ExpreS2ion Biotech (EXPRS2) Biostock Life Science Summit summary

Technology and Pipeline Overview

• ES2B-C001 is a novel HER2-targeted breast cancer vaccine using a proprietary VLP platform and validated antigen production system, previously proven in phase III for a COVID-19 vaccine.

• The vaccine induces a strong polyclonal antibody response, is highly immunogenic, safe, and compatible with standard of care treatments.

• Preclinical studies show significant tumor inhibition, 100% survival in animal models, and no observed resistance or major toxicities such as cardiac, gastrointestinal, liver toxicity, or thrombocytopenia.

• The technology overcomes monoclonal antibody resistance and breaks immune tolerance to HER2.

• Potential exists to expand indications to other HER2-driven cancers, such as gastric cancer.

Clinical Development and Milestones

• Clinical Trial Application (CTA) was filed in Q3 2024, with phase I trials planned to start in Austria in Q1 2025.

• Interim results from the phase I trial are expected during 2025, with trial completion anticipated in early 2026.

• Phase II trials are planned to establish clinical proof of concept and maximize asset value, with completion targeted for 2026-2029.

• The company recently completed a rights issue, raising SEK 76 million, and has cash reserves and warrant subscriptions supporting near-term milestones.

• Two warrant schemes (TO 10 and TO 11) are active, providing additional funding opportunities.

Competitive Positioning and Partnerships

• The vaccine addresses resistance issues seen with monoclonal antibodies and other current therapies, offering a potential long-term solution with improved safety and scalability.

• Early licensing is being considered, but the focus remains on reaching clinical proof of concept before major deals; out-licensing is planned after Phase II.

• A non-binding agreement is in place with Serum Institute of India regarding malaria vaccine assets, with a definitive agreement seen as significant validation.

• The leadership team and board bring extensive vaccine development and oncology experience, with a balanced gender split and a scientific advisory board of leading oncologists.

• The target market for the breast cancer vaccine is estimated at EUR 27 billion, with high growth expected over the next five years.