US trials show continued promise for two new skin cancer treatments
Two clinical trials presented at the largest annual cancer conference have raised hopes for new drugs designed to treat malignant melanoma, the most serious form of skin cancer.
The first was a Phase III trial of an immunotherapy drug - treatment that harnesses the power of the immune system to fight cancer. The trial found that previously untreated patients with advanced skin cancer who were given a combination of the immunotherapy drug ipilimumab and the chemotherapy drug dacarbazine lived longer than those who were only given dacarbazine.
The study, which was presented at the annual meeting of the American Society of Clinical Oncology, is the first to show that a combination of immunotherapy and chemotherapy is safe and effective in patients with advanced melanoma.
Researchers recruited 502 patients for the trial - half were given ipilimumab and dacarbazine, while the others took dacarbazine and a placebo (dummy treatment).
They found that patients who received ipilimumab lived for an average of 11.2 months, compared with 9.1 months for those only taking dacarbazine.
After one year, almost half of the patients (47.3 per cent) who took the combination of drugs were still alive, compared with 36.3 per cent of those on dacarbazine alone.
And, after three years, the overall survival rate was 20.8 per cent for the two drugs, compared with 12.2 per cent for dacarbazine alone.
Lead author Dr Jedd Wolchok, director of immunotherapy clinical trials and associate attending physician at Memorial Sloan-Kettering Cancer Centre in New York, said: "This trial's three-year endpoint is significant. No randomised trial for metastatic melanoma has followed patients for this long, and it demonstrates the durability of this survival benefit, now out to three years in this population, and even four years in some cases.
"It's one of the advantages of immunotherapy. The immune system is a 'living drug', able to adapt itself to changes in the tumour that might otherwise lead to resistance when treated with chemotherapy or a pathway inhibitor."
A second Phase III trial focused on a new treatment called vemurafenib, which is a type of drug called a BRAF inhibitor.
All patients on the trial had advanced melanoma with a specific fault (V600E) in their BRAF gene. Vemurafenib is designed to target this specific fault, which is not found in healthy cells.
Half of the 675 patients were given vemurafenib, while the other half received dacarbazine.
After six months, 84 per cent of vemurafenib users were still alive, compared with 64 per cent of patients in the dacarbazine group.
An early analysis revealed that vemurafenib was associated with a 63 per cent reduction in the risk of dying, compared with dacarbazine, as well as a 74 per cent reduction in the risk of disease progression (or death). And, as these results were so promising, patients who had initially been taking dacarbazine were advised to switch to vemurafenib.
Lead author Dr Paul Chapman, attending physician at Memorial Sloan-Kettering Cancer Centre, said: "This is a really huge step toward personalised care in melanoma.
"This is the first successful melanoma treatment tailored to patients who carry a specific gene mutation in their tumour, and could eventually become one of only two drugs available that improves overall survival in advanced cancers."
Professor Peter Johnson, Cancer Research UK's chief clinician, said: "For the first time, we have effective treatments becoming available for melanoma. Vemurafenib, which targets a molecular abnormality in the melanoma cells, and ipilimumab, which allows the body's immune system to attack them freely.
"Both show how the research we have been doing is feeding through into help for patients. It is a first step but a vitally important one, and it encourages us to redouble our efforts for people with this most dangerous type of skin cancer."