2023-06-21).
  - Action: entry
  - Agreement: license
  - Counterparty: LadRx Corporation
  - Value: $5 million upfront, up to $6 million in potential milestone payments
  - Effective: 2023-06-21
  source text: On June 21, 2023, XOMA (US) LLC (“XOMA”), a wholly-owned subsidiary of XOMA Corporation (the “Company”), entered into an Assignment and Assumption Agreement (the “Assignment Agreement”) and a Royalty Purchase Agreement (the “Royalty Purchase Agreement” and together with the Assignment Agreement, the “Agreements”) with LadRx Corporation (“LadRx”), a Delaware corporation.
  evidence_url: https://www.sec.gov/Archives/edgar/data/791908/000119312523171784/0001193125-23-171784-index.htm
- Material Agreements
  XOMA Royalty Corp entered into Royalty Purchase Agreement with LadRx Corporation valued at $5 million upfront, up to $6 million in potential milestone payments (effective 2023-06-21).
  - Action: entry
  - Agreement: license
  - Counterparty: LadRx Corporation
  - Value: $5 million upfront, up to $6 million in potential milestone payments
  - Effective: 2023-06-21
  source text: On June 21, 2023, XOMA (US) LLC (“XOMA”), a wholly-owned subsidiary of XOMA Corporation (the “Company”), entered into an Assignment and Assumption Agreement (the “Assignment Agreement”) and a Royalty Purchase Agreement (the “Royalty Purchase Agreement” and together with the Assignment Agreement, the “Agreements”) with LadRx Corporation (“LadRx”), a Delaware corporation.
  evidence_url: https://www.sec.gov/Archives/edgar/data/791908/000119312523171784/0001193125-23-171784-index.htm

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