---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-22-026823"
form_type: "8-K"
ticker: "STRO"
cik: "0001382101"
company_name: "SUTRO BIOPHARMA, INC."
filed_at: "2022-12-20T23:59:59+00:00"
generated_at: "2026-06-21T01:37:43.514610+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Sutro grants Vaxcyte option to manufacture and source extract for vaccines; receives $22.5M upfront

## Summary
- Upfront payment of $22.5M: $7.5M in Vaxcyte common stock, $15M in cash.
- Option exercise triggers $75M cash payment in two installments; regulatory milestones up to $60M additional.
- Option period of five years, with potential acceleration on Vaxcyte change of control.
- Vaxcyte gains authorization to source cell-free extract from an independent CMO for its licensed products.
- Economic terms of existing agreements between Sutro and Vaxcyte remain unchanged.

## SEC filing metadata
- accession: 0000950170-22-026823
- form_type: 8-K
- ticker: STRO
- cik: 0001382101
- company_name: SUTRO BIOPHARMA, INC.
- filed_at: 2022-12-20T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 1.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1382101/000095017022026823/0000950170-22-026823-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1382101/000095017022026823/stro-20221219.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-22-026823
- JSON: https://secwatch.observer/filing/0000950170-22-026823.json
- Plain text: https://secwatch.observer/filing/0000950170-22-026823.txt

## Key facts
- Material Agreements
  SUTRO BIOPHARMA, INC. entered into Letter Agreement with Vaxcyte, Inc. valued at Upfront payment of $22.5 million ($7.5 million in shares and $15 million in cash) and potential mile (effective 2022-12-19).
  - Action: entry
  - Agreement: license
  - Counterparty: Vaxcyte, Inc.
  - Value: Upfront payment of $22.5 million ($7.5 million in shares and $15 million in cash) and potential mile
  - Effective: 2022-12-19
  source text: On December 19, 2022, Sutro Biopharma, Inc. (the “ Company ”) entered into a letter agreement (the “ Agreement ”) with Vaxcyte, Inc. (“ Vaxcyte ”) under which the Company granted to Vaxcyte (i) authorization to enter into an agreement with an independent alternate contract manufacturing organization (“ CMO ”) to source cell-free extract solely for the products it licensed from the Company, allowing Vaxcyte to have direct oversight over financial and operational aspects of the relationship with the CMO, and (ii) a right, but not an obligation, to obtain certain exclusive rights to internally manufacture and/or source extract from certain CMOs and the right to independently develop and make improvements to extract for use in connection with the exploitation of certain vaccine compositions (the “ Option ”). The Option is exercisable for five years following the effective date of the Agreement (the “ Option Period ”), subject to potential acceleration in the event of a change of control of
  evidence_url: https://www.sec.gov/Archives/edgar/data/1382101/000095017022026823/0000950170-22-026823-index.htm

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