ExpreS2ion submits Clinical Trial Application (CTA) to conduct Phase I study of ES2B-C001, an innovative therapeutic breast cancer vaccine

Hørsholm, Denmark, 06 August 2024 – ExpreS2ion Biotech Holding AB’s affiliate ExpreS2ion Biotechnologies ApS (“ExpreS2ion"), a clinical-stage biotechnology company with a focused portfolio of vaccine candidates targeting infectious diseases and cancer, is proud to announce the submission of ExpreS2ion’s first CTA, to the Austrian Agency for Health and Food Safety (BASG/AGES) for its novel therapeutic candidate, ES2B-C001 against breast cancer. This submission marks an important milestone in the company’s objective to address significant unmet medical needs in oncology.

ES2B-C001 is a first-in-class therapeutic HER2-VLP based breast cancer vaccine designed to generate a strong and durable polyclonal immune response by presenting the entire extracellular domain of human HER2 protein on the surface of virus like particles (HER2-VLP). The submission follows a series of successful preclinical safety and efficacy studies in animal models for breast cancer vaccine. In vitro data obtained with sera from vaccinated animals demonstrated ES2B-C001's potential to overcome resistance to the current immunotherapies used as standard of care inhibiting tumour cell growth, which could in-turn extend and improve patients’ quality of life.

Dr. Farshad Guirakhoo, Chief Science Officer, comments
“This CTA submission for our ES2B-C001 vaccine brings us one step closer to providing a new therapeutic option for patients suffering from HER2+ breast cancer. We are highly encouraged by the preclinical data showing significant tumour growth inhibition in vivo resulting in 100% survival of treated animals when used as a prophylactic and therapeutic vaccine as well as in vitro against monoclonal antibody resistant-human breast cancer cell lines.”

Bent U. Frandsen, Chief Executive Officer, comments
“With the dedication and expertise of our team, we have achieved a pivotal milestone in ExpreS2ion’s journey – our most significant milestone since we decided to focus on our proprietary pipeline. Our submission of the CTA showcases the strength of our innovative technology platform. We remain committed to advancing the science of oncology therapeutics and infectious disease prophylactics, bringing transformative treatments to patients in need. We anticipate initiating the clinical trial in the first quarter of 2025, pending the expected CTA approval by the authorities.”

The planned Phase I clinical trial will evaluate the safety, tolerability, maximum tolerated dose, immunogenicity, and preliminary efficacy of ES2B-C001, alone or in combination with the adjuvant Montanide, in women suffering from HER2 expressing breast cancer. The trial will be conducted at Medical University of Vienna, in Austria.

ExpreS2ion has a strong track record of innovation. Several achievements lead up to this submission:

• ES2B-C001 platform technologies, ExpreS2™ and VLPs, are validated in Phase III clinical trials
• Completion of proof-of-concept studies and safety studies in two mammalian species
• Manufacture and release of drug product
• Selection of phase I clinical trial site (Medical University of Vienna) and supporting CROs
• Scientific advice meeting with BASG/AGES in Austria
• Finalization of phase I clinical trial protocol

About ES2B-C001 (HER2-VLP)
ES2B-C001 represents a novel development in the field of breast cancer therapeutics, specifically targeting human epidermal growth factor receptor 2 (HER2) positive breast cancers. This innovative vaccine is based on proven clinical Phase III-validated technology platforms, leveraging ExpreS2ion's production platform, ExpreS2, and AdaptVac's VLP technology. Extensive preclinical data underscore the safety and efficacy of ES2B-C001 across multiple animal models for breast cancer, as documented in the work of Ruzzi et al. (2022). HER2-positive breast cancer, marked by the overexpression of the human HER2 protein, represents a significant subset of breast cancer cases, impacting a notable proportion of patients. ES2B-C001 harnesses the patient's immune system to stimulate the production of polyclonal antibodies tailored to combat HER2-positive breast cancers. This approach not only adds a complementary dimension to existing therapeutic strategies but also holds promise in addressing the complexities of this challenging oncological domain.

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