---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-22-045517"
form_type: "8-K"
ticker: "PTGX"
cik: "0001377121"
company_name: "Protagonist Therapeutics, Inc"
filed_at: "2022-04-13T23:59:59+00:00"
generated_at: "2026-06-26T07:37:33.340345+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# FDA intends to rescind Breakthrough Therapy Designation for rusfertide; PN-943 Ph2 data due mid-May 2022

## Summary
- FDA notified Protagonist of intent to rescind Breakthrough Therapy Designation for rusfertide in polycythemia vera; company requesting meeting to appeal.
- PN-943 Phase 2 top-line data for ulcerative colitis expected in first half of Q2 2022 (by mid-May 2022).
- Rusfertide Phase 3 VERIFY study screening underway; no anticipated changes to development plan or timelines.
- Observed malignancies in rusfertide-treated patients explained; stopping rules align with background rates in PV population.
- Fast Track and Orphan Drug designations for rusfertide remain active.

## SEC filing metadata
- accession: 0001104659-22-045517
- form_type: 8-K
- ticker: PTGX
- cik: 0001377121
- company_name: Protagonist Therapeutics, Inc
- filed_at: 2022-04-13T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1377121/000110465922045517/0001104659-22-045517-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1377121/000110465922045517/tm2212619d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-22-045517
- JSON: https://secwatch.observer/filing/0001104659-22-045517.json
- Plain text: https://secwatch.observer/filing/0001104659-22-045517.txt

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