Over the last years, there has been a universal drive to improve the way we treat cancer patients. We use to always opt for radiation, chemotherapy and invasive surgery to find a way to extend patients’ lives. But nowadays, we have made significant advances such as the usage of drugs like imaginib, drugs that target cancer cells by honing in on specific molecular changes seen primarily in those cells.
Finally, we have the newest and ‘fifth pillar’ of the fight against cancer - Car T-Cells, a “living drug” described Renier J. Brentjens, M.D., Ph.D., of Memorial Sloan Kettering Cancer Center in New York, an early leader in the CAR T-cell field.
What is it?
Chimeric Antigen Receptor T-Cells is a drug that uses the patient’s own immune cells as a way to fight cancer. This immunotherapy approach is called adoptive cell transfer. The backbone of CAR T-cell therapy are T-Cells, which are often considered the workhorses of the immune system because of their significant role in orchestrating the immune response and eradicating cells infected by pathogens. These T cells are genetically engineered using a disarmed virus to create receptors on the surface called chimeric antigen receptors - CARs.
How do they work?
When they are injected into the patient with cancer, they start this crash defense build up system and divide and multiply in their millions. Next, they attack and kill the tumour. Following this, the patient is given a "lymphodepleting" chemotherapy regimen that wipes out what is rest of the cancer.
What does this mean for the future?
CAR T-Cells are the first living drug in medicine that stay in the patient for more than 8 years. Scientists have a predicted half life of 15 years after only one infusion. Many trails have been run on children and young adults who were left with no other options after the return of the cancer. It has been widely successful. For example a trail using CD19-targeted CAR T cells showed a complete response - all signs of cancer disappeared in 27 of the 30 patients in the study.
The FDA has already approved the use of this immunotherapy to treat cancer, but there is still a lot of research and trials to be done, especially on adults and especially to reduce the side effects of the therapy. These include some worrisome effects like high fevers. These are the result of a secretion by the T-Cells. However, they have been using steroids and an approved drug called tocilizumab to help the patients recover from these effects and it has been critically successful.
Laura L, Year 12