In a small clinical trial of a personalised kidney cancer vaccine, the disease did not return in any of the nine patients who received it. Participants were followed for an average of three years and four months after surgery, with results considered encouraging, although the small number of participants means it is not possible to state with certainty that the vaccine prevented the disease from returning.
Scientists developed an experimental vaccine that teaches the immune system to recognise cancer cells. The process involves analysing each patient’s tumour, selecting unique protein fragments, known as neoantigens, and using them to create the vaccine. The aim is to stimulate the body’s immune system to attack the individual’s specific cancer.
Nine people with clear cell kidney cancer, the most common form of the disease in adults, took part in the study. Seven of the patients were in stage three, and two in stage four of the disease. All had their tumours completely removed by surgery, and at the time of vaccination, they had no visible signs of disease, but were at high risk of it returning. The scientists hoped that the vaccine would train the immune system to destroy any remaining cancer cells that were too small to be detected by standard tests.
An immune response developed in all nine patients. In seven of them, T cells activated by the vaccine were able to recognise the patient’s own tumour. Researchers warn that the results must be interpreted with caution. David Braun from Yale University and Toni Choueiri from the Dana-Farber Institute led the study.
Because the study did not have a control group, it is not possible to determine how many patients would have had a recurrence without the vaccine. The study cannot confirm whether the addition of the immunotherapy drug ipilimumab, which was given to five patients, further improved the outcome. The creation of a vaccine for kidney cancer is a particular challenge, as these tumours typically have fewer mutations than, for example, melanoma, which means a smaller number of potential targets for the vaccine. The research team successfully produced a vaccine for each participant.
Follow-up showed that the immune response lasted for years. A key step was confirming that the T cells activated by the vaccine could recognise actual tumour cells, not just their components in the laboratory. In seven of the nine cases, they were able to confirm that the vaccine-activated T cells could recognise the patient’s own tumour.
The phase one study was primarily focused on safety and tolerability. The most common side effects were mild, such as reactions at the injection site and temporary flu-like symptoms. No participant experienced severe side effects. It remains unclear whether the vaccines truly improve treatment outcomes. A larger study, INTerpath-004, is currently testing a second personalised vaccine based on mRNA technology in combination with immunotherapy. The study was published in the journal Nature.
