The next generation of cancer treatments are all about targeting, finding ways to distinguish and destroy only cancer cells, to as to produce therapies that are much more effective, even against late stage metastatic cancer, and have few side effects. The present staples of chemotherapy and radiation therapy are arduous and only partially effective precisely because they are not very selective. It is easy to destroy cells, but hard to destroy only particular cells. One of the more promising lines of research and development for targeted cell destruction is immunotherapy: making use of the existing capabilities of immune cells and directing them to attack cancer cells:
When immunologist Michel Sadelain launched his first trial of genetically engineered, cancer-fighting T cells in 2007, he struggled to find patients willing to participate. Studies in mice suggested that the approach - isolating and engineering some of a patient's T cells to recognize cancer and then injecting them back - could work. But Sadelain did not blame colleagues for refusing to refer patients. "It does sound like science fiction," he says. "I've been thinking about this for 25 years, and I still say to myself, 'What a crazy idea'."
Since then, early results from Sadelain's and other groups have shown that his 'crazy idea' can wipe out all signs of leukaemia in some patients for whom conventional treatment has failed. And today, his group at the Memorial Sloan Kettering Cancer Center in New York City struggles to accommodate the many people who ask to be included in trials of the therapy, known as adoptive T-cell transfer.
[This is] the promise of engineered T cells - commonly called CAR (chimaeric antigen receptor) T cells - for treating leukaemias and lymphomas. The field has been marred by concerns over safety, the difficulties of manufacturing personalized T-cell therapies on a large scale, and how regulators will view the unusual and complicated treatment. But those fears have been quelled for some former sceptics by data showing years of survival in patients who once had just months to live. "The numbers are pretty stunning. Companies have clearly decided that it's worth the pitfalls of how much this therapy is going to cost to develop."