These are partial results from an ongoing study involving around 1,100 patients that have attracted attention and sent pharmaceutical companies racing to the stock market. The treatment, which has been shown to be effective against advanced skin cancer, is an individually tailored vaccine that causes the immune system to kill tumour cells.
Patients receive the new treatment in combination with another drug, a PD-1 inhibitor. Results from a smaller phase 2 study have previously shown that the combination slows the recurrence of the tumour and that the tumour does not spread in the same way.
Not published
The results of the new, larger study of mRNA therapy have not yet been published in a scientific journal, but the companies developing it, Merck and Moderna, have announced that the results are positive.
Lars Ny at Sahlgrenska University Hospital in Gothenburg is the responsible physician for a number of Swedish patients participating in the study.
"This is big news. We've been burned so many times with similar treatments. This is precision medicine at its best," he says.
The treatment is called an mRNA vaccine, but it is not a vaccine given to prevent melanoma from occurring, but rather an additional treatment for established disease. In short, it involves using a piece of the patient's tumour to map which tumour mutations are present and which ones the vaccine targets. This is done in the US.
One month
The individual vaccine is then sent back to the patient. The vaccine then trains the immune system so that it can attack new cancer cells.
The process of developing the vaccine takes a month, and the fact that it can be done within that time window is fantastic, says Lars Ny.
Exactly how the process works is a trade secret and what the treatment might cost if it is approved in the future cannot be answered today.
The logistics are very extensive, says Lars Ny.
Other studies are underway with similar treatments in areas such as pancreatic cancer and bladder cancer.
The hope is that it can work on several types of cancer.
Patients in the phase 2 study experienced only mild side effects in the form of fatigue and a swollen and stiff arm.
The incidence of malignant melanoma is increasing in Sweden and globally. There is consensus that UV radiation is the most important environmental factor for the development of melanoma in the skin. Solar radiation is the dominant UV source.
In 2024, approximately 5,200 patients in Sweden were diagnosed with malignant melanoma. Approximately the same number were diagnosed with pre-stages of the disease.
Every year, around 500 patients die from melanoma in Sweden.
Source: Regional Cancer Centers
