In a new international clinical trial, two cancer drugs developed by US drugmaker Bristol-Myers Squibb are reported to have shrunk tumors in nearly 60% of people with advanced melanoma.

British news media reporting on the proceedings of a meeting of the American Society of Clinical Oncology say an international trial on 945 patients found treatment with ipilimumab and nivolumab to have stopped the spread of the cancer for nearly a year in 58% of cases studied.

Ipilimumab, approved as an advanced melanoma treatment by the UK’s health service last year, is given intravenously every three months and costs around £100,000 for a year. Nivolumab is given every two weeks until it stops working.

Dr. James Larkin, a consultant at the Royal Marsden Hospital, said to be one of the UK's lead investigators, told BBC News: "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 recognize tumors it wasn't previously recognizing and react to that and destroy them.

Another physician, Dr. Alan Worsley, Cancer Research UK's senior science information officer, however, said that combining the immunotherapy treatments also increases the likelihood of potentially quite severe side effects such as fatigue, a rash or diarrhea.

More than half the patients in the trial are said to have had side effects on combination therapy, compared to around a quarter on ipilimumab alone. (dw)