Positive DEP HER2-Lu preclinical data support Phase 1 entry

• Strong tumour uptake and retention with low kidney accumulation
• Statistically significant anti-tumour activity and survival benefit
• FDA feedback supports planned development pathway
• Phase 1 study planned for H2 CY2026

Starpharma Holdings Ltd. announced positive preclinical data for its DEP® HER2-targeted radiotherapy candidate, DEP® HER2-lutetium (DEP® HER2-Lu). The data demonstrated strong tumour uptake and retention, low kidney accumulation, and short blood circulation time in preclinical HER2-positive cancer models. The DEP® dendrimer component improved biodistribution compared to a non-DEP® HER2-targeting construct. DEP® HER2-Lu showed statistically significant anti-tumour activity and survival benefit in preclinical models, comparable to Enhertu®. Phase 1 preparations are well advanced, with first-in-human evaluation planned for H2 CY2026. FDA feedback supports the proposed development pathway. DEP® HER2-Lu was well tolerated in preclinical studies, with no abnormal clinical findings or significant changes in haematology parameters.