Nearly 60% of people with advanced melanoma were found to have reduced tumor sizes after being subjected to ipilimumab and nivolumab.
An international trial on 945 patients found that treatment with ipilimumab and nivolumab stopped the cancer advancing for nearly a year.
The immune system is a powerful defense against infection. Cancer, which is a corrupted version of healthy tissue, can take advantage of brakes which are naturally built in to stop attacks on its own tissues and deplete the immune system.
Ipilimumab, which was approved as an advanced melanoma treatment by the UK's health service last year, and nivolumab both take the brakes off.
Dr. James Larkin, a consultant at the Royal Marsden Hospital said, "By giving these drugs together you are effectively taking two brakes off the immune system rather than one so the immune system is able to recognise tumors it wasn't previously recognizing and react to that and destroy them."
But the great hope is these immunotherapies will prove to be effective treatments for a wide range of cancer types.