Groundbreaking success shown in target drug combination for aggressive brain tumours
pharmafile | November 25, 2021 | News story | Business Services |
A combination of two targeted cancer drugs have shown unprecedented activity in patients with highly malignant brain tumours carrying a rare genetic mutation. According to a trial report by investigators for Dana-Farber Cancer Institute, dabrafenib and trametinib yielded an encouraging rate of durable responses in high-grade and low-grade brain tumours carrying the rare BRAF v600E mutation.
Both drugs target proteins in the MAPK pathway, a signaling chain of proteins acting as a switch for cell growth which can cause uncontrolled growth. The treatment shrank tumours by 50% or more in one third of 45 patients with hard-to-treat gliomas, including glioblastomas, the most aggressive brain tumour.
Patrick Wen, MD, first author of the report in The Lancet Oncology and director of the Center for Neuro-Oncology at Dana-Farber, shared: “This is the first time that any targeted drug has been shown to work in glioblastoma in a clinical trial.” The results are particularly encouraging, given the current response rate for chemotherapy treatments in glioblastomas is only at 5%. This compares to the 33% response rate of dabrafenib and trametinib, and 40% response rate in patients younger than 40 years.
The patients selected for the trial were those with tumours carrying a genetic mutation known as v600E in the BRAF gene, a mutation found in only 2-3% of patients with high-grade gliomas. It is found in up to 60% of patients with certain types of low-grade gliomas, and 13 patients suffering with this form of glioma were included in the study. Nine of these patients had an objective response to treatment with the drug combination, a response rate of 69%.
Gliomas are tumours that originate in the glial cells of the brain or spinal cord, causing headache, confusion, memory loss, speech problems, and seizures. They make up around 80% of all malignant brain tumours. While some are slow-growing low-grade gliomas, others are aggressive high-grade gliomas, which are difficult to remove and almost always recur. Few significant advances to treating gliomas have been made in recent years.
