Sensei Biotherapeutics (SNSE) Jefferies 2024 Global Healthcare Conference summary

Key program highlights

• Lead asset SNS-101 is a conditionally active, pH-sensitive antibody targeting VISTA, designed to activate only in the tumor microenvironment, reducing toxicity and improving pharmacokinetics.

• Phase I-B study shows SNS-101 is well-tolerated, with no dose-limiting toxicities and only mild cytokine release syndrome (CRS) at high doses, overcoming issues seen with prior VISTA antibodies.

• Early clinical signals include stable disease and tumor regression in patients with cold tumors, such as microsatellite stable colorectal and endometrial cancers, which are typically unresponsive to PD-1 therapies.

• Dose-dependent changes in T cell populations suggest immune activation, with increased tumor-homing and cytotoxic T cells observed.

• Cash runway extends into Q4 2025, supporting ongoing dose expansion and phase II planning.

Clinical data and safety

• 34 patients enrolled in phase I, with 85% having cold tumors; no severe CRS or dose-limiting toxicities observed.

• SNS-101 demonstrated dose-proportional exposure and is suitable for once every 3-week dosing, with no immunogenicity detected.

• Combination with cemiplimab (PD-1 inhibitor) showed no adverse PK interactions and was well-tolerated.

• Notable clinical responses include a 59% tumor shrinkage in endometrial cancer and 27% in colon cancer, both microsatellite stable.

• Expansion cohort data expected by end of 2024, with further updates planned.

Strategic outlook and rationale

• Dose expansion phase underway, targeting 50-70 patients across monotherapy and combination arms in multiple tumor types, including both hot and cold tumors.

• Rationale for cold tumor focus is VISTA's expression on myeloid-derived suppressor cells, which may mediate resistance to PD-1 therapies.

• Plans to explore broader combinations, leveraging favorable safety profile; preclinical collaborations ongoing.

• Initial data from dose expansion expected Q4 2024, with cash runway supporting operations through Q4 2025.