---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-22-264177"
form_type: "8-K"
ticker: "SYBX"
cik: "0001527599"
company_name: "SYNLOGIC, INC."
filed_at: "2022-10-18T23:59:59+00:00"
generated_at: "2026-06-23T02:57:25.332832+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Synlogic reports positive Phase 2 PKU data; SYNB1934 advances to Phase 3 in H1 2023

## Summary
- Phase 2 Synpheny-1 study met primary endpoint: 60% response rate with 42% mean Phe reduction among responders.
- SYNB1934 showed -34% mean change from baseline in fasting plasma Phe; SYNB1618 showed -20%.
- All adverse events mild/moderate, primarily GI; no serious adverse events; 3 discontinuations due to GI AEs.
- Company confirms SYNB1934 as Phase 3 candidate; pivotal study expected to begin H1 2023.
- Data from 20 adult PKU patients; results consistent with adjunctive use with sapropterin.

## SEC filing metadata
- accession: 0001193125-22-264177
- form_type: 8-K
- ticker: SYBX
- cik: 0001527599
- company_name: SYNLOGIC, INC.
- filed_at: 2022-10-18T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1527599/000119312522264177/0001193125-22-264177-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1527599/000119312522264177/d387982d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-22-264177
- JSON: https://secwatch.observer/filing/0001193125-22-264177.json
- Plain text: https://secwatch.observer/filing/0001193125-22-264177.txt

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