---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-24-146093"
form_type: "8-K"
ticker: "SNSE"
cik: "0001829802"
company_name: "Sensei Biotherapeutics, Inc."
filed_at: "2024-05-23T23:59:59+00:00"
generated_at: "2026-06-01T09:20:06.613941+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Sensei Biotherapeutics reports Phase 1 data for SNS-101: 59% tumor reduction in MSS endometrial cancer, well tolerated

## Summary
- Confirmed partial response (59% decrease) in an MSS endometrial cancer patient on SNS-101 plus cemiplimab; remains on study at 30+ weeks.
- No dose-limiting toxicities; most AEs grade 1-2; mild cytokine release syndrome at highest dose manageable.
- PK profile shows linear elimination and dose-proportional exposure, supporting once-every-3-week dosing.
- Tumor regression observed in MSS CRC (27%), pembrolizumab-resistant RCC (18%), and HPV+ head & neck cancer (17%).
- Company expects initial dose expansion data and end-of-Phase 1 FDA meeting by end of 2024.

## SEC filing metadata
- accession: 0001193125-24-146093
- form_type: 8-K
- ticker: SNSE
- cik: 0001829802
- company_name: Sensei Biotherapeutics, Inc.
- filed_at: 2024-05-23T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1829802/000119312524146093/0001193125-24-146093-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1829802/000119312524146093/d830013d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-24-146093
- JSON: https://secwatch.observer/filing/0001193125-24-146093.json
- Plain text: https://secwatch.observer/filing/0001193125-24-146093.txt

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