Aptevo announces addition of preclinical candidate APVO455 to portfolio

Aptevo Therapeutics (APVO) announced the addition of preclinical candidate APVO455 to its growing portfolio of CD3-directed candidates built on the CRIS-7 derived CD3 binding domain-an approach demonstrating compelling potential across both hematologic and solid tumors. With this announcement, Aptevo now has a suite of three CD3-engaging molecules in development. All three share the same CRIS-7 derived binding domain with a low cytokine release profile. In addition, APVO455 and APVO442 contain CD3 binding domains that are optimized for targeting solid tumors. All three molecules are designed to drive tumor-specific immune activation while limiting systemic toxicity. The suite includes: Mipletamig , a CD123 x CD3 bispecific currently in Phase 1b/2 for frontline AML, where 85% of evaluable frontline patients across two trials have achieved remission in combination with standard of care. No cytokine release syndrome has been observed in the first two trial cohorts of the ongoing RAINIER trial. APVO442 , a PSMA x CD3 candidate targeting prostate cancer, currently in preclinical development. And now APVO455 , a Nectin-4 x CD3 bispecific developed to address multiple solid tumor types.