---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-010643"
form_type: "8-K"
ticker: "SYBX"
cik: "0001527599"
company_name: "SYNLOGIC, INC."
filed_at: "2023-01-19T23:59:59+00:00"
generated_at: "2026-06-20T13:07:00.140641+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Synlogic receives FDA Rare Pediatric Disease Designation for SYNB1934 in PKU

## Summary
- FDA granted RPDD for SYNB1934, a synthetic biotic candidate for phenylketonuria (PKU).
- Company plans to start Synpheny-3 pivotal Phase 3 study for SYNB1934 in H1 2023.
- Follows similar RPDD for SYNB1353 for homocystinuria (HCU) received in December 2022.
- Designation highlights the urgent need for new PKU treatment options in children.

## SEC filing metadata
- accession: 0001193125-23-010643
- form_type: 8-K
- ticker: SYBX
- cik: 0001527599
- company_name: SYNLOGIC, INC.
- filed_at: 2023-01-19T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1527599/000119312523010643/0001193125-23-010643-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1527599/000119312523010643/d457598d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-010643
- JSON: https://secwatch.observer/filing/0001193125-23-010643.json
- Plain text: https://secwatch.observer/filing/0001193125-23-010643.txt

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