Personalised vaccines have been used to successfully treat melanoma (skin cancer) patients in two small studies.
Researchers used unique differences in each patient’s cancer to design vaccines to spur the immune system into action. The early stage studies included a total of 19 patients, and are published in the journal Nature.
The results will be seen as another step towards personalised therapies, though vaccines are some way off being used as a standard treatment.
Dr Catherine Pickworth, science communication officer at Cancer Research UK, said that the next step will be to test the vaccines in larger clinical trials.
Because of the early stage of the trials, more work is needed to see “if the vaccines are better than existing treatments, if they improve survival, and what their long-term side effects could be.”
Each study looked for faulty molecules from patients’ tumours to use in the vaccines – the first study used a molecule called RNA and the second used protein molecules.
These faulty molecules were personal to each tumour. By including them in the vaccines the researchers aimed to enable the body’s immune system to recognise the tumour and so attack it, keeping at bay any disease that had been left behind.
The first study included 13 patients who had stage III or IV melanoma, 8 of whom had no detectable cancer after surgery. Following vaccination, all of these patients were disease free at the end of the follow up period of 1-2 years.
The 5 remaining patients had relapsed between surgery and the start of the vaccination programme. One of these responded well and remained relapse-free for over 2 years, and another had a partial response.
The second study included 6 patients who each received a series of 7 vaccinations after their melanoma was removed surgically. The tumours were classed as having a high risk of spreading but hadn’t received other treatments.
Four of the patients had stage III melanoma, and after the vaccination the disease had not recurred 25 months later. But the disease did recur in the other 2 patients with stage IV melanoma, though both responded to further treatment using the immunotherapy drug pembrolizumab.
“The promising results show that personalised cancer vaccines designed to treat skin cancer are safe to use, and that for some patients, they can successfully harness the power of the body’s own immune system to kill cancer cells,” Pickworth added.
Ott, P. A. et al. Nature http://dx.doi.org/10.1038/nature22991 (2017)
Sahin, U. et al. Nature http://dx.doi.org/10.1038/nature23003 (2017)