Aptevo Unveils APVO442 Precision CD3 Bispecific For Prostate Cancer, Advancing Solid Tumor Strategy With CRIS-7 Platform

Builds on the targeted immune activation model validated by mipletamig in AML, adapted for prostate cancer.

Engineered for precision T-cell activation in prostate cancer; part of Aptevo's growing CRIS-7-derived CD3 portfolio targeting both hematologic and solid tumors

SEATTLE, WA / ACCESS Newswire / August 13, 2025 / Aptevo Therapeutics Inc. (NASDAQ:APVO), a clinical-stage biotechnology company focused on developing novel immune-oncology therapeutics based on its proprietary ADAPTIR® and ADAPTIR-FLEX® platform technologies, today 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.