---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-22-012215"
form_type: "8-K"
ticker: "STRO"
cik: "0001382101"
company_name: "SUTRO BIOPHARMA, INC."
filed_at: "2022-06-28T23:59:59+00:00"
generated_at: "2026-06-24T22:36:21.693104+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Sutro Biopharma enters $90M upfront license deal with Astellas for ADCs up to 3 targets

## Summary
- Astellas pays $90M upfront; Sutro eligible for up to $422.5M in milestones plus tiered royalties (low double-digit to mid-teen %).
- Sutro can elect US cost/profit sharing on any product candidate, replacing royalties in the US.
- Deal covers up to 3 biological targets selected by Astellas; Sutro handles preclinical development.
- Termination includes Astellas' convenience termination on 30 days' notice and mutual termination for material breach.

## SEC filing metadata
- accession: 0000950170-22-012215
- form_type: 8-K
- ticker: STRO
- cik: 0001382101
- company_name: SUTRO BIOPHARMA, INC.
- filed_at: 2022-06-28T23:59:59+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 1.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1382101/000095017022012215/0000950170-22-012215-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1382101/000095017022012215/stro-20220627.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-22-012215
- JSON: https://secwatch.observer/filing/0000950170-22-012215.json
- Plain text: https://secwatch.observer/filing/0000950170-22-012215.txt

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