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

Core Insights - Sensei Biotherapeutics reported promising clinical data for SNS-101, a monoclonal antibody targeting the immune checkpoint VISTA, showing initial signs of clinical activity in advanced solid tumors [1][10] Clinical Trial Overview - The Phase 1/2 trial of SNS-101 includes a dose escalation portion to evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy, both as a monotherapy and in combination with Regeneron's PD-1 inhibitor Libtayo® [3][4] - A total of 34 patients participated, with 16 in the monotherapy arm and 18 in the combination arm, where 85% had tumor types typically unresponsive to PD-1 monotherapy [4] Clinical Activity and Efficacy - Preliminary data indicated promising clinical activity across multiple tumor types, including microsatellite stable colorectal and endometrial tumors, which usually show low response rates to existing immunotherapies [2][4][10] - Specific cases included a 59% decrease in tumor size for an endometrial cancer patient and 27% regression for a colorectal cancer patient, both receiving SNS-101 in combination with cemiplimab [8] Safety and Tolerability - SNS-101 was well tolerated, with no dose-limiting toxicities observed; most adverse events were Grade 1 or 2 [6][10] - Two patients experienced mild Grade 1 cytokine release syndrome, indicating manageable side effects [6][9] Pharmacokinetics - SNS-101 demonstrated a potentially best-in-class pharmacokinetic profile with linear elimination kinetics and dose-proportional increases in exposure, supporting the once every three weeks dosing regimen [5][10] Future Developments - The company is advancing to the dose expansion portion of the trial and expects to report initial data by the end of 2024, along with an end-of-Phase 1 meeting with the FDA [11] - Data will be presented at the 2024 ASCO Annual Meeting on June 1, 2024 [12]