Purple Biotech Announces New Preclinical Data From CAPTN-3 Tri-Specific Antibody Platform Presented At ESMO IO Congress 2025

Data demonstrates the significant and sustained tumor regression achieved by the CAPTN-3 platform across two distinct tri-specific antibodies, IM1240 and IM1305, targeting different tumor antigens

Transcriptomic analysis across ~11,000 TCGA samples shows NKG2A expression is strongly associated with tumor expression of 5T4 or TROP2, supporting inclusion of the NKG2A arm in CAPTN-3 designs

NKG2A arm significantly contributes to IM1240 anti-cancer immune activity in PD1-resistant patient-derived explants

REHOVOT, Israel, Dec. 11, 2025 (GLOBE NEWSWIRE) -- Purple Biotech Ltd. ("Purple Biotech" or the "Company") (NASDAQ/TASE: PPBT), a clinical-stage company developing first-in-class therapies that seek to overcome tumor immune evasion and drug resistance, today reported positive new preclinical data from its CAPTN-3 tri-specific antibody platform presented at the ESMO Immuno-Oncology (ESMO IO) Congress 2025. The data presented was generated in collaboration with the laboratory of Dr. Amir Horowitz of the Tisch Cancer Institute at the Icahn School of Medicine at Mount Sinai.

These new preclinical data successfully demonstrates that two CAPTN-3 tri-specific antibodies, IM1240 (capped-CD3×5T4×NKG2A) and IM1305 (capped-CD3×TROP2×NKG2A), each achieve strong anti-tumor activity across different tumor antigens. IM1240 has also shown anti-tumor activity in models resistant to prior PD1 therapy. These results indicate that the CAPTN-3 architecture can generate potent multi-arm activity beyond a single target, supporting the platform's potential applicability across a range of solid tumors. The CAPTN-3 platform is designed to unite three functional mechanisms—T-cell engagement and activation, enhanced by NKG2A-mediated innate and adaptive immune activation, and tumor-antigen targeting—into a single tri-specific molecule intended to coordinate a synergistic immune response.