Sutro Biopharma, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Basis of Presentation and Summary of Significant Accounting Policies (Policies)
Notes Tables
Notes Details

Organization and Principal Activities - Additional Information (Details)

v3.20.1

Organization and Principal Activities - Additional Information (Details)		12 Months Ended
	Feb. 28, 2020 USD ($)	Dec. 31, 2019 USD ($) Segment	Dec. 31, 2018 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Date of incorporation		Apr. 21, 2003
Headquartered in		South San Francisco
Headquartered in state		CA
Number of operating segments \| Segment		1
Accumulated deficit		$ 195,745,000	$ 150,328,000
Unrestricted cash, cash equivalents and marketable securities		$ 133,500,000
Substantial doubt about going concern, within one year		false
Loan and Security Agreement \| Oxford Finance LLC and Silicon Valley Bank \| Term A Loan \| Subsequent Event
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Term loan maximum borrowing capacity	$ 25,000,000.0
Borrowed amount	25,000,000.0
Repayment of outstanding principal amount	9,600,000
Maximum \| Loan and Security Agreement \| Oxford Finance LLC and Silicon Valley Bank \| Term Loans \| Subsequent Event
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Additional borrowing amount	5,000,000.0
Minimum
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Going concern period from issuance date of unaudited interim condensed financial statements		12 months
Minimum \| Loan and Security Agreement \| Oxford Finance LLC and Silicon Valley Bank \| Term B Loan \| Subsequent Event
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Upfront payment received	$ 50,000,000.0

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