– SNS-301 demonstrated prolonged partial response and improvement in immune markers in PD-L1 negative disease patient with 43% tumor reduction

– 30+ week stable disease observed in 2 patients

BOSTON, Mass. & GAITHERSBURG, Md.–(BUSINESS WIRE)–Sensei Biotherapeutics, Inc., a clinical-stage biopharmaceutical company developing next generation immunotherapies for the treatment of cancer and infectious diseases, today reported new data from its ongoing Phase 1/2 clinical trial of SNS‑301, Sensei’s lead program from its ImmunoPhage platform, in patients with Locally Advanced Unresectable or Metastatic/Recurrent Squamous Cell Carcinoma of the Head and Neck (SCCHN). The data were presented in a poster session at the Society for Immunotherapy of Cancer’s (SITC) 35th Anniversary Annual Meeting.

“Early Safety and Efficacy of a Phase 1/2 Multi-Center Trial of SNS-301 Added to Pembrolizumab in Patients with Advanced Squamous Cell Carcinoma of the Head and Neck”

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“These promising new data build upon the initial safety and efficacy data for SNS-301 in patients with ASPH-positive SCCHN and provide additional confidence that SNS-301, when combined with checkpoint inhibition, has the potential to provide long-term benefit as 2nd and later line treatment for patients,” said Marie-Louise Fjällskog, M.D., Ph.D., Chief Medical Officer of Sensei Biotherapeutics. “These results, including a partial response in an advanced SCCHN patient with a PD-L1 negative tumor, as well as translational data demonstrating a shift from an immune desert to an inflamed phenotype, represent a notable achievement for Sensei, further validating our unique phage-based platform approach.”

The multi-center Phase 1/2 clinical trial is designed to assess the safety, efficacy and immunogenicity of SNS-301 in SCCHN patients that did not achieve tumor reductions on anti-PD-1/PD-L1 therapy alone. As of the data cutoff date of October 6, 2020, eleven patients were enrolled in the study and enrollment is ongoing. Key highlights from the poster titled “Early Safety and Efficacy of a Phase 1/2 Multi-Center Trial of SNS-301 Added to Pembrolizumab in Patients with Advanced Squamous Cell Carcinoma of the Head and Neck” are:

  • Disease control in 6 of 9 patients evaluable for efficacy, including:
    • One patient with PD-L1 negative disease achieved a partial response (PR) with a tumor reduction of 43% at week 12 and was confirmed at week 18. Immunohistochemical staining of this patient’s tumor pre- and post-treatment demonstrated clear increases in CD8 density and PD-L1 expression on CD8 T cells and macrophages. This patient also achieved a clear serological response.
    • One patient achieved a stable disease (SD) for more than 4 months following progressive disease (PD) after 10 months of PD-1 blockade treatment prior to study entry.
    • Two patients achieved SD for 36+ weeks.
  • Of the three patients that had PD as their best response, two had PD on single agent PD1 blockade when entering the study.
  • SNS-301 was well tolerated with no dose-limiting toxicities and observed adverse events (AEs) have primarily been either Grade 1 or 2 and mostly unrelated to treatment.
  • Nanostring analysis of tumors from patients with a partial response, stable disease, and progressive disease was generally concordant with clinical effect, including across immune parameters such Th1 markers, IFN-gamma, Granzyme B, and CD8 T cells.

In addition to the new safety and efficacy data presented today, Sensei also presented a trial-in-progress (TIP) poster describing the design of the ongoing Phase 1/2 clinical trial of SNS-301 in combination with pembrolizumab in SCCHN patients.

About SNS-301

SNS-301 is a first-in-class cancer immunotherapy designed to overcome immune tolerance and induce robust and durable antigen-specific humoral and cellular responses. It is a bio-engineered, inactivated bacteriophage virus expressing a fusion protein of native bacteriophage GPD (Glyceraldehyde-3-phosphate dehydrogenase) protein and a selected domain of aspartate β-hydroxylase (ASPH). Expression of ASPH is uniquely upregulated in more than 20 different types of cancer and expression levels in various tumors are generally inversely correlated with disease prognosis. ASPH signaling is related to cancer cell growth, cell motility and invasiveness, occurs through the Notch pathway and is implicated in the epithelial to mesenchymal transition (EMT).

About Sensei Biotherapeutics

Sensei Biotherapeutics is a clinical-stage biopharmaceutical company focused on the discovery, development and delivery of next generation of immunotherapies for the treatment of cancer and infectious diseases. The company has developed a unique phage-based platform, ImmunoPhage™, that enables the rapid generation of immune activating agents that fully engage the immune system. Using its proprietary ImmunoPhage™ platform, Sensei is developing a library of ImmunoPhage targeting multiple tumor associated antigens to treat patients using a personalized yet off the shelf cocktail approach. The platform enables efficient, scalable and cost-effective manufacturing to support all clinical programs. Its most advanced program, SNS-301, a first-in-class ImmunoPhage™ targeting Aspartyl beta Hydroxylase (ASPH) in advanced Squamous Cell Carcinoma of the Head and Neck (SCCHN), is currently enrolling patients in a Phase 1/2 clinical trial. Its earlier stage programs include SNS-401, a ImmunoPhage™ cocktail for the treatment of Merkel Cell Carcinoma and SNS-VISTA, antibody-based therapeutic targeting V-domain Ig suppressor of T cell activation (VISTA). The company brings together scientific leaders in biology, immunology, and oncology along with a highly experienced management team and scientific advisors. For more information, please visit www.senseibio.com.


Kathryn Morris
The Yates Network

Julie Seidel
Stern Investor Relations, Inc.