Yes. Sutro Biopharma filed 3 WARN notices to cut 54 jobs in South San Francisco, California, with the layoffs effective Sep 30, 2025. The most recent was filed Sep 29, 2025 under the federal WARN Act.
54 roles affected across 3 filings.
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Canary status: ListeningEVIDENCE-BASED · NOT A PREDICTION
1 SEC restructuring disclosure (8-K Item 2.05)
CanaryWhistle's own assessment, computed from the public filings listed on this page. It is a read of hiring and workforce activity, not a statement about Sutro Biopharma's solvency or creditworthiness. Not a credit rating and not financial advice. See our sources and method.
Filing history
Sutro Biopharma has filed 3 WARN notices in 2025, cutting 54 jobs in total. Activity picked back up in the last 12 months (54 jobs) after a quiet prior year.
54
2025
Corporate signalsSEC · PBGC · PRIMARY SOURCES
Material corporate events on record for Sutro Biopharma, beyond the WARN notice, that fill in the wider story of a company under pressure. Each links to its official source. No other layoff tracker connects these.
Sep 29, 2025RestructuringSEC Form 8-K, Item 2.05, filed 2025-09-29 by SUTRO BIOPHARMA, INC. (STRO).SEC filing →
Jun 2, 2025Executive ChangeSEC Form 8-K, Item 5.02, filed 2025-06-02 by SUTRO BIOPHARMA, INC. (STRO).SEC filing →
Apr 14, 2025Executive ChangeSEC Form 8-K, Item 5.02, filed 2025-04-14 by SUTRO BIOPHARMA, INC. (STRO).SEC filing →
Mar 13, 2025RestructuringSEC Form 8-K, Item 2.05, filed 2025-03-13 by SUTRO BIOPHARMA, INC. (STRO).SEC filing →
Mar 13, 2025Executive ChangeSEC Form 8-K, Item 5.02, filed 2025-03-13 by SUTRO BIOPHARMA, INC. (STRO).SEC filing →
Aug 12, 2024Executive ChangeSEC Form 8-K, Item 5.02, filed 2024-08-12 by SUTRO BIOPHARMA, INC. (STRO).SEC filing →
Yes. Sutro Biopharma filed 3 WARN notices to cut 54 jobs in South San Francisco, California, with the layoffs effective Sep 30, 2025. The most recent was filed Sep 29, 2025 under the federal WARN Act.
How many jobs is Sutro Biopharma cutting?
54 jobs, across 3 official WARN filings.
When do the Sutro Biopharma layoffs take effect?
The most recent filing lists an effective date of Sep 30, 2025. The WARN Act requires roughly 60 days' advance notice, so the filing date precedes the job losses.
Watching Sutro Biopharma?
We'll email you if there are further filings, expansions, or new locations affected.