Target for APN431 is the E3 Ubiquitin ligase Cbl-b, the compounds are cell-permeable cbl-b inhibitory peptides that activate human immune cells and show antitumor effects in tumor model in immunocompetent mice. The approach was originally developed for immunotherapy of fungal infections (Wirnsberger G et al.; Nature Medicine 2016).
The project is being in-licensed from the Institute of Molecular Biotechnology (IMBA, Vienna).