---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-22-300545"
form_type: "8-K"
ticker: "SNSE"
cik: "0001829802"
company_name: "Sensei Biotherapeutics, Inc."
filed_at: "2022-12-08T23:59:59+00:00"
generated_at: "2026-06-21T07:42:03.025103+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Sensei Biotherapeutics reduces workforce by 40%, closes Boston site, extends cash runway to H2 2025

## Summary
- Workforce reduction of ~40% to cut operating expenses; one-time charge of ~$1.0M expected in Q4 2022/Q1 2023.
- Boston research site closed; operations consolidated to Rockville, MD; cash runway extended into H2 2025.
- Robert Pierce terminated as Chief R&D Officer; moves to consulting role as Science Fellow effective Dec 7, 2022.
- Edward van der Horst promoted to Chief Scientific Officer effective Dec 7, 2022; oversees SNS-101 development.
- IND submission for lead antibody SNS-101 (anti-VISTA) anticipated by April 2023; discovery work on VSIG-4 and CD39 continues.

## SEC filing metadata
- accession: 0001193125-22-300545
- form_type: 8-K
- ticker: SNSE
- cik: 0001829802
- company_name: Sensei Biotherapeutics, Inc.
- filed_at: 2022-12-08T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 2.05, 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1829802/000119312522300545/0001193125-22-300545-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1829802/000119312522300545/d431901d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-22-300545
- JSON: https://secwatch.observer/filing/0001193125-22-300545.json
- Plain text: https://secwatch.observer/filing/0001193125-22-300545.txt

## Key facts
- Executive change
  Robert Pierce was terminated as Chief Research and Development Officer at Sensei Biotherapeutics, Inc..
  - Action: terminated
  - Role: Chief Research and Development Officer
  source text: On December 7, 2022, the Company notified Robert Pierce, who had been serving as the Company’s Chief Research and Development Officer, that his employment with the Company would terminate, effective December 7, 2022.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1829802/000119312522300545/0001193125-22-300545-index.htm
- Restructurings & Charges
  Sensei Biotherapeutics, Inc. announced a restructuring with charges of approximately $1.0 million affecting Company (approximately 40% of its workforce).
  - Type: restructuring
  - Charge: approximately $1.0 million
  - Affected area: Company
  - Headcount: approximately 40% of its workforce
  source text: On December 5, 2022, the Board of Directors of Sensei Biotherapeutics, Inc. (the “Company”) approved a plan to reduce the Company’s current workforce by approximately 40% to decrease operating expenses. The Company expects the reduction in force to be substantially completed in the first quarter of 2023. As a result, the Company estimates that it will incur a one-time charge of approximately $1.0 million in connection with one-time employee termination costs, including severance and other benefits.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1829802/000119312522300545/0001193125-22-300545-index.htm

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