Studies show continued promise for immunotherapy drugs

Several new immunotherapy drugs are continuing to show benefits across a range of cancer types, according to a slew of new data presented at a US conference.

The drugs, known as checkpoint inhibitors, are available on the NHS for melanoma treatment, and work by provoking a patient’s immune system to target their cancer.  

The new results confirm their benefit for some of these patients, and also suggested they can help certain patients with head and neck cancers, and those with a rare, virus-linked skin cancer called Merkel cell carcinoma.

The CheckMate-141 study looked at the effect of nivolumab on patients with a form of cancer affecting the head and neck, known as squamous cell carcinoma.

These cancers can be treated with platinum-based chemotherapy but often return, at which point patients are generally resistant to further treatments offered. No effective treatments have been approved for these patients in over a decade, said Ohio State University’s Maura Gillison, who presented the CheckMate 141 study results at the 2016 American Association for Cancer Research conference in New Orleans, US.

The trial recruited 361 patients. After a year of follow-up, double the proportion of patients taking nivolumab were alive a year later (36% vs 16%) compared to those offered a different treatment. Trial was stopped early due to the rapid benefit shown by the drug. 

“I’ve treated head and neck cancers for more than twenty years, and this is the first time I’ve had a drug to go to for patients that have become resistant to first-line treatment,” said Gillison. 

Dr Emma King, a Cancer Research UK-funded head and neck cancer expert, said the results could have a “significant impact” for head and neck cancer patients.

“They also reinforce the important shift that we are seeing towards using immunotherapies for cancer treatment.”

The drug is not yet available on the NHS for head and neck cancers, and will need scrutiny for cost-effectiveness, said King.

“Before nivolumab can be used routinely to treat head and neck cancer in the UK, it will need to approved by NICE [the National Institute for Health and Clinical Excellence].”

Another trial, CheckMate069, looked at a combination of nivolumab with a second checkpoint inhiboitor, ipilimumab, for advanced melanoma patients. A new analysis of trial data presented at the conference revealed considerable benefit – 60 per cent of patients taking the combination are still alive two years after starting treatment.

However, the drugs can trigger significant side effects. Almost a third of patients had to discontinue treatment due to the severity of the side effects.

Dr James Larkin, a medical oncologist at the Royal Marsden Hospital, said the results were “very promising”. 

“Both nivolumab and ipilimumab have changed survival expectations in advanced melanoma over the last few years, and these latest data show us that combining these two immunotherapies is an effective two-pronged attack against the cancer.

In a separate study, more than a third of patients with advanced melanoma taking nivolumab alone were found to be still alive after five years – double the figure expected with conventional treatment.

Another trial involved patients with rare Merkel cell cancers. Between 1999 and 2008, just 1500 patients in the UK were diagnosed with this form of skin cancer, which is linked to exposure to a common virus. Again, there are no approved treatments for cancers that have spread, and chemotherapy only provides limited benefit. When given a checkpoint inhibitor drug called pembrolizumab, more than half of patients saw their tumours shrink within three months, according to data presented at the conference.

Although the trial didn’t directly compare the treatment to chemotherapy, the results compare “extremely favourably” with historical data, said study leader Paul Ngheim, from University of Washington Medical Centre in Seattle.

Professor Peter Johnson, Cancer Research UK’s chief clinician, said the results were “impressive”.

“The trial also suggests that patients whose Merkel cell carcinoma is linked to a virus may be more likely to benefit from this treatment, which fits with the idea that the more danger signals there are in a cancer the easier it is for the immune system to recognise it.”

The full results are published in the New England Journal of Medicine.

In other sessions at the conference, checkpoint inhibitor drugs also showed initial signs of promise in patients with advanced bowel cancer, and in liver cancer when used in combination with a treatment called radiofrequency ablation.