A new immunotherapy can greatly extend the lives of a proportion of people with advanced head and neck cancer, with some living for three years or more, a major new clinical trial reports.

Overall, the drug pembrolizumab had significant benefits for patients, with 37% of patients who received it surviving for a year or more, compared with only 26.5% of those on standard care.

But the results were particularly exciting among the group of people who did respond to pembrolizumab—with a median length of the response of 18.4 months, compared with five months for standard care.

International clinical trial

The large international clinical trial was led by a team at The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust, and involved 97 medical centres in 20 countries. The trial was sponsored and funded by Merck & Co., Inc., known as MSD outside the United States and Canada, and the results are published in The Lancet today.

The drug was evaluated in a trial of nearly 500 patients with very advanced head and neck cancer that had spread around the body and had already become resistant to platinum chemotherapy, the first-line treatment for the disease. Some 247 patients were randomised to pembrolizumab and 248 to the standard of care—chemotherapy or the targeted agent cetuximab.

When chemotherapy or targeted therapies stop working, treatment options for people with advanced head and neck cancer are limited, and they are normally expected to survive for less than six months.

Patients on the trial who received pembrolizumab survived for a median of 8.4 months with pembrolizumab, and 6.9 months with standard treatment. But a minority of patients responded extremely well to pembrolizumab 36 patients saw their cancer partially or completely disappear, and some are still cancer free three years after first receiving the drug.

Pembrolizumab also caused fewer serious side-effects than currently approved drugs 13% of people who received the immunotherapy experienced serious side-effects, compared with 36% of people given standard treatment.

Researchers at The Institute of Cancer Research (ICR) and The Royal Marsden hope pembrolizumab could be a much needed smarter, kinder treatment option for people with advanced head and neck cancer.

Pembrolizumab works by taking the brakes off the immune system's ability to attack cancer cells, and is already approved for use in some people with lung cancer, skin cancer and lymphoma.