Despite patients undergoing surgery, chemotherapy, and radiation therapy, there is a high rate of recurrence for this type of tumour.
The increased rate of recurrence in glioblastomas can be attributed to the failure of even the most targeted drugs to cross the blood brain barrier in adequate quantities.
With only small amounts of the drug reaching the tumour, it is insufficient to destroy the entire tumour and only manages to damage the tumour. This provides an opportunity for the tumour to develop mechanisms to adapt to the drugs being administered, driving drug resistance.
The aim of researchers has been to explore a combination of drugs that will target the tumour, as well as stop the tumour from developing drug resistance.
The researchers at the Jonsson Comprehensive Cancer Research Centre at UCLA have investigated one such combination of drugs in tumour models.
The combination includes using erlotinib, a FDA approved drug, followed by idasanutlin, an experimental drug.
In the study published in Nature Medicine, the researchers evaluated the combination treatment in mice with glioblastomas.
First, the researchers administered erlotinib, which reduces the tumour’s uptake of sugar. By cutting off the energy supply of the tumour, it prevents the tumour from growing and makes it more susceptible to subsequent treatment.
This vulnerable state of the tumour was exploited by the researchers who administered idasanutlin, which stimulated the death of tumour cells.
The research team, led by Dr Nathanson, noted the success of this combination of drugs as they observed tumour regression in majority of the glioblastomas in the mice they tested.
Although this treatment combination is still in the pre-clinical stages, it could have a significant impact on individuals with glioblastomas, as the researchers are keen to move on to clinical testing.