---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-160355"
form_type: "8-K"
ticker: "SYBX"
cik: "0001527599"
company_name: "SYNLOGIC, INC."
filed_at: "2023-06-05T23:59:59+00:00"
generated_at: "2026-06-14T07:19:54.231722+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Synlogic initiates Phase 3 PKU study SYNB1934, cuts workforce 21%

## Summary
- Initiated Synpheny-3 global pivotal Phase 3 trial of SYNB1934 for phenylketonuria (PKU), targeting ~150 patients.
- Primary endpoint: change in plasma phenylalanine after 4-week placebo-controlled randomized withdrawal.
- Workforce reduced by ~21%; expects $0.9M in severance costs in Q2/Q3 2023.
- Cash runway extended into H2 2024 by prioritizing SYNB1934 and SYNB1353 programs.
- Study design includes virtual/hybrid options; ages 18+ with potential expansion to 12+.

## SEC filing metadata
- accession: 0001193125-23-160355
- form_type: 8-K
- ticker: SYBX
- cik: 0001527599
- company_name: SYNLOGIC, INC.
- filed_at: 2023-06-05T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 2.05, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1527599/000119312523160355/0001193125-23-160355-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1527599/000119312523160355/d232864d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-160355
- JSON: https://secwatch.observer/filing/0001193125-23-160355.json
- Plain text: https://secwatch.observer/filing/0001193125-23-160355.txt

## Key facts
- Restructurings & Charges
  SYNLOGIC, INC. announced a restructuring with charges of approximately $0.9 million (approximately 21%).
  - Type: restructuring
  - Charge: approximately $0.9 million
  - Headcount: approximately 21%
  source text: On June 5, 2023, Synlogic, Inc. (the “Company”) announced that it is implementing a reduction in workforce designed to focus resources on advancing the Company’s clinical stage programs and research activities that support the current clinical pipeline and its ongoing collaboration with Roche. The realignment is estimated to reduce the Company’s workforce by approximately 21%. The Company expects to complete substantially all of the reduction in workforce by the end of the fiscal quarter ending June 30, 2023. The Company estimates that it will incur approximately $0.9 million of costs in connection with the reduction in workforce related to severance pay and other related termination benefits.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1527599/000119312523160355/0001193125-23-160355-index.htm

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