An immunotherapy drug has been described a potential “game changer” after a new study found that the drug improves survival in patients suffering from relapsed head and neck cancer. Patients with advance head and neck cancer have poor survival rates since the disease is very difficult to treat.

The study published Sunday in the New England Journal of Medicine found that the drug, nivolumab, improved survival in phase III clinical trials of patients with head and neck cancer. The international team of researchers found that nivolumab improved survival rates with fewer side effects when compared to standard therapy.

There is currently no therapy that improves the survival for patients with cisplatin-resistant relapsed or metastatic head and neck cancers. The patients are expected to live no more than six months. But more than double of patients administered nivolumab were alive a year later.

“Nivolumab could be a real game-changer for patients with advanced head and neck cancer. This trial found that it can greatly extend life among a group of patients who have no existing treatment options, without worsening quality of life,” lead researcher Kevin Harrington from the Institute of Cancer Research in England, said in a statement.

The study involved 361 patients of which 240 had relapsed or metastatic head and neck cancer who were given nivolumab. The other 121 patients were assigned to receive one of three different chemotherapies.

A year later, 36 percent of patients who took nivolumab were alive compared to the 17 percent of those still alive after receiving chemotherapy. Patients who took nivolumab survived for an average 7.5 months while those who underwent chemotherapy survived for 5.1 months on average.

The benefits were more pronounced in patients who tested positive for the human papillomavirus (HPV) who survived for an average of 9.1 months with the drug and 4.4 months with chemotherapy. Patients who tested negative for HPV survived an average 7.5 months with the drug and 5.8 with chemotherapy.

Only 13 percent of patients who took nivolumab had serious side effects compared to 35 percent among those who received chemotherapy.

Patients who received chemotherapy reported that they felt physically, socially and emotionally worse but patients who took the drug remained stable during the course of the study.

“Once it has relapsed or spread, head and neck cancer is extremely difficult to treat. So it’s great news that these results indicate we now have a new treatment that can significantly extend life, and I’m keen to see it enter the clinic as soon as possible,” Harrington said.