A potentially world-changing treatment for cancer has been discovered by scientists from the Fred Hutchinson Cancer Research Centre. Oncologist Stanley Riddell has announced that his team has developed a therapy targeting the immune system may be able to cure over 90% of leukemia cases.
The treatment involves genetically modifying T-Cells – immune cells which hunt down and destroy antigens in the body. Research to determine the effectiveness of the immunotherapy involved taking T-Cells from patients who had between two and five months left to live. The cells were then adapted to produce chimeric antigen receptors, which are proteins that allow the T-Cells to recognise cancer-specific proteins and target them for destruction. These improved cells were allowed to multiply and were then re-injected into the patient, where they were better able to track cancer cells and eliminate them.
After two months it was discovered that 94% of patients suffering from acute lymphoblastic leukaemia had gone into complete remission. This phase one trial is one of the most successful clinical studies to have ever been conducted. Not only do the modified T-Cells eradicate cancer cells, but they also remain in the body for an extended period of time and may help to prevent a relapse.
Unfortunately it is not all good news. Side effects of this treatment can include neurological difficulties, fevers, drops in blood pressure and ‘cytokine release syndrome‘, a condition whereby molecules which aid in cell-signalling and communication during an immune response go into overdrive. This cytokine storm can cause fever, chills, rash, nausea and in extreme cases can even lead to pulmonary edema (fluid in the lungs) and death. In the trial discussed above, two patients died following treatment.
Despite the risks associated with this new therapy, it is often a last resort. For many patients, the benefits seem to significantly outweigh the risks.
One reason for the success of this trial may be that the cancer was of the blood. Unlike other cancers, blood cancers are not contained within tumours. They diffuse through the body and collect in areas local to T-Cells such as the bone marrow, lymph nodes and spleen.
Dr Riddell hopes that the treatment can be refined and improved in order to target more common cancers such as breast and colon cancer. The treatment may not currently be successful for these instances because the cancers manifest as tumours which can essentially create their own micro-environments which can suppress the function of T-Cells.
Thankfully, Dr Riddell already has ideas about how to tackle this problem:
“We’re going to have to learn to combine T cell therapy with things like check point inhibitors, which is another very effective form of immunotherapy for some patients with solid tumors, or to engineer T cells in ways that will allow them to function in that immunosuppressive micro-environment.”
Of course, the treatment also needs to be refined to reduce and even eliminate some of the side-effects mentioned above. There also needs to be longer studies with larger sample sizes in order to properly understand the impact of this technique on the body. We still don’t know how these modified T-Cells will affect other immune system functions, and why this treatment is fatal for some patients is still unclear.
Before we get our hopes up too much we must also note that the research has not officially been published yet, meaning it is still undergoing a peer-reviewed process. Nevertheless, it is hoped that one day immunotherapies such as this will become a cornerstone of modern cancer treatment.