Enterome presents further efficacy data on its new generation therapeutic cancer vaccine EO2401 at ESMO Congress, demonstrating ability of OncoMimics™ antigens to generate positive clinical outcome

• EO2401 is a first-in-class OncoMimics™ therapeutic cancer vaccine able to significantly expand existing effector memory CD8+ T cells directed at OncoMimics™ peptides corresponding to tumor-associated driver antigens
• Follow-up data from Phase 1/2 clinical trials of EO2401 combined with nivolumab +/- bevacizumab in recurrent glioblastoma (ROSALIE study) and adrenocortical tumors (SPENCER study) demonstrate early and durable immune responses correlating to clinical outcomes
• Findings from trials will support selection of treatment regimen and patient populations for next clinical studies
• Data presented to date provide strong proof-of-concept for Enterome’s unique Mimicry platform as a basis for generating a pipeline of OncoMimics™-based off-the-shelf immunotherapies targeting a broad range of cancers

Paris, France – September 12, 2022

Enterome, a clinical stage biopharmaceutical company developing first-in-class immunomodulatory drugs based on its bacterial Mimicry drug discovery platform, today announces new data from its two Phase 1/2 clinical trials of EO2401 in combination with nivolumab (Opdivo®) +/- bevacizumab (Avastin®), in patients with first progression/recurrence of glioblastoma (ROSALIE trial), and in combination with nivolumab in patients with non-resectable adrenocortical carcinomas (ACC) and metastatic pheochromocytoma/paraganglioma (MPP) (SPENCER trial). The data were presented in a poster (ROSALIE) and an oral presentation (SPENCER) at the European Society for Medical Oncology (ESMO) Congress 2022, on September 10 and 12, respectively, in Paris (France). The poster and presentation can be found here.

EO2401 is Enterome’s first-in-class off-the-shelf OncoMimics™ cancer immunotherapy. It combines three OncoMimics™ peptides that closely mimic IL13Ra2, BIRC5 and FOXM1, all of which are known driver antigens present on aggressive solid tumors. In addition, EO2401 contains a CD4 helper peptide UCP2. Enterome selected these OncoMimics™ peptides using its Mimicry platform, which applies best-in-class biocomputational tools and bioassays to identify novel therapeutics from its proprietary database of 20+ million bioactive gut microbiome peptides and proteins.

Dr. Jan Fagerberg, Chief Medical Officer of Enterome said, “We are excited that EO2401 therapy continues to show promising and sustained efficacy with a good safety profile. These data from the ROSALIE and SPENCER trials are providing important insights that will enable us to select appropriate treatment regimens and patient populations for the next clinical studies with EO2401 in solid tumor indications.”

Pierre Belichard, CEO of Enterome added, “The data presented at ESMO reinforces the positive findings that we communicated at ASCO in June and confirm the power of Enterome’s Mimicry platform to generate novel and highly promising cancer vaccine candidates. These promising data provide a compelling proof-of-concept for our unique Mimicry approach and give us confidence in our ability to generate an extensive pipeline of OncoMimics™-based immunotherapies targeting unmet needs across a wide range of solid and hematologic cancers. Alongside EO2401, we are pursuing recruitment for EO2463 in B cell malignancies and plan to promptly start treating the first patient with ctDNA-defined, minimal residual disease in colorectal cancer with EO2040. We are also actively preparing the next OncoMimics™ candidate EO4010, developed for the treatment of colorectal cancer, to enter the clinic.”

Highlights from the EO2401/ ROSALIE poster presentation at ESMO 2022:

• Follow-up data confirm that EO2401 in combination with nivolumab +/- bevacizumab is well tolerated with a safety profile consistent with the safety profiles of nivolumab and bevacizumab.
• EO2401 in combination with nivolumab generated strong systemic immune responses through activation of specific effector memory CD8+ T cells, correlating with efficacy.
• Addition of bevacizumab to EO2401 and nivolumab supported longer treatment durations, and an increase of objective response rate (ORR – 54.5% vs. 10.3%), disease control rate (DCR – 81.8% vs. 34.5%), and progression-free survival (PFS – 5.5 months vs 1.8 months), with 3 out of the first 11 patients showing complete remission.
• Additional patients are to be treated with EO2401/nivolumab/ bevacizumab combination to support final regimen selection for further studies.

Highlights from the EO2401/ SPENCER oral presentation at ESMO 2022:

• EO2401 in combination with nivolumab is well tolerated in patients with ACC and MPP with a safety profile consistent with the safety profiles of nivolumab monotherapy.
• Clinical efficacy was observed that correlates with the strength of generated immune responses.
• Best efficacy observed in a post-hoc defined subgroup of patients with ACC, including

• Prolonged duration partial responses (ORR 29%)
• 12-month survival rate of 78.6%, highest achieved in any relevant study in this indication

• A randomized study to evaluate EO2401 in combination with nivolumab versus EO2401 monotherapy versus nivolumab monotherapy in this defined ACC population is ongoing.