BENGALURU: This is the story of J K, a 55-year-old gentleman, who is a patient of Stage IV Renal cell cancer (a type of kidney cancer), which had spread to liver, lymph nodes and bone. He had earlier received treatment with surgery and targeted therapy with Sunitinib. Unfortunately, he did not respond well to the standard treatment, and had rapidly progressing disease in four months. The disease progression led to worsening of his symptoms and his general condition deteriorated very rapidly. He became very sick and his chances of survival were very poor.
The family was distraught, and wished to try any new advanced therapy available to save his life. This was the time when a new immunotherapy drug called Nivolumab had just become available. After a lot of deliberations, he was started on treatment with immunotherapy injections. His condition improved dramatically in seven weeks after only three immunotherapy injections.
A PET-CT scan after this showed that the cancer had significantly melted away. He was continued on treatment for one year, and repeated scans were negative for cancer. After this, his treatment was stopped completely over a year ago, and he continues to be cancer free.
This dramatic response to immunotherapy was very surprising, but heartening to see! This kind of dramatic response has never been seen with any previous treatments for this cancer. This can only be explained due to activation of his immune system due to the immunotherapy, leading to destruction of the cancer cells in his body.
In recent times, we have seen the advent of immunotherapy in treatment of many cancers. This is revolutionising cancer management and helping cancer patients survive longer with good quality of life, and also potentially curing some advanced cancer patients. The understanding of our body’s immune system and its role in cancer has led to new discoveries. It is now understood how cancer cells suppress our body’s immune system by suppressing the main cancer fighting cells, which are the ‘T’ lymphocytes. The discovery of these inhibitory proteins - called the CTLA4 and the PDL1 proteins is instrumental in this understanding. Cancers increase the expression of these proteins leading to inhibition of the ‘T’ lymphocytes. This enables the cancer cells to grow out of control without being killed by our immune system.
This discovery has been so profound, that the 2018 Nobel prize in medicine was jointly given to James P. Allison and Tasuku Honjo for their discovery of cancer therapy by inhibition of negative immune regulation. They discovered that by using medicines called check point inhibitors, it was possible to release the inhibition (in other words release the brakes) on the ‘T’ lymphocytes; thus making them active to kill the cancer cells.
The use of the checkpoint inhibitors or immunotherapy drugs has now come to the forefront in the management of many cancers. These immunotherapy drugs are now being used in the treatment of many cancers like melanoma, renal cell cancer (kidney cancer), lung cancer, urinary bladder cancer, head and neck cancers, liver cancers, hodgkin’s lymphoma and some colon and stomach cancers.
The use of immunotherapy in cancers is expanding in both- the types of cancers, and also in earlier lines of treatment. The major advantage of immunotherapy drugs is that those patients in Stage IV disease who respond, can have a prolonged and long duration of response. This is different from the previous treatment options like chemotherapy which worked only for a limited time. The other significant advantage is that they do not have the side effects of chemotherapy. They can be used safely even in the elderly population, and also in patients where chemotherapy would not be safe to give.
The limitation of immunotherapy at present is that it works in selected patients. Responders can have long term survival; but there are many patients who do not respond. At present, there are no biomarkers to help us select patient who would respond well. There is a lot of research going on to identify the patients who would respond better, and also in methods to further improve the response.
Immunotherapy has become a ‘game changer’ in the management of cancer. The concept of unleashing the power of the immune system against cancer is very attractive and immunotherapy is going to dominate cancer management in future.
– Consultant, Cancer Care, Manipal Hospitals, Bengaluru