Sensei Biotherapeutics : Company Presentation January 2023

Conditionally Active Antibodies for Immuno-oncology

JANUARY 2023 | Nasdaq: SNSE

Disclaimer

This presentation has been prepared by Sensei Biotherapeutics, Inc. (the "Company," "we," "us") and is made for informational purposes only. The information set forth herein does not purport to be complete or to contain all of the information you may desire. Statements contained herein are made as of the date of this presentation unless stated otherwise, and neither the delivery of this presentation at any time, nor any sale of securities, shall under any circumstanc es create an implication that the information contained herein is correct as of any time after such date or that information wil l be updated or revised to reflect information that subsequently becomes available or changes occurring after the date hereof.

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Engineered Selectivity to Extend the Reach of Immuno-oncology Agents

THE CHALLENGE

Systemically delivered I/O drugs often fail in the clinic due to on-target/off-tumor effects (TMDD, CRS)

OUR LEAD PROGRAM

SNS-101 is a pH-sensitive antibody targeting the VISTA receptor with IND expected in or prior to April 2023

OUR STRATEGY

Conditionally active antibodies engineered to enable druggability of promising oncology targets

OUR FINANCIAL POSITION

Ended 3Q 2022: $116.6M* Cash runway into 2H 2025

*Consists of cash, cash equivalents and marketable securities

3

Innovative Pipeline of IO Drugs with Broad Commercial Potential

Program (Target)	Indication	Discovery	IND-enabling	Phase 1 / 2 Clinical
SNS-101* (VISTA)	Solid Tumors
SNS-102	(VSIG4)	Solid Tumors
SNS-103	(ENTPDase1/CD39)	Solid Tumors

*Sensei has entered into a clinical supply agreement with Regeneron supporting the planned evaluation of SNS-101 in combination with Regeneron's anti-PD-1 therapy Libtayo® (cemiplimab) in a Phase 1/2 clinical trial in solid tumors.

4

The Modern-Day Challenge in Immuno-Oncology

The PD-1/PD-L1 market is big and growing fast1

2020

2026

PD-1/PD-L1 monotherapy does not benefit 70% of patients2

Survival

Benefit

20-30%

No Survival Benefit 70%

1. Gerber et al., Biochemical Pharmacology2016	5
2. Market estimates from PD-1 and PDL-1 Inhibitors Market Size in 2021 - MarketWatch, 360 Research