Aptevo Therapeutics highlights APVO442 preclinical candidate for prostate cancer

Aptevo Therapeutics (APVO) reinforced the strategic importance of its preclinical asset APVO442-an investigational CD3-engaging bispecific antibody designed to treat prostate cancer. APVO442 is built on Aptevo’s next-generation ADAPTIR-FLEX platform and is engineered to selectively activate T cells within the PSMA-expressing tumor microenvironment, offering potential for precision targeting and reduced systemic toxicity. APVO442 is built on the same CRIS-7-derived anti-CD3 binding domain as clinical candidate mipletamig but is specifically engineered for solid tumors, with lower binding affinity and a monovalent format that reduce the risk of immune activation outside the tumor. This design helps ensure that T cells are activated only within the tumor microenvironment, improving safety while maintaining anti-tumor potency. Preclinical data show that APVO442 effectively localizes to PSMA-expressing prostate tumors, triggering a targeted immune response while potentially sparing healthy tissue. The same solid tumor-optimized architecture has also been applied to newly added pipeline candidate APVO455. “With mipletamig performing as designed in the clinic and the addition to the pipeline of APVO455 for multiple solid tumors, we’re confident in the strength of our CD3-based bispecific approach,” said Marvin White, President and CEO of Aptevo. “APVO442 is engineered for the same balance-potent immune activation precisely where it’s needed – in the tumor. It represents yet another high-conviction opportunity to expand into solid tumors, a market where the need is large and growing.”