---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-23-029731"
form_type: "8-K"
ticker: "STRO"
cik: "0001382101"
company_name: "SUTRO BIOPHARMA, INC."
filed_at: "2023-06-26T23:59:59+00:00"
generated_at: "2026-06-13T16:56:21.157345+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Sutro Biopharma sells 4% royalty on Vaxcyte products to Blackstone for $140M upfront

## Summary
- Sold 4% royalty interest in Vaxcyte's future net sales (including VAX-24) to Blackstone Life Sciences.
- Received $140M upfront payment on June 23, 2023 from Blackstone.
- Eligible for up to $250M additional payments upon achieving return thresholds.
- Retains rights to discover and develop vaccines for non-infectious diseases, including cancer.
- Agreed to covenants on amending, assigning, and terminating the License Agreement with Vaxcyte.

## SEC filing metadata
- accession: 0000950170-23-029731
- form_type: 8-K
- ticker: STRO
- cik: 0001382101
- company_name: SUTRO BIOPHARMA, INC.
- filed_at: 2023-06-26T23:59:59+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/1382101/000095017023029731/0000950170-23-029731-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1382101/000095017023029731/stro-20230621.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-23-029731
- JSON: https://secwatch.observer/filing/0000950170-23-029731.json
- Plain text: https://secwatch.observer/filing/0000950170-23-029731.txt

## Key facts
- Material Agreements
  SUTRO BIOPHARMA, INC. entered into Purchase Agreement with affiliate of Blackstone Life Sciences valued at $140.0 million (effective 2023-06-21).
  - Action: entry
  - Agreement: asset purchase
  - Counterparty: affiliate of Blackstone Life Sciences
  - Value: $140.0 million
  - Effective: 2023-06-21
  source text: On June 21, 2023, Sutro Biopharma, Inc. (the “ Company ”) entered into a purchase and sale agreement (the “ Purchase Agreement ”) with an affiliate of Blackstone Life Sciences (“ Blackstone ”, and together with the Company, the “ Parties ”), pursuant to which the Company sold to Blackstone its 4% royalty, or revenue interest, in the potential future net sales of Vaxcyte Inc.’s (“ Vaxcyte ”) products, including VAX-24 (the “ Purchased Interest ”) under that certain Amended and Restated SutroVax Agreement, dated October 12, 2015, by and between the Company and Vaxcyte, as amended (the “ License Agreement ”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/1382101/000095017023029731/0000950170-23-029731-index.htm

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