In one of the first trials of a genetically engineered vaccine, a team at the Johns Hopkins Oncology Centre in Baltimore, Maryland, succeeded in activating patients' immune systems.
The vaccine was given to 18 patients with advanced kidney cancer to test its safety and effectiveness over an eight-year period. One patient, whose tumour continued to grow and spread to his lungs after surgery, showed a substantial improvement for several months after receiving the vaccine.
Although the rest showed no signs of remission, all had measurable immune responses. Many patients died within the first year of the trial.
The findings are reported in the journal Cancer Research.