Heating solid tumours during CAR-T cell therapy could increase chance of success, researchers from the UCLA Jonsson Comprehensive Cancer Center have found. Combining a heating technique called photothermal ablation with the infusion of CAR-T cells suppressed melanoma tumour growth for up to 20 days in mice. A third of these were still free of tumours after that point.

Traditionally, CAR-T therapy has been less successful with solid tumours than other variants because those tumours have a protective microenvironment which makes it harder for the T-cells to remain activated within the tumour.

Photothermal ablation is a minimally-invasive technique using laser energy to heat and kill cancer cells, and is already used in several other cancer treatments. Raising the temperature to around 40 degrees Celsius expands blood vessels associated with the tumour, enhancing T-cell growth.

In the future, the researchers will continue to test the effectiveness of the technique in animals, and better optimise heating duration and temperature before human trials can begin.