Sensei Biotherapeutics Presents Promising Clinical Data from Phase 1 Dose Escalation Study of SNS-101

- Once every 3-week dosing of SNS-101 demonstrates initial signs of promising clinical activity - 

- Pharmacokinetic and safety profile validate conditionally active approach - 

- Investor webcast to be held on Monday, June 3 at 8:00 a.m. ET -

BOSTON, May 23, 2024 (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 reported encouraging clinical data from the dose escalation portion of its Phase 1/2 trial of SNS-101, a conditionally active, human monoclonal antibody targeting the immune checkpoint VISTA (V-domain Ig suppressor of T cell activation).

“I am pleased that SNS-101 has been well-tolerated in the study, reaching its highest planned dose level with no dose limiting toxicities and demonstrating its potential to successfully overcome the prior challenges of VISTA-targeted programs,” said Dr. Shiraj Sen, Medical Oncologist and Director of Clinical Research at NEXT Oncology, Dallas, and a principal investigator for the SNS-101 study. “The data show encouraging signs of clinical activity in a heterogeneous population of patients with advanced solid tumors, where you typically wouldn’t expect to see clinical responses, especially in microsatellite stable colorectal and endometrial tumors. There is a continued unmet need for patient populations that have become resistant or don’t respond to current immunotherapy treatment options. I look forward to continuing to evaluate its progress.”

Dose escalation portion of the Phase 1/2 clinical trial

The dose escalation portion of the Phase 1/2 clinical trial is designed to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of SNS-101. This study assesses SNS-101 both as monotherapy and in combination with Regeneron’s PD-1 inhibitor Libtayo (cemiplimab, 350 mg), in patients with advanced solid tumors with primary (unfavorable candidates for immunotherapy) or acquired PD-1 therapy resistance (progressed on prior anti-PD-1 therapy).  

A total of 34 patients received SNS-101 once every 3 weeks, with 16 patients in the monotherapy arm and 18 patients in the combination arm. The majority of patients (85%) had a tumor type that is typically unresponsive to PD-1 monotherapy (“cold” tumors).

As of the April 30, 2024 data cutoff, SNS-101 demonstrated preliminary evidence of promising clinical activity in multiple tumor types, including:

• One microsatellite stable (MSS) endometrial cancer patient that received SNS-101 plus cemiplimab had a confirmed partial response (59% decrease) and remains on study at 30+ weeks. MSS endometrial cancer has been previously shown to have a low response rate to monotherapy immunotherapy treatments.
• One MSS colorectal cancer (CRC) patient that received SNS-101 plus cemiplimab remained on study for 18 weeks and had tumor regression of 27%. MSS CRC has been previously shown to be unresponsive to PD-1 treatments.
• One pembrolizumab-resistant renal cell carcinoma patient that received SNS-101 plus cemiplimab remained on study for 12 weeks and had tumor regression of 18%.
• One pembrolizumab-resistant human papillomavirus (HPV)+ head and neck cancer patient that received SNS-101 as monotherapy remained on study for 12 weeks and had tumor regression of 17%.

These clinical data are consistent with preclinical studies suggesting therapeutically relevant clinical doses of SNS-101 at 3mg/kg or higher. Additionally, preliminary flow-based pharmacodynamic analysis showed dose-dependent changes in specific T-cell populations suggesting SNS-101 may be having a pharmacological effect on T-cell subsets.