Purple Biotech shares surge 12.74% premarket on positive preclinical data from CAPTN-3 platform showing tumor regression.

Purple Biotech surged 12.74% in premarket trading following the release of positive preclinical data from its CAPTN-3 tri-specific antibody platform. The company demonstrated significant tumor regression in PD1-resistant models using lead candidate IM1240 and validated the platform’s versatility with new TROP2-targeting candidate IM1305. The data, presented at the ESMO IO Congress, highlighted the CAPTN-3 platform’s ability to activate both innate and adaptive immune responses, including efficacy in patient-derived explants resistant to existing therapies. Collaboration with Dr. Amir Horowitz’s lab at Mount Sinai added credibility to the findings, while transcriptomic analysis reinforced the NKG2A arm’s role in enhancing anti-tumor activity. The results position CAPTN-3 as a scalable solution for solid tumors, aligning with the company’s 2026 development milestones and advancing the platform toward IND-enabling studies.