Purple Biotech Reports Tri-Specific Cancer Antibody Data, Plans FDA Submission 2026

Purple Biotech, a clinical-stage company focused on novel cancer therapies, announced new data supporting its CAPTN-3 tri-specific antibody IM1240, which targets the tumor-associated antigen 5T4 and is advancing toward first-in-human clinical trials with an IND submission planned for 2026. Research led by Dr. Amir Horowitz at Mount Sinai demonstrated that IM1240 induces tumor cell death in patient-derived treatment-resistant head and neck cancer biopsies and shows synergistic immune activation by engaging both NK and T cells. Additionally, Purple Biotech revealed progress on a second CAPTN-3 tri-specific antibody, IM1305, which targets TROP2, a protein broadly expressed in solid tumors and linked to poor prognosis. IM1305 features a masked anti-CD3 arm designed to activate specifically within the tumor microenvironment, reducing off-target effects and allowing higher dosing. Preclinical studies of IM1305 showed sustained tumor regression in triple negative breast cancer models and significant cell death in various cancers at very low doses. Together, these developments highlight Purple Biotech's innovative approach to overcoming tumor immune evasion and drug resistance through its CAPTN-3 platform.