Cancer ‘Vaccine’ Remembers Disease & Fights it Years Later
A revolutionary new cancer treatment that remembers the disease and acts like a watchman to prevent it ever returning is being developed by scientists.
Researchers are engineering immune cells so that they not only boost the body’s own natural defences to fight tumours, but stand guard for a lifetime – acting effectively like a vaccine.
Scientists say it is like having a “living drug”, which is constantly vigilant to the return of cancer and quickly removes it from the body.
A new study, presented at the American Association for the Advancement of Science annual meeting in Washington, has proven for the first time that engineered “memory T-cells” can persist in the body for at least 14 years.
Professor Chiara Bonini, a haematologist at San Raffaele Scientific Institute and Vita e Salute San Raffaele University in Milan, said: “T-cells are a living drug, and in particular they have the potential to persist in our body for our whole lives.”
“Imagine when you are given a vaccine as a kid and you are protected against flu or whatever for all of your life. Why is that? It’s because when a T-cell encounters the antigen and gets activated, it kills the pathogen but also persists as a memory cell.”
“Imagine translating this to cancer immunotherapy, to have memory T-cells that remember the cancer and are ready for when it comes back.”
In a trial at a Milan hospital, ten patients who had bone marrow transplants were also given immune-boosting therapy which included the memory T-cells. They were found to be there 14 years later.
Immunotherapies, which harness the body’s own immune system, look set to replace cell-damaging chemotherapies. But one of the biggest challenges is to make these changes last long enough that the cancer cannot come back.
The Milan study proved for the first time scientists have shown that these cells can survive in the body well beyond the original cancer treatment.
Prof Bonini and colleagues are now working on a new wave of immune cells that can use sensor molecules known as antigen receptors to track down and wipe out a wide variety of types of cancer. When the cells are combined with the memory cells it should produce a treatment which effectively vaccinates the body against cancer.
“When a T-cell encounters the antigen and gets activated, it kills the pathogen but also persists as a memory cell,” she said. “Some of these memory T-cells will persist through the entire life of the organism, and so if you encounter the same pathogen – say if the same strain of flu comes back ten years later – then you have memory T cells that remember it from ten years earlier and kill it quickly so you don’t even know you’re infected.”
Daniel Davis, professor of immunology at the University of Manchester, said it was an “important advance” in cancer treatment.
“The implication is that infusing genetically modified versions of these particular T-cells, the stem memory T-cells, could provide a long-lasting immune response against a person’s cancer,” he said.
“Immunotherapy has great potential to revolutionise cancer treatments and this study shows which type of T-cells might be especially useful to manipulate for long-lasting protection.”
“This research area is hot – no question about that. Our detailed knowledge of T-cells is paying off here with important new ideas for tackling cancer.”
In a separate presentation at the AAAS, a team of US scientists showed that their T-cell immunotherapy treatment for leaukaemia had an “unprecedented” success rate of 94 per cent in patients who had been given only months to live.
US scientists said they had achieved “extraordinary” results in early clinical trials.
Stanley Riddell, of the Fred Hutchinson Cancer Research Centre in Seattle, said balancing the different types of immune cells and then equipping them with cancer-sensing molecules had saved the lives of leukaemia patients for whom all other treatments had failed.
His team treated 26 patients whose Acute Lymphoblastic Leukaemia was so advanced they had only two to five months to live. After 18 months, 24 of the patients were in complete remission.
“These are in patients that have failed everything,” Professor Riddell said. “This is extraordinary. This is unprecedented in medicine to be honest, to get response rates in this range from very advanced patients.”