It has been found that immune cells, known as T cells, can be engineered to attack a form of brain cancer that is quite often fatal. The brain cancer type under investigation is glioblastoma, a cancer of astrocytes, one of the supportive cell types in the brain. Glioblastoma is a very common form of brain cancer and the tumours are notoriously aggressive, with many patients surviving less than 18 months following diagnosis.
The T cells are engineered to express a specific antigen receptor (CAR) that targets a mutation in a receptor, EGFRvIII, which is found in 30% of glioblastoma patient’s cells. This mutated receptor is associated with a worse prognosis and they respond less effectively to standard treatments. Without delving too far into the molecular biology, the team found that the T cells could proliferate and secrete signalling molecules in response to these tumour cells. The cells controlled tumour growth, caused shrinkage and also increased the efficacy of chemotherapy whilst leaving the normal cells unaffected.
The method of using engineered T cells to treat cancers is not a new one. It was previously shown in a number of trials that T cells were effective in treatment of some blood cancers. The technique for clinical trials would involve removing the patients normal T cells engineering them using a virus vector, and then reintroducing them into the patient where they proliferate. A new trial will involve 12 adults with these EGFRvIII glioblastomas, six of which are relapsed patients and six of which are newly diagnosed cancers and still have greater than one centimetre of tumour tissue left following surgery.
The study was carried out by a team from the Perelman School of Medicine at the University of Pennsylvania and the Novartis Institutes for BioMedical Research, the research was published in Science Translational Medicine.