Sensei Biotherapeutics (SNSE) shares climb after announcing positive new data from ongoing Phase 1/2 clinical trial of SNS-301, an investigational medicine in patients with advanced squamous cell carcinoma of the head and neck (SCCHN), in combination with pembrolizumab.
As of the data cut-off, a safety analysis conducted in 20 evaluable patients showed that SNS-301 in combination with pembrolizumab continues to have a favorable safety profile.
- The combination of SNS-301 and pembrolizumab was well tolerated. Mostly Grade 1-2, mild to moderate, unrelated adverse events (AE) were observed. Four Grade 3 AEs were reported as treatment-related: dehydration, pruritus, rash and EKG QT prolongation.
An analysis of anti-tumor activity was conducted in 12 patients who did not achieve an objective response to prior treatment with PD-1 blockade (Cohort A). No patients were evaluable from Cohort B as of the cut-off date.
- 67% (n=8/12) of patients achieved stable disease (SD) or partial response (PR), including:
- One patient with PD-L1 negative tumor who achieved a tumor reduction of 71% that is still ongoing after 11 months of therapy. Nanostring™ data for this patient show T-cell increase and T-cell activation.
- Seven patients achieved SD, including two patients with long-standing SD (8 and 10 months).
Patient outcomes appear to correlate to post-treatment PD-L1 expression and immune infiltration in tumors.
Analyses of secondary endpoints using ELISA and ELISPOT assays to evaluate SNS-301 specific B and T cell responses in patient samples are ongoing. Sensei expects to report these data as part of the larger dataset planned by the end of 2021. Sensei also plans to add a third cohort by the end of 2021 to evaluate SNS-301 with HPV-specific E6/E7 ImmunoPhage.
