In new research this week, an experimental treatment seems to have helped beat back a woman’s advanced pancreatic cancer. The woman’s tumours have since substantially shrunk in size and she has remained in stable health a year after the treatment — results that hold promise for a new approach to these kinds of often fatal cancers.
The treatment is a form of immunotherapy, a recently developed method of fighting cancer. The premise is simple enough: teach the immune system to kill cancer cells that it normally wouldn’t. Often, this is done by genetically altering T-cells to carry new receptors on their surface, receptors that allow the cells to now recognise a protein, or antigen, found in certain cancer cells.
Immunotherapy treatments have succeeded in improving many people’s odds of survival against advanced blood cancers like Leukemia. But it’s proven harder to train the immune system to go after solid tumours, which can form anywhere in the body. Researchers at the Providence Cancer Institute, however, believe that they may have found a way around these hurdles, at least for some patients.
Their earlier research has shown that some T-cells can naturally identify a particular mutant version of an antigen found in some solid tumours, known as KRAS G12D. They theorised that the T-cells of people with the right genetic compatibility could be reprogrammed to target tumours that contain this mutant KRAS. The patient in this new study, identified as Kathy Wilkes by the Associated Press, turned out to have just such a cancer, and she was genetically compatible to boot.
Last June, Wilkes received a single infusion of her T-cells, which were altered to carry two receptors important for recognising the mutant antigen in the lab and then grown en masse. Six months later, her metastatic tumours had seemingly shrunk by 72% per cent, while the altered T-cells continued to linger, accounting for 2% of circulating peripheral T-cells in her system. And recent check-ups haven’t found any signs of her condition worsening. The team’s findings were published Wednesday in the New England Journal of Medicine.
“It’s really exciting. It’s the first time this sort of treatment has worked in a very difficult-to-treat cancer type,” Josh Veatch of the Fred Hutchinson Cancer Research Centre, who is not affiliated with the research, told the AP.
This improvement is obviously not a full remission. But following conventional treatment with chemotherapy, radiation, and surgery, Wilkes’ cancer began to spread outside her pancreas, leaving her with few options and little chance of long-term survival. Reportedly, she herself sought out doctors at the Providence Cancer Institute after hearing about their research. And the team was able to perform the procedure with approval from the Food and Drug Administration.
Encouraging as these results are, they come from a sample size of one. And an earlier patient of the institute failed to show any improvement following treatment. So it will take more clinical research to confirm that this method really can help compatible patients. Elsewhere, other research teams are working on their own ways to boost the potential of immunotherapy for solid tumour cancers, such as by using cancer-killing viruses in conjunction.