A UK study has identified two genes that regulate the response of cancer to immunotherapy and could be used as biomarkers to predict patients’ response to therapy. 

Immunotherapy is a widely used therapy that uses the patients’ own immune system to fight cancer. But for some cancers, especially solid tumours, immunotherapy effectiveness is below 35% and the reasons why areunclear. 

Researchers at Wellcome Sanger Institute used cancer cells from patients and grouped them with cells from their own immune system. Using the genetic-editing tool CRISPR to delete specific genes, they found that whentwo cancer genes were absent, the immune cells were more capable of killing the tumour cells.  

The vulnerability of cancer cells was higher when both genes were absent simultaneously. Tumours in genetically engineered mice lacking these genes responded better to immunotherapy – tumours grew more slowly and regressed more frequently – supporting their role in the efficacy of this therapy. Data from patients also aligned with these findings. 

“We saw that patients whose tumours have low expression of these genes are more likely to benefit from immunotherapy. In the future, these new biomarkers could guide doctors by predicting who will respond to treatment and enable more personalised cancer care,” said Matthew Coelho, senior author of the study published in Cell Reports Medicine and researcher at the Sanger Institute.