Glioblastoma (GBM) is an aggressive and malignant form of glioma, with a dismal 5% five-year overall survival rate1. The treatment for glioblastoma has largely remained unchanged for over a decade, with the last advance being the addition of a chemotherapeutic agent to a patient’s treatment regimen alongside radiotherapy2. Immunotherapy provides a new therapeutic option to enhance cancer survival rates. One such therapy is Chimeric Antigen Receptor (CAR) T cell therapy, which involves genetically modifying a patient's own T-cells to express a synthetic receptor, designed to specifically bind to a tumour expressed mutation. Once bound, the T-cell kills the malignant cell. This therapy has been incredibly successful in treating haematological cancers3. One challenge for CAR T cell therapy is identifying a tumour specific target, to minimise on target/off tumour side effects. EGFRvIII is a tumour specific mutation of EGFR, caused by the deletion of exons 2-7 from the extracellular domain of EGFR. EGFRvIII mutations occur in a subset of GBM, as well as breast and ovarian cancer4.
We have identified two EGFRvIII-specific short chain variable fragments (scFv) using phage display screening and cloned these into a second generation CAR construct. The recombinant scFv were confirmed to have high and specific affinity to EGFRvIII using Surface plasmon resonance (SPR). We have successfully generated EGFRvIII-specific CART cells and provide data to demonstrate both specificity of the scFvs to the EGFRvIII mutation, and cytotoxic function against EGFRvIII-expressing targets.