Trials carried out in Scotland on people with one of the most aggressive and deadly forms of melanoma showed that the new treatment combination improved their life expectancy compared with existing approaches.
Whereas previously those with the condition had a short life expectancy – in most cases less than a year – they can now live for 22 months, the new research found.
The study was led by Dr James Larkin, consultant medical oncologist at The Royal Marsden, a specialist cancer treatment hospital in London.
The trials were carried out at the Beatson West of Scotland Cancer Centre by Professor Jeff Evans, right, director of the Institute of Cancer Sciences at the University of Glasgow and professor of translational cancer research.
Some 495 patients took part in the tests, which saw researchers use two medicines – cobimetinib and vemurafenib – for the first time.
The results showed that life expectancy increased significantly. Whereas patients who had used vemurafenib alone lived for an average of 17.4 months, those taking the two drugs together survived for 22.3 months.
Dr Larkin, the lead investigator of the study, known as coBRIM, said the results were “very encouraging” and gave hope to those with advanced melanoma.
He said: “These results are very promising. While progress has been made, there has been a great need to find new treatment options that can extend survival and reduce the likelihood of resistance – a common challenge in tackling this form of advanced skin cancer.
“Cobimetinib and vemurafenib have complementary ways of working together to block the cancer cell survival pathway, significantly extending life, and could reduce or delay resistance. This is a very encouraging development.”
According to the researchers, cobimetinib works together with vemurafenib to target and block two parts of an important pathway involved in cancer cell growth and survival, a chain of proteins known as MAPK. The process can be likened to a canal system, with the treatment acting as floodgates.
Although vemurafenib blocks the so-called “survive and multiply” signals being sent into the cell, resistance means that the floodgate can “burst”. Taken in conjunction with cobimetinib, however, it creates what scientists described as “a more powerful floodgate system”, “reinforcing the blockade”, which leads to inhibited cell growth.
Melanoma UK has welcomed the findings of the coBRIM study as a “significant step forward”, pointing out that preventing disease progression is an “absolute priority” for improving patients’ quality of life.
However, it could be some time before the drugs are routinely administered. Cobimetinib is an investigational medicine not currently available for use anywhere in the UK, while vemurafenib is accepted for restricted use within NHS Scotland, according to the Scottish Medicines Consortium, but not in combination with other drugs.