---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-038879"
form_type: "8-K"
ticker: "STRO"
cik: "0001382101"
company_name: "SUTRO BIOPHARMA, INC."
filed_at: "2025-03-13T23:59:59+00:00"
generated_at: "2026-05-24T20:39:25.476727+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Sutro restructures with 50% layoffs, deprioritizes luvelta; CEO Newell steps down, Jane Chung appointed

## Summary
- Jane Chung appointed CEO, replaces Bill Newell effective March 13, 2025; CFO and CMO also transitioning.
- Workforce reduced ~50%; luvelta (STRO-002) development halted; out-licensing sought.
- Cash, cash equivalents & marketable securities $316.9M as of Dec 31, 2024; cash runway into at least Q4 2026.
- Restructuring costs estimated $40-$45 million, largely in 2025; revenue $62M in FY2024 vs $153.7M in 2023.
- Three IND filings planned over next 3 years: STRO-004 (Tissue Factor ADC) expected 2H 2025, STRO-006 in 2026, dual-payload ADC in 2027.

## SEC filing metadata
- accession: 0000950170-25-038879
- form_type: 8-K
- ticker: STRO
- cik: 0001382101
- company_name: SUTRO BIOPHARMA, INC.
- filed_at: 2025-03-13T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 2.02, 2.05, 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1382101/000095017025038879/0000950170-25-038879-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1382101/000095017025038879/stro-20250313.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-038879
- JSON: https://secwatch.observer/filing/0000950170-25-038879.json
- Plain text: https://secwatch.observer/filing/0000950170-25-038879.txt

## Key facts
- Executive change
  William J. Newell resigned as Director at SUTRO BIOPHARMA, INC..
  - Action: resigned
  - Role: Director
  source text: resigned as a director of the Board, effective as of the Newell Separation Date
  evidence_url: https://www.sec.gov/Archives/edgar/data/1382101/000095017025038879/0000950170-25-038879-index.htm
- Executive change
  William J. Newell resigned as President and Chief Executive Officer at SUTRO BIOPHARMA, INC..
  - Action: resigned
  - Role: President and Chief Executive Officer
  source text: Mr. Newell ceased his role as the Company’s President and CEO, effective March 13, 2025
  evidence_url: https://www.sec.gov/Archives/edgar/data/1382101/000095017025038879/0000950170-25-038879-index.htm
- Executive change
  Jane Chung was appointed as Class II Director at SUTRO BIOPHARMA, INC..
  - Action: appointed
  - Role: Class II Director
  source text: The Board also appointed Ms. Chung as a Class II Director of the Company, effective as of the Newell Separation Date.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1382101/000095017025038879/0000950170-25-038879-index.htm
- Executive change
  Jane Chung was appointed as Chief Executive Officer at SUTRO BIOPHARMA, INC..
  - Action: appointed
  - Role: Chief Executive Officer
  source text: Effective as of the Newell Separation Date, the Board appointed Jane Chung, the Company’s President and Chief Operating Officer, to succeed Mr. Newell as Chief Executive Officer.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1382101/000095017025038879/0000950170-25-038879-index.htm
- Restructurings & Charges
  SUTRO BIOPHARMA, INC. announced a restructuring with charges of approximately $40 million to $45 million affecting luveltamab tazevibulin (luvelta) activities and internal GMP manufacturing facility (approximately 50%).
  - Type: restructuring
  - Charge: approximately $40 million to $45 million
  - Affected area: luveltamab tazevibulin (luvelta) activities and internal GMP manufacturing facility
  - Headcount: approximately 50%
  source text: The total cash payments and costs related to deprioritizing luvelta-related activities and reducing the workforce are estimated to be approximately $40 million to $45 million, with a significant majority of these amounts expected to be paid in 2025.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1382101/000095017025038879/0000950170-25-038879-index.htm

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