Cancer immunotherapy is one of the most promising fields in new cancer treatment options. But how close are we really to use it as a treatment?
Cancer immunotherapy has recently seen some great advancements and a lot of hope lies in this treatment approach. Cancer immunotherapy is a type of therapy approach that uses the body’s own immune system to target and fight off cancer. This type of therapy can be a vaccine, antibody, or drug. As promising and hopeful as immunotherapy seems, it is far from perfect and the potential side effects along with the high costs mean that it still far from being used as a first of line treatment option.
Deaths in Recent Trial
Many companies have become interested in cancer immunotherapy and there has been a significant shift of research towards this field. However, as recently reported in Science Magazine, one American cancer immunotherapy company is having to explain deaths in a recent trial. Juno Therapeutics had five leukemia patients die from cancer treatment involving genetically engineered immune cells. The company undertook an extremely comprehensive investigation to determine what went wrong in this trial.
Chimeric Antigen Receptor Therapy
The cancer immunotherapy treatment at the heart of the investigation is known as chimeric antigen receptor (CAR)-T therapy. This type of therapy essentially provides the patient’s own immune cells with an added structure on their surface that helps them detect, hone in on and eradicate cancer cells. It is obviously a very promising approach. Juno’s initial trial, dubbed the ROCKET trial, offered this therapy to patients with acute lymphoblastic leukemia (ALL). Juno revealed that cerebral edema was the cause for patients that passed away. They also revealed that in some of these patients, there was an entire collapse of the blood-brain barrier.
In addition, CAR-T cells are very personalized and there is variability from batch to batch that is made uniquely for every patient. Therefore, the variability along with variation in how the cells were processed during the procedure may have also played a role in the deaths. They also found that these cells, when injected, expanded their population much sooner than they were supposed to, and this may have had implications in neurotoxicity. All the factors listed create an additive risk for fatal side effects. These are all lessons that researchers are using to create better-engineered trials.
Fatalities are sometimes a risk when novel therapies are being advanced for many diseases, such as cancer. It is, nonetheless, the promise and hope of these cancer immunotherapies to keep driving research and ongoing clinical trials forward.
Written by Ingrid Qemo, BSc
Reference: Dengler, Roni. Cancer immunotherapy company tries to explain deaths in recent trial. Science Magazine. 2017 November 16. doi:10.1126/science.aar5192.