Researchers say they have made a big advancement in treating melanoma, the deadliest form of skin cancer for which few good treatments exist in its later stages.
An experimental drug called ipilimumab appears to significantly improve survival in patients in the advanced stages of the disease, new research has shown.
The study, announced this weekend, involved 676 patients with inoperable melanoma who no longer responded to other treatments. They were given one of three treatments:
- ipilimumab by itself
- ipilimumab with another immune-stimulating vaccine, called gp100
- gp100 alone.
After two years, 24 per cent of those given the drug alone or in combination were alive, versus 14 per cent of those given just the gp100.
After one year, 45.6 per cent of people who took ipilimumab were alive after one year vs. 25.3 per cent in the gp100-alone group. At two years, the figures were 24 per cent and 14 per cent, respectively.
Average survival was 10.1 months with ipilimumab, versus 6.4 months for those who got the gp100 alone. That worked out to a 67 per cent improvement in survival for those on the drug, one of the study's leaders, Dr. Steven O'Day of the Angeles Clinic and Research Institute in Los Angeles told the American Society of Clinical Oncology's annual conference.
The results are published online by the New England Journal of Medicine.
While a 10-month survival time may not sound long, the average survival for metastatic melanoma is six to nine months on average, so an additional four months is considered a large difference.
Ipilimumab works by helping the immune system fight tumours. Its target is a specific protein present on certain immune cells, called "cytotoxic T lymphocyte-associated antigen 4" (CTLA-4).
While CTLA-4 normally dampens down the immune system to prevent autoimmune diseases, ipilimumab allows the immune system to unleash the T-cells so they can go out and attack cancer cells.
The ipilimumab did carry side effects in this study: 10 to 15 per cent of patients on ipilimumab experienced serious effects related to the drug's actions on the immune system, including colitis and serious rashes. Most were treatable with high doses of steroids, but 14 deaths were thought to be related to the treatment, including seven from immune system problems.
Yet, the researchers note that's still far fewer deaths than deaths due to the cancer.
Doctors hope that with more refinement, the drug might be use to benefit more melanoma patients, including those in earlier stages of the disease.
The Melanoma Network of Canada said it was excited by the study's results, saying it brings new hope to patients.
"Ipilimumab is the first drug to ever demonstrate a positive impact on survival in melanoma," says Dr. David Hogg, an investigator in the Canadian portion of the study and the director of the Melanoma Oncology Site Group at University Health Network in Toronto.
"We are looking forward to bringing this medication into clinical practice in Canada a quickly as possible."
Ipilimumab is being developed by Bristol-Myers Squibb and is currently not approved by Health Canada. The U.S. Food and Drug Administration has pledged a quick review of the drug and doctors think the drug could be available by the end of this year.
Melanoma is the most serious form of skin cancer. It can spread quickly and once it does, it's almost always fatal if it metastasizes (spreads to other parts of the body).
The survival rate for melanoma is high if it is detected early but once it metastasizes, it is rarely cured and typically kills within a year.
It is estimated that 5,300 new cases of melanoma will be diagnosed in Canada in 2010 and that about 920 people will die of the disease.
