Researchers find a new way to help immune cells fight cancer for longer

Researchers in the United States have reported a new approach that could help specially prepared immune cells, known as T cells, stay stronger for longer in cancer treatment. In a study at the UCLA Health Jonsson Comprehensive Cancer Center, temporarily boosting a protein called p53 helped T cells kill more melanoma cells in laboratory experiments.

Some cancer treatments take a patient's own T cells, modify them in a laboratory so they can recognise cancer, and then return them to the body to attack tumours.

One challenge with such treatments is that these cells can eventually become exhausted, making them less effective at fighting cancer, the UCLA researchers said. After repeated encounters with cancer, the cells lose their ability to multiply and attack.

To address that problem, researchers treated human T cells with an experimental drug called navtemadlin, which temporarily increases the activity of p53, a protein known for helping to prevent cancer.

The treated T cells showed fewer signs of exhaustion, had more energy and developed characteristics that could help them last longer. When tested against melanoma cells in the laboratory, they were also significantly more effective at killing the cancer cells than untreated T cells, according to the research. The study was published in Frontiers in Immunology.

Kien Vuu, a Los Angeles-based triple board-certified physician and former UCLA assistant clinical professor who was not involved in the research, confirmed that T-cell exhaustion is one of the biggest challenges encountered with these treatments.

Vuu said the practical appeal of the approach is its simplicity. Rather than adding another genetic modification, the drug is added during the manufacturing step, when a patient's T cells are being prepared in the laboratory. If the approach works in further research, he said, it could potentially help T cells remain effective for longer, particularly when treating solid tumours.

Both the researchers and Vuu emphasised, however, that the findings remain preliminary. The experiments involved human cells in a laboratory dish tested against melanoma cells, not animals or patients. The approach will need to be tested in animals and in other types of cancer before moving into clinical trials.

The dose of the drug will also need careful study. The UCLA researchers found that higher doses caused more T cells to die, while lower doses produced the desired effects without substantially reducing the number of healthy cells. Vuu said getting that balance right would be critical.

Vuu said patients should not expect this in the clinic soon, but called it a promising new direction worth following.