Sensei Biotherapeutics Announces Initiation of Combination Arm for Phase 1/2 Clinical Study of SNS-101 with Regeneron’s Libtayo®

– Eleven patients enrolled overall in trial to date, with enrollment progressing faster than anticipated –

– Monotherapy arm has advanced to a fourth cohort, with initial monotherapy PK and safety data expected in the fourth quarter of 2023 and topline monotherapy data expected in 2024 –

– New guidance for initial combination PK and safety data expected in the first quarter of 2024, with preliminary anti-tumor activity data expected in 2024 –

BOSTON, Sept. 27, 2023 (GLOBE NEWSWIRE) — Sensei Biotherapeutics, Inc. (Nasdaq: SNSE), a clinical stage immuno-oncology company focused on the discovery and development of next-generation therapeutics for cancer patients, today announced that the first patient has been dosed in the combination therapy arm of the Phase 1/2 clinical trial for SNS-101, a conditionally active, human monoclonal antibody targeting the immune checkpoint VISTA (V-domain Ig suppressor of T cell activation). This initial cohort of patients will receive a dose of 3 mg/kg of SNS-101 and a flat dose of Regeneron’s PD-1 inhibitor Libtayo^® (cemiplimab) at 350 mg. Additionally, the Company announced that the fourth cohort of the monotherapy arm at a dose of 10 mg/kg has been fully enrolled.

The multi-center Phase 1/2 clinical trial is a dose escalation study to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and efficacy of SNS-101 as both a monotherapy and in combination with Libtayo^® in patients with advanced solid tumors. To date 10 patients have been treated in the monotherapy arm, consisting of four cohorts receiving SNS-101 treatment at 0.3, 1, 3, or 10 mg/kg. Sensei expects to report initial pharmacokinetic and safety monotherapy data in the fourth quarter of 2023, and topline monotherapy data in 2024.

“We are pleased with the rapid enrollment of our clinical trial and are excited to evaluate SNS-101 as a combination therapy earlier than anticipated,” said John Celebi, President and Chief Executive Officer of Sensei Biotherapeutics. “Sensei is now treating patients at a dose significantly higher than any VISTA antibody for which clinical data have been reported, while dosing less frequently at a rate of once every three weeks. We believe these important differentiators underscore the vast potential of SNS-101 to treat patients with solid tumors.”

As a result of faster enrollment than anticipated, Sensei now expects to report initial combination pharmacokinetic and safety data in Q1 2024 with preliminary anti-tumor activity data in 2024.

About Sensei Biotherapeutics:
Sensei Biotherapeutics (Nasdaq: SNSE) is a clinical stage immuno-oncology company focused on the discovery and development of next-generation therapeutics for cancer patients. Through its TMAb™ (Tumor Microenvironment Activated biologics) platform, Sensei develops conditionally active therapeutics designed to disable immunosuppressive signals or activate immunostimulatory signals selectively in the tumor microenvironment to unleash T cells against tumors. Sensei’s lead investigational candidate is SNS-101, a conditionally active antibody designed to block the V-domain Ig suppressor of T cell activation (VISTA) checkpoint selectively within the low pH tumor microenvironment, where VISTA acts as a suppressor of T cells by binding the receptor PSGL-1. The company is also developing SNS-102, a conditional binding monoclonal antibody targeting V-Set and Immunoglobulin Domain Containing 4 (VSIG-4), as well as SNS-103, also a conditionally active monoclonal antibody targeting ecto-nucleoside triphosphate diphosphohydrolase-1 (ENTPDase1), also known as CD39.  For more information, please visit www.senseibio.com, and follow the company on Twitter @SenseiBio and LinkedIn. 

Cautionary Note Regarding Forward-Looking Statements
Any statements contained in this press release that do not describe historical facts may constitute forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements may be identified by words and phrases such as “believe”, “designed to,” “expect”, “may”, “plan”, “potential”, “will”, and similar expressions, and are based on Sensei’s current beliefs and expectations. These forward-looking statements include expectations regarding the development and potential therapeutic benefits of Sensei’s product candidates, as well as the timing of Sensei’s Phase 1/2 clinical trial of SNS-101, including reporting of data therefrom. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements. Risks and uncertainties that may cause actual results to differ materially include uncertainties inherent in the development of therapeutic product candidates, such as the risk that any one or more of Sensei’s product candidates will not be successfully developed or commercialized; the risk of delay or cessation of any planned clinical trials of Sensei’s product candidates; the risk that prior results, such as signals of safety, activity or durability of effect, observed from preclinical trials, will not be replicated or will not continue in ongoing or future studies or clinical trials involving Sensei’s product candidates; the risk that Sensei’s product candidates or procedures in connection with the administration thereof will not have the safety or efficacy profile that we anticipate; risks associated with Sensei’s dependence on third-party suppliers and manufacturers, including sole source suppliers, over which we may not always have full control; risks regarding the accuracy of our estimates of expenses, capital requirements and needs for additional financing; and other risks and uncertainties that are described in Sensei’s Quarterly Report on Form 10-Q filed with the U.S. Securities and Exchange Commission (SEC) on or about August 3, 2023 and Sensei’s other Periodic Reports filed with the SEC. Any forward-looking statements speak only as of the date of this press release and are based on information available to Sensei as of the date of this release, and Sensei assumes no obligation to, and does not intend to, update any forward-looking statements, whether as a result of new information, future events or otherwise.

Investor Contact:
Michael Biega
Senior Director, Investor Relations
Sensei Biotherapeutics
mbiega@senseibio.com

Media Contact:
Chris Railey
Ten Bridge Communications
chris@tenbridgecommunications.com