COMPANY DOSSIER
Arsenal Biosciences Layoffs
Yes. Arsenal Biosciences filed a WARN notice to cut 100 jobs in South San Francisco, California, with the layoffs effective Nov 14, 2025. It was filed Sep 16, 2025 under the federal WARN Act.
100 roles affected across 1 filing.
Canary status: SingingEVIDENCE-BASED · NOT A PREDICTION
No WARN filing or SEC event in the recent window — quiet on the wire right now.
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 Arsenal Biosciences's solvency or creditworthiness. Not a credit rating and not financial advice. See our sources and method.
Every filing
South San Francisco, California
Filed Sep 16, 2025 (10mo ago) · Effective Nov 14, 2025 · official filing →
100
LayoffQuestions
Is Arsenal Biosciences laying off employees?
Yes. Arsenal Biosciences filed a WARN notice to cut 100 jobs in South San Francisco, California, with the layoffs effective Nov 14, 2025. It was filed Sep 16, 2025 under the federal WARN Act.
How many jobs is Arsenal Biosciences cutting?
100 jobs, across 1 official WARN filing.
When do the Arsenal Biosciences layoffs take effect?
The filing lists an effective date of Nov 14, 2025. The WARN Act requires roughly 60 days' advance notice, so the filing date precedes the job losses.
Watching Arsenal Biosciences?
We'll email you if there are further filings, expansions, or new locations affected.