Researchers have presented promising results for a new immunotherapy that could change the future of treatment for glioblastoma, the most aggressive form of brain cancer.
The treatment successfully eliminated tumors in most of the animals that underwent the experiments, a step that could pave the way for clinical trials on humans in the coming years.
Glioblastoma is one of the most difficult cancers to treat, as there is currently no cure. The average survival time for most patients is only between 12 and 18 months.
In this regard, researchers from King's College London and McMaster University in Canada have developed a new version of genetically modified CAR-T cell therapy, an immunotherapy already used to treat some types of blood cancers.
The treatment involves taking immune cells from the patient, then genetically modifying them in the laboratory to be able to recognize and attack cancer cells, before re-injecting them into the patient's body.
This treatment is currently used to treat some patients with leukemia and lymphoma, and has achieved remarkable success in these diseases, but its use against brain tumors remains a major challenge.
The difficulty in treating glioblastoma lies in the fact that it does not remain confined to a single mass, but rather spreads within brain tissues through minute extensions, making its complete surgical removal almost impossible. Moreover, the remaining cells are often able to resist chemotherapy and radiation treatments, allowing the tumor to grow again.
During the study, the researchers tested the new treatment on animal models that mimic the disease in humans, and the results were remarkable; the tumor disappeared completely in 12 out of 13 mice that underwent the treatment, while the animals remained tumor-free for more than four months in one group, and for more than five months in another group.
The new treatment differs from previous attempts in that it does not target cancer cells alone, but also attacks the immune cells that the tumor uses to protect itself from treatment.
To achieve this, the researchers focused on a protein known as GPNMB, found on the surface of cancer cells and on phagocytic cells, which are immune cells that are supposed to protect the body, but which the tumor reprograms to help it grow and resist treatment. After modifying CAR-T cells to recognize this protein, they became able to attack both the tumor and the environment that protects it simultaneously.
Professor Sheila Singh, a professor of neuro-oncology and neurosurgery at King's College London and McMaster University, and the lead author of the study, said that treating this tumor as simply a collection of cancer cells is no longer sufficient, explaining that the tumor forms an integrated ecosystem that includes cancer cells and immune cells that support it, and therefore the new treatment targets both aspects together.
For his part, co-author Shan Grewal said the study's findings suggest that eliminating the tumor may also require dismantling the immune environment that helps it survive, rather than simply attacking cancer cells.
Although the treatment has not yet been tested on humans, researchers confirmed that its results in preclinical studies were strong, which enhances the chances of moving to clinical trials if future studies prove its safety and effectiveness.
This research is part of growing efforts to expand the use of genetically modified T-cell therapy to include brain tumors, following its successes in treating blood cancers.
The study's findings were published in the journal Nature.
