Updated results demonstrate sustained efficacy with a good safety profile

Degree of tumor shrinkage on CT scans correlates with strength of CD8⁺ T cell specific immune response against EO2401 supporting the notion that efficacy is directly driven by EO2401, i.e., validating the OncoMimics approach

Paris, France – October 23^rd, 2023

Enterome, a clinical-stage company developing first-in-class immunomodulatory drugs for solid and liquid malignancies and inflammatory diseases based on its unique Mimicry platform, today announced updated, encouraging results from Phase 1/2 SPENCER trial of EO2401 in combination with nivolumab in adrenocortical carcinoma (ACC) and metastatic pheochromocytoma/paraganglioma (MPP), two forms of adrenal tumors. EO2401 is composed of three non-self, microbiome-derived HLA-A2 restricted peptides, designed to activate memory CD8 T cells targeting tumor-associated antigens (TAAs) upregulated in adrenal tumors.

The data was featured in an oral presentation at the European Society for Medical Oncology (ESMO) Congress 2023. The presentation entitled, “EO2401 (E) peptide immunotherapy + nivolumab (N) in adrenocortical carcinoma (ACC) and metastatic pheochromocytoma/paraganglioma (MPP); EOADR1-19/SPENCER” was delivered by Prof. Eric Baudin, Head of the Endocrine Oncology Unit at Gustave-Roussy, Villejuif, France.

“We are excited to share positive, updated results from the SPENCER trial at this year’s ESMO Congress,” said Pierre Belichard, Chief Executive Officer of Enterome. “EO2401 in combination with nivolumab continues to demonstrate a meaningful anti-tumor activity in patients with adrenal tumors. The combination was well-tolerated and generated durable immune responses.”

Dr. Eric Baudin, Associate Professor and Head of the Endocrine Oncology Unit at Gustave-Roussy, commented: “The results presented at ESMO are very encouraging. The data represents a clinical validation of EO2401 as demonstrated by the correlation between the strength of immune response and degree of tumor shrinkage on CT scans, a direct measure of tumor activity”.

Conclusion as presented at the ESMO conference:

• EO2401 in combination with nivolumab was generally well tolerated in patients with advanced/metastatic adrenal tumors
• Encouraging results in pretreated patients with ACC; median duration of disease control of 9 months, and 3 of 26 patients stopped study treatment at 2 years only due to protocol
• Longer follow-up needed to interpret results in pheochromocytoma/paraganglioma patients
• EO2401 in combination with nivolumab achieved long term stabilizations of “cold tumors” (TMB-low, MSS, PDL1-low adrenal tumors; ACC and MPP)
  • Specific CD8 T cell immune responses could be a biomarker

About SPENCER

SPENCER (EOADR1-19) is a multicenter, open-label, first-in-human, Phase 1/2 study of EO2401 in combination with an immune checkpoint inhibitor (nivolumab) for the treatment of patients with locally advanced or metastatic adrenocortical carcinoma, or malignant pheochromocytoma/paraganglioma. The study aims to assess the safety, tolerability, immunogenicity, and preliminary efficacy of the combination in sites in Europe and the US.

For more information on the Phase 1/2 trial of EO2401 in adrenocortical carcinoma, please visit  ClinicalTrials.gov Identifier: NCT04187404

About EO2401

EO2401 is Enterome’s first-in-class off-the-shelf OncoMimics™ peptide-based immunotherapy. It combines three microbial-derived OncoMimics™ peptides that closely mimic specific cytotoxic T cell (CD8⁺ T cell) epitopes on the Tumor-Associated Antigens IL13Ra2, BIRC5, and FOXM1, combined with the helper peptide (CD4⁺ T cell epitope) Universal Cancer Peptide 2 (UCP2).

About OncoMimics^™

OncoMimics^™ immunotherapies are designed to activate pre-existing effector memory T cells that target bacterial (non-self) peptides, which are strongly cross-reactive against selected Tumor-Associated Antigens (TAAs), or B cell markers expressed on tumoral cells, resulting in a rapid, targeted cytotoxic response against cancer.

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