EO-2463

Dr. Mobasher held several executive roles in industry, most recently CMO at BeiGene IFLI contributed up to $9 million to Enterome’s private funding round in 2025 Enterome has announced a series of encouraging clinical data for OncoMimics™ drug candidates in solid tumors and B-cell lymphomas Paris, France – 29 JANUARY, 2025 Enterome SA , a clinical-stage company pioneering OncoMimics™, a new class of off-the-shelf, multi-targeted in vivo immune therapies that induce a fast and potent expansion of memory T-cells to fight cancer, has appointed Mehrdad Mobasher, M.D., M.P.H., a hematologist and oncologist and senior biopharmaceutical executive with more than 15 years of leadership experience in global drug development and commercialization, to its Board of Directors. Dr. Mobasher is currently an executive partner at the Institute for Follicular Lymphoma Innovation (IFLI), which is a key investor in Enterome. The company recently announced highly encouraging clinical results with its immune candidate therapies across a range of blood cancers and solid tumors. “IFLI’s highly collaborative support for the development of our OncoMimics™ in vivo immune therapies targeting follicular lymphoma and other forms of B-cell lymphoma has been transformative for Enterome. Dr. Mobasher joining our board further strengthens IFLI’s invaluable support,” said Pierre Belichard, CEO at Enterome. “Enterome has generated promising clinical data in B-cell non-Hodgkin lymphomas, including follicular lymphoma, as well as in selected solid tumors through an entirely new immunotherapy approach. I’m excited to join the Board and work with the leadership team to help translate this innovative science into meaningful outcomes for patients,” said Dr. Mehrdad Mobasher. Dr. Mobasher is a hematologist-oncologist with more than 15 years of leadership experience in drug development. Most recently, he held the position of Chief Medical Officer at BeiGene, leading the hematology portfolio and global launch of zanubrutinib in CLL and follicular lymphoma. Before that, he held roles as Global Head of Oncology Development at Zai Lab, Chief Medical Officer at Corvus Pharmaceuticals, and Group Medical Director at Genentech, where he led the development and launch of several landmark oncology programs including venetoclax and obinutuzumab . In October 2025, Dr. Mobasher was named Executive Partner at IFLI, a global non-profit foundation dedicated to advancing research and treatment for follicular lymphoma. IFLI became an Enterome shareholder when it invested up to $9 million in a $19 million private funding round in June 2025. In December, Enterome presented positive updated Phase 2 interim data from two cohorts of patients with low tumor-burden follicular lymphoma for its lead OncoMimics™ immunotherapy EO2463. The immune therapy candidate also secured FDA Fast Track designation for the watch and wait setting in follicular lymphoma in October. Enterome has also given positive data updates for EO4010 in metastatic colorectal cancer , and for EO2401 in glioblastoma . The Institute for Follicular Lymphoma Innovation (IFLI) is a global, non-profit, private foundation dedicated to accelerating the development of innovative treatment options for patients with follicular lymphoma (FL). IFLI supports cutting-edge research and technology to lead to the development and commercialization of novel therapeutics and/or biomarkers for the treatment of FL, and to understand the biology of FL. The foundation deploys its budget across research funding, project-based partnerships, and venture philanthropic investments to achieve its innovation goals. IFLI promotes collaboration and works to enable data sharing and the exchange of knowledge and expertise among researchers and institutions advancing FL research. Learn more at . Enterome SA ( ) is a privately held clinical-stage biopharmaceutical company developing breakthrough OncoMimics™ immunotherapeutics for cancer. The three most advanced product candidates have shown positive early data in Phase 2 clinical development, supporting the novel OncoMimics™ modality. The company’s pioneering approach to drug discovery is based on the unique and powerful bacterial Mimicry drug discovery platform, which allows it to discover OncoMimics™ with high similarity to tumor associated antigens (TAA) based on the big-data insights from millions of gut bacterial proteins that live in humans. For more information, please contact: ENTEROME INVESTOR & MEDIA RELATIONS Pierre Belichard Chief Executive Officer +33 (0)1 75 77 27 85 communication@enterome.com Cohesion Bureau Chris Maggos / Giovanni Ca’Zorzi +41 (0)79 367 6254 / +33 (0)7 84 67 07 27 enterome@cohesionbureau.com Attachment 20260129 Enterome PR Mobasher (final)

New data show 100% (6/6) objective response rate (ORR) with EO2463 in previously untreated patients with follicular lymphoma needing treatment in combination with rituximab (SIDNEY Cohort 3)Of the 6 patients, 5 had a complete response (CR), 1 partial response (PR)Patients with follicular lymphoma in watch-and-wait setting (SIDNEY Cohort 2) showed a 52.6% ORR with EO2463 monotherapy Paris, France – 9 DECEMBER 2025 (08:30 CET)Enterome, a clinical-stage company pioneering OncoMimics™, a new class of off-the-shelf, multi-targeted in vivo immune therapies that induce a fast and potent expansion of memory T-cells to fight cancer, today presents highly encouraging updated interim data from two cohorts of patients with low tumor-burden follicular lymphoma in the ongoing SIDNEY Phase 2 trial of its lead OncoMimics™ immunotherapy EO2463. The data were presented at the 67th meeting of the American Society for Hematology (ASH) in Orlando, Florida. In Cohort 3, 100% (6/6) ORR was achieved with EO2463 plus rituximab as first-line treatment for previously untreated patients with low tumor-burden follicular lymphoma in need of treatment. In this feasibility assessment among the 6 patients, 5 had a complete response, and one a partial response. The median time to OR was 17 weeks, and to CR 18 weeks. These results marked an improvement over preliminary data submitted in the abstract for ASH. “These new results are encouraging, despite the limited number of patients. The potent and rapid expansion of specific CD8 T-cells induced by EO2463 supports our understanding that OncoMimics™ trigger memory T-cells to generate sustained immune responses. The data suggest that the combination therapy given as a first-line treatment in patients with low-tumor burden follicular lymphoma should be evaluated in further studies,” said Dr Stephen Smith, principal study investigator at the Fred Hutchinson Cancer Center, University of Washington, Seattle, WA, USA, who presented the data. Data from Cohort 2 continue to show that EO2463 monotherapy produces excellent response rates when offered to patients with newly diagnosed follicular lymphoma or marginal zone lymphoma as an alternative to the standard watch-and-wait regime. Previously undisclosed data from 19 evaluable patients with follicular lymphoma showed a 52.6% ORR as of October. The ORR in the total group of 21 patients with follicular lymphoma or marginal zone lymphoma was 47.6% (14.3% CR and 33.3% PR). Current standard of practice is that, while patients often have visibly swollen lymph nodes, no treatment other than watchful waiting is suggested, as long as they do not show troublesome symptoms. Nevertheless, these patients often are understandably anxious about their disease, which progresses in the majority of cases, and then leads to a decreased quality of life. “These new data with EO2463 contribute more compelling evidence and further strengthen our belief in the potential of our OncoMimics™ multi-targeted in vivo immune therapies for blood cancers. I’m looking forward to initiating Phase 3 testing of EO2463 in patients in the watch-and-wait setting in 2026,” said Pierre Belichard, CEO of Enterome. Follicular Lymphoma, one of several types of indolent Non-Hodgkin Lymphoma, is a difficult to treat chronic condition with relapses, characterized by slow progression and few symptoms, and reduced life expectancy. It is usually diagnosed by the appearance of swollen lymph nodes, and the early stages of the disease can be characterized by a lack of troublesome symptoms such as night sweats, fever or weight loss. There is a widespread consensus among leading investigators on the need for a well-tolerated and effective monotherapy to stop or slow progression for patients in the watch-and-wait setting. EO2463 is an innovative, off-the-shelf OncoMimics™ active immunotherapy that combines four synthetic peptides. These non-self, microbial-derived peptides correspond to CD8 HLA-A2 epitopes that exhibit molecular mimicry with the B lymphocyte-specific lineage markers CD20, CD22, CD37, and CD268 (BAFF receptor). It also includes the helper peptide (CD4+ epitope) universal cancer peptide 2 (UCP2). The unique ability of EO2463 to selectively target multiple B cell markers enables the destruction of malignant B lymphocytes. By ensuring broad target coverage across malignant B cells, this novel approach aims to simultaneously improve safety and maximize efficacy, reducing the tumor cells’ capacity to develop immune-resistance mechanisms such as antigen escape. OncoMimics™ consist of bacteria-derived peptide antigens that closely mimic tumor-associated antigens (TAAs) of solid tumors, or cell linage markers as for B cell lymphomas. These antigens induce a fast and potent in vivo expansion of cytotoxic memory CD8+ T cells that were primed by gut bacteria, and are cross-reactive with TAAs/B cell markers. Because the peptides are “non-self”, OncoMimics™ avoid the self-tolerance that limits many cancer immunotherapies to enable rapid, potent, and durable responses to tumors. The synthetically produced peptides are designed in silico, mining Enterome’s proprietary database of 23 million commensal bacteria genes. Each product combines multiple high-affinity peptides to broaden target coverage and mitigate tumor heterogeneity. OncoMimics™ are easy to manufacture, store, distribute and administer as an “off-the-shelf” subcutaneous injection. OncoMimics™ have achieved rapid and potent responses in clinical testing in over 230 patients to date, with a benign safety profile. Enterome SA (www.enterome.com) is a privately held clinical-stage biopharmaceutical company developing OncoMimics™, a breakthrough in in vivo immune therapies for cancer. The three most advanced product candidates have shown positive early data in Phase 2 clinical development in more than 230 patients across solid tumors and hematological malignancies, showing correlation between clinical efficacy and induced immunogenicity and a benign safety profile, activating large quantities of endogenous memory T-cells. For more information, please contact: ENTEROMEINVESTOR & MEDIA RELATIONSPierre BelichardChief Executive Officer +33 (0)1 75 77 27 85communication@enterome.com Cohesion BureauGiovanni Ca’Zorzi / Douwe Miedema +33 (0)7 84 67 07 27 / +352 621 562 764enterome@cohesionbureau.com Attachment 20251209 - Enterome PR ASH posters (final)