---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-24-263398"
form_type: "8-K"
ticker: "ZYME"
cik: "0001937653"
company_name: "Zymeworks Inc."
filed_at: "2024-11-21T23:59:59+00:00"
generated_at: "2026-05-29T21:19:04.248400+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# FDA grants accelerated approval to Zymeworks' Ziihera for HER2+ BTC; $25M milestone earned

## Summary
- Ziihera (zanidatamab-hrii) approved for adults with previously-treated unresectable/metastatic HER2+ BTC.
- Approval based on 52% objective response rate and median DOR of 14.9 months from HERIZON-BTC-01 trial.
- Zymeworks earns $25M milestone from Jazz; eligible for up to $500M regulatory + $862.5M commercial milestones.
- Continued approval contingent on Phase 3 HERIZON-BTC-302 confirmatory trial.
- Zanidatamab also in Phase 3 trials for GEA (top-line PFS data Q2 2025) and mBC.

## SEC filing metadata
- accession: 0001193125-24-263398
- form_type: 8-K
- ticker: ZYME
- cik: 0001937653
- company_name: Zymeworks Inc.
- filed_at: 2024-11-21T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1937653/000119312524263398/0001193125-24-263398-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1937653/000119312524263398/d769907d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-24-263398
- JSON: https://secwatch.observer/filing/0001193125-24-263398.json
- Plain text: https://secwatch.observer/filing/0001193125-24-263398.txt

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