HLX3902 / Fosun Pharma - LARVOL DELTA

A novel anti-CD3×CD28×STEAP1 tri-specific T-cell engager with enhanced and durable antitumor responses in prostate cancer (AACR 2026) - "HLX3902 demonstrated enhanced T cell function and sustained in vitro cytotoxicity compared with bispecific TCEs and their combinations, showing superior T-cell proliferation and enhanced expansion of memory T cells. Furthermore, Anti-CD3×CD28×STEAP1 TCE demonstrated superior and sustained antitumor activity in both humanized PBMC/cell line-derived xenograft and PDX models at a single 0.01 mg/kg dose, with increased T-cell infiltration, activation, and persistent intratumoral CD8+ T cells resulting from CD28 co-stimulation compared to AMG509... We developed a novel tri-specific TCE with optimized CD3 and CD28 signaling, effectively co-engages T cells and STEAP1-expressing tumor cells. It elicits potent, target-dependent T-cell activation and cytotoxicity, The incorporation of CD28 signaling significantly improved T-cell persistence and sustained functional activity against repeated antigen challenges in vitro and in vivo. It was well tolerated in cynomolgus..."

Trispecific • Genito-urinary Cancer • Oncology • Prostate Cancer • Solid Tumor • CD8 • STEAP1