PET-imaging of Two Vartumabs in Patients With Solid Tumors

VARTUTRACE aims to investigate the biodistribution and pharmacology in patients with solid tumors of two antibody fragments specific for oncofetal CS. VAR2 Pharmaceuticals has identified and characterized oncofetal CS as a group of tumor-specific carbohydrate motifs that appear in placental tissue during fetal development and in most cancers while remaining largely absent from healthy tissue. VAR2 Pharmaceuticals recently developed a panel of antibodies specific for oncofetal CS and characterized their tumor specificity, therapeutic, and safety in pre-clinical models under various formats. VARTUTRACE is a Phase 0 microdosing study of a single administration of \<30 nmol of one of the two most promising antibody fragments identified by VAR2 Pharmaceuticals - C9 and F8. Both antibody fragments will be used as short chain variable fragments (scFvs) labelled with the radioisotope Zirconium-89 (89Zr) and are therefore respectively named 89Zr-C9scFv or 89Zr-F8scFv. As it remains unclear from the pre-clinical in vitro and in vivo data which of the two will have the most optimal tumor targeting properties in patients with solid tumors, both scFvs will be evaluated. The biodistribution, pharmacokinetics, pharmacodynamics, and clearance of two of these antibody fragments is planned to be studied in up to 32 patients with various cancers (i.e. a basket-trial).