Aptevo Debuts First Trispecific Antibody Candidate, APVO451, with Preclinical Data Demonstrating Immune Activation in Hard-to-Treat Solid Tumors

Core Insights - Aptevo Therapeutics has presented preclinical data for its trispecific antibody candidate, APVO451, at the Society for Immunotherapy of Cancer Annual Meeting, highlighting its potential in treating hard-to-treat solid tumors [1][2]. Company Update - APVO451 is designed to address the challenge of immune suppression in solid tumors, such as urothelial, breast, and pancreatic cancers, by utilizing a proprietary CRIS-7-derived CD3 binding domain [2][3]. - The molecule aims to activate the intratumoral immune system, enhancing the ability to target and kill tumor cells effectively [3]. Key Findings from the Presentation - APVO451 demonstrated local activation of T-cells and antigen-presenting cells (APCs) only when bound to the target protein, nectin-4, indicating a favorable safety profile [4]. - The candidate showed dual immune re-activation by stimulating T-cell effector functions and restoring APC function, addressing a common failure point in solid tumor treatments [4]. - In tumor models simulating suppression, APVO451 was more effective in eliminating nectin-4-positive tumor cells compared to standard CD3 T-cell engagers, suggesting its potential to overcome suppressive tumor environments [4]. Next Steps - Aptevo is advancing APVO451 through ongoing preclinical studies to support IND-enabling work and future clinical development targeting nectin-4-expressing solid tumors [5]. About APVO451 - APVO451 is a trispecific ADAPTIR-FLEX therapeutic candidate designed to engage CD3 and CD40, aiming to restore immune engagement in suppressive solid tumors while minimizing off-tumor activation [6]. About Aptevo Therapeutics - Aptevo Therapeutics is a clinical-stage biotechnology company focused on developing novel bispecific and trispecific immunotherapies for cancer treatment, with two clinical candidates currently in trials [7].