UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number: 001-39980 Sensei Biotherapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 83-1863385 (State or other jurisd ...

Exhibit 99.1 Sensei Biotherapeutics Reports Full Year 2023 Financial Results and Recent Business Highlights - Updated dose escalation data from SNS-101 clinical study supports favorable and potentially best-in-class safety and PK profile both as monotherapy and in combination with PD-1 blockade - - Topline efficacy and biomarker data for both monotherapy and combination arms of dose escalation study now expected in Q2 2024, ahead of previous guidance - - Strong balance sheet with cash runway into fourth qua ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number: 001-39980 Sensei Biotherapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 83-1863385 (State or oth ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number: 001-39980 Sensei Biotherapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 83-1863385 (State or other ju ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number: 001-39980 Sensei Biotherapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 83-1863385 (State or other j ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number: 001-39980 Sensei Biotherapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 83-1863385 (State or other jurisd ...

Conditionally Active Antibodies for Immuno-oncology FEBRUARY 2023 | Nasdaq: SNSE Disclaimer This presentation has been prepared by Sensei Biotherapeutics, Inc. (the “Company,” "we," "us") and is made for informati ...