In a new study, researchers have developed a promising immunotherapy treatment for a deadly form of adult brain cancer called glioblastoma.
The research was conducted by a team from McMaster University and the University of Toronto.
The treatment is a type in which a patient’s T cells, which are a kind of immune cell in the blood, are changed in the laboratory so that they will bind to cancer cells and kill them.
In this case, the treatment called chimeric antigen receptor T cell (CAR-T) therapy involves genetically engineering a patient’s T cells to give the cells the ability to target and bind to a specific protein called CD133 in glioblastoma cells directly and eliminate them.
When used in mice with human glioblastoma, the new therapy was considered a success due to reduced tumor burden and improved survival.
The data from this study has led to the formation of a new Hamilton-based start-up brain cancer immunotherapy company called Empirica Therapeutics.
The company aims to run clinical trials in recurrent glioblastoma patients for the lead program CD133-specific CAR-Ts and other therapies by 2022.
Upon initial diagnosis, glioblastoma patients undergo aggressive treatment, including surgery to remove the tumor, radiation therapy, and chemotherapy.
However, cancer relapses in less than seven months, resulting in less than 15 months overall median survival.
Almost all the glioblastoma tumors come back as a more aggressive recurrent tumor, which has no standard-of-care treatment.
Previously, the team had identified that the protein is a marker of cancer stem cells that have the properties necessary to grow glioblastoma tumors that are difficult to treat.
In the study, they tested if specific targeting of CD133+ glioblastoma with cutting-edge immunotherapy drugs could stop tumor growth.
They also looked at the safety of CD133-targeting therapies on normal, non-cancerous human stem cells.
Researchers subsequently designed three types of treatments and tested them both in the lab and in mice.
The first treatment is the novel human synthetic IgG antibody, which can simply bind to CD133 protein on glioblastoma cells and halt the growth of the tumor.
The second is a dual antigen T cell engager antibody, which uses the patient’s own immune T cells to eliminate the CD133+ glioblastoma. The third is CAR-T therapy.
They found that CAR-T therapy had enhanced activity compared to the other two methods in preclinical models of human glioblastoma.
The researchers hope that the approach of specifically targeting glioblastoma cells with CAR-T therapy will give the patients a better quality of life and increase their chances of survival.
They are exploring combinatorial strategies next along with CD133-specific CAR-Ts to block glioblastoma tumor recurrence completely.
The study is published in Cell Stem Cell.
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