Purple Biotech Reports Positive New Preclinical Data Demonstrating Multi-Arm Anti-Tumor Activity Across Two CAPTN-3 Tri-Specific Antibodies at ESMO Immuno-Oncology Congress 2025

Core Insights - The CAPTN-3 platform by Purple Biotech demonstrates significant tumor regression through two tri-specific antibodies, IM1240 and IM1305, targeting different tumor antigens [1][2] - The NKG2A arm is crucial for enhancing the anti-cancer immune activity of IM1240, particularly in PD1-resistant patient-derived explants [1][3] Group 1: CAPTN-3 Platform and Antibodies - The CAPTN-3 platform combines T-cell engagement, NKG2A-mediated immune activation, and tumor-antigen targeting into a single tri-specific molecule, showing potential for a synergistic immune response [2][3] - IM1240 has shown strong anti-tumor activity in PD1-resistant models, indicating its effectiveness even in previously resistant tumors [4][6] - IM1305, targeting TROP2, demonstrates high-affinity binding and potent tumor cell killing across various cancer types, reinforcing the platform's versatility [9] Group 2: Preclinical Data and Findings - New preclinical data presented at the ESMO Immuno-Oncology Congress 2025 highlights the anti-tumor activity of IM1240 in models resistant to PD1 therapy [1][2] - Transcriptomic analysis of approximately 11,000 TCGA samples indicates a strong association between NKG2A expression and tumor expression of 5T4 or TROP2, supporting the inclusion of the NKG2A arm in CAPTN-3 designs [1][6] - IM1305 induced sustained tumor regression in humanized triple-negative breast cancer mouse models at low doses, demonstrating broad application potential [7]