Test can personalise use of immunotherapy and chemotherapy for cancer

Matching cancer patients to treatment based on their levels of a key immune protein may allow doctors to select those who would benefit most from the combination of immunotherapy and chemotherapy, researchers report.

Their study showed that patients with head and neck cancer benefited from different treatments depending on the results of a test measuring levels of the protein PD-L1 in tumours and on surrounding cells.

The researchers hope use of the test will be adopted in guidelines as a way to personalise patients’ treatment by selecting immunotherapy, chemotherapy or the combination of the two depending on PD-L1 levels.

Personalising treatment effectively
Immunotherapy has transformed treatment of head and neck cancer and several other cancer types – but there are still major difficulties in predicting who will respond best and so personalising treatment effectively.

Out of the 882 people involved in the trial, 373 had a moderate PD-L1 score between 1 and 19. Among people in this group, pembrolizumab on its own or with chemotherapy was able to stop tumour growth in many patients.

Three different approaches
The latest results, together with previous findings from the trial, suggest that three different approaches to treatment should be considered, depending on PD-L1 levels. Patients with low levels of PD-L1 are highly unlikely to benefit from pembrolizumab alone, and should receive chemotherapy alone or chemotherapy plus cetuximab.

Previous KEYNOTE-048 analysis showed it was possible to predict who is more likely to benefit from pembrolizumab by testing for PD-L1.

Researchers cautioned that some of the results should be interpreted carefully, given the small number of participants with a PD-L1 score of less than 1, and that additional biomarkers are needed to further select patients who could benefit from pembrolizumab.

A key aspect of precision medicine
Professor Kristian Helin, Chief Executive of The Institute of Cancer Research, London, said, “Smarter tests to identify patients who are most likely to respond to treatment are a key aspect of precision medicine and are urgently needed for immunotherapies. Tests like these can help improve outcomes for patients and make sure we don’t subject people who are unlikely to respond to treatments that won’t benefit them. I hope our new study can improve care for patients with head and neck cancer by helping to optimise treatment depending on test results.” NS Medical Devices