We all know that chemotherapy blasts the body’s immune system, which is the main source of support to a recovering body. So it makes sense not to blast the symptoms of diseases with powerful drugs, but in-stead, encourage the body’s own immune system to attack the problem. After all that is what it is there for.
That is the theory behind the medicine’s new hope, immunotherapy. It has been predicted to be the future of cancer treatment.
Immunotherapy is far from risk free. People with an autoimmune disorder such as rheumatoid arthritis or psoriasis, should not begin such treatment. Researchers have also reported an alarmingly high rate of deaths in early trials, sometimes as high as 25 per cent of all participants. It is not known if all the victims had autoimmune conditions, although they are commonly seen among cancer patients.
More common side effects of immunotherapy include sensations of sickness and nausea so severe that people have had to stop the treatment. Other side effects include fatigue, fever, chills, flu-like symptoms and pain.
What is immunotherapy? An-other name for it is biological therapy. It is a new type of medicine that boosts the body’s own natural defences to fight diseases. Although much of the pioneering work has centred on cancer, it has also been tested on neurological problems – schizophrenia and Alzheimer’s disease.
Monoclonal antibodies – Our immune system naturally produces proteins, these are called antibodies and they fight infection. Monoclonal antibodies are produced in a laboratory and mimic the body’s own natural defences. They can be used as targeted therapy to block abnormal proteins in cancer cells or to ‘flag’ cancer cells to help the immune system ‘see’ and destroy them.
Non-specific immunotherapies – These often augment chemo/radio therapy. However, they may also be used as the primary cancer fighter. These therapies include interferon, a protein made in the laboratory and interleukins, both of which boost the immune system by making more cancer fighting cells.
Oncolytic virus therapy – This harnesses genetically modified viruses to kill cancer cells. The first oncolytic virus to treat melanoma or skin cancer was approved by the US FDA in 2015.
T-cell therapy – This takes T cells from the patient’s blood and then adds receptor (chemical signalling) proteins to T cells to help them recognise cancer cells, before the modified cells are put back into the bloodstream. This is known as ‘chimeric antigen receptor T-cell therapy’ or CAR-T.
Cancer vaccines – These vaccines introduce antigens into the body to help the immune system identify cancer cells and kill them.
The US National Cancer Institute says that fatal allergic reactions toimmunotherapy are rare, but researchers at the UT Southwestern Medical Centre in Dallas, Texas, reckon that these reactions might be common in patients who already have autoimmune conditions such as rheumatoid arthritis, psoriasis and polymyalgia. More than half of these patients could suffer severe and irreversible toxic reactions affecting many organs.
However, the negative reports are unlikely to hold up the therapy. It has won the American Society of Clinical Oncology (ASCO) Advance of the Year award for 2016. “There is now evidence that immunotherapy works against a range of cancers”, the accolade reads.
Immunotherapy might improve survival from pancreatic cancer, one of the more lethal forms of cancer, by as much as 75 per cent, say researchers at the Fred Hutchinson Cancer Research Centre.
The immunotherapy drug nivolumab could be a ‘game changer’ for people with lung cancer. In a trial by researchers at UT Southwestern Medical Centre, 292 lung cancer patients were given nivolumab and 290 were given a chemotherapy drug. The one year survival rate among the immuno-therapy patients was 51 per cent vs 39 per cent in the chemo group. Nivolumab could also improve survival from head and neck cancers. Patients taking the immunotherapy drug were more than twice as likely to still be alive a year later, compared with patients receiving conventional treatment.
Twenty seven of 29 leukaemia patients went into remission after they were given the CAR-T immunotherapy treatment. This consists of T cells modified to express chimeric antigen receptors (CAR) that identify and kill neoplasms (cancer) on B cells (immune cells that produce antibodies).
Researchers have dug a bit deeper and found that patients, far from being cured, only lived a further three months when compared with those given chemotherapy.
However, this is a genuine breakthrough. Immunotherapy may be conventional medicine’s best hope for combating cancer, but longer term trials need to be carried out before its true effectiveness can be known. It is not for every person with every type of cancer.
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