Immunotherapy is a great advance in the fight against cancer and has obtained good results in some tumors such as melanoma or lung cancer, but some types of cancer do not respond to immunotherapy treatments. Now, however, a new immunological drug in the experimental phase has demonstrated its efficacy in treating glioblastoma -the most frequent and aggressive brain tumor- in a preclinical study that has been carried out with in vitro and in vivo models, using samples from patients with glioblastoma.
Preclinical studies carried out by scientists from the Vall d’Hebron Institute of Oncology (VHIO), which is part of the Vall d’Hebron Campus, led by Dr. Joan Seoane, and with the support of the Spanish Association Against Cancer (AECC), have verified that this drug manages to induce a regression of glioblastoma, according to the results published in the journal Molecular Cancer Therapeutics.
Dr. Joan Seoane, co-director of the VHIO Preclinical and Translational Research Program and Professor Icrea, stated that “this study is especially important because an immunotherapy has been found to work in the treatment of glioblastoma”. “If we take into account that it is the most common and aggressive primary brain tumor, and that there is a great need to develop new treatments against this disease, I believe that the results of this preclinical study, which will now be validated in a clinical trial with patients , they are very relevant”, he adds.
Recruit immune cells to kill cancer cells
To make immunotherapy effective in less immunogenic tumors, bispecific antibodies (TCBs) have been developed that help recruit T-cells from the immune system to kill tumor cells. The bispecific antibodies bind to the tumor cells on the one hand and to the T cells on the other so that the latter come into contact with the tumor and destroy it.
“An immunotherapy has been found to work in the treatment of glioblastoma, the most common and aggressive primary brain tumor”
To develop these antibodies, it is necessary to have specific targets for tumor cells that make these antibodies bind only to cancer cells and do not cause the immune system to also attack healthy cells. “In the specific case of glioblastoma, there is a mutation in the EGFR gene, known as variant III, which is specific and specific to this type of tumor and is not shared by any healthy cell. This makes it an ideal target for the development of targeted therapies, although it is only present in 25% of glioblastomas”, explains Dr. Seoane.
Taking this characteristic into account, a new antibody has been developed, EGFRvIII-TCB, which recruits T cells towards tumors that express the EGFRvIII mutation. “When the mutation is not present, the antibody does not work and therefore only patients with tumors that express EGFRvIII will benefit. This is, therefore, a new drug necessary for the development of precision medicine, in addition to being a very safe treatment since it does not act on healthy cells that do not express the mutation”, concludes Dr. Seoane.
Thanks to the good results achieved in the preclinical validation phase of this new VHIO drug, a phase I clinical trial has been launched for which patients are already being recruited, and whose objective is to verify its safety and efficacy in people and determine the most appropriate dose.
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