ExpreS2ion Biotech (EXPRS2) Investing in Life Science 2025 summary

Disease landscape and unmet need

• Breast cancer affects 2.3 million women annually, with 700,000 deaths, projected to rise to 3 million cases and 1 million deaths by 2040.

• HER2-expressing tumors are present in 80% of cases; up to 50% relapse due to drug tolerance.

• Incidence in women under 50 has increased by nearly 80% since 1990.

Therapeutic innovation and clinical data

• Developed a virus-like particle immunotherapy targeting all four extracellular domains of HER2, unlike current drugs that target only one.

• Preclinical data show strong antibody response and tumor inhibition in resistant breast cancer models.

• In mice, vaccine with adjuvant led to 100% tumor-free survival over their lifespan.

• Initial phase I human data show significant HER2-specific antibody increase in the first patient.

Development timeline and milestones

• Full treatment curve for first patient expected by December; phase I-A safety and dosage data by mid-2026.

• Phase I-B to conclude by end of next year with early efficacy data from 27 patients.

• Phase II Proof of Concept to follow, with potential licensing or early approval if data are strong.

• Targeting product launch in 2032–2033, with licensing to a larger partner after phase II.