---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-030011"
form_type: "8-K"
ticker: "PHAT"
cik: "0001783183"
company_name: "Phathom Pharmaceuticals, Inc."
filed_at: "2023-02-09T23:59:59+00:00"
generated_at: "2026-06-19T20:43:26.977868+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Phathom receives FDA complete response letters for vonoprazan NDAs due to nitrosamine impurity

## Summary
- CRL for erosive esophagitis NDA and H. pylori post-approval supplement, citing impurity N-nitroso-vonoprazan (NVP).
- FDA requests additional stability data showing NVP remains below acceptable intake throughout shelf life; no other deficiencies.
- Phathom implemented mitigation measures and expects to meet with FDA in Q1 2023 to discuss resubmission timeline.
- This follows January 2023 announcement; delays potential approval and commercial launch of vonoprazan products.

## SEC filing metadata
- accession: 0001193125-23-030011
- form_type: 8-K
- ticker: PHAT
- cik: 0001783183
- company_name: Phathom Pharmaceuticals, Inc.
- filed_at: 2023-02-09T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1783183/000119312523030011/0001193125-23-030011-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1783183/000119312523030011/d426711d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-030011
- JSON: https://secwatch.observer/filing/0001193125-23-030011.json
- Plain text: https://secwatch.observer/filing/0001193125-23-030011.txt

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