Are We Close to Curing Terminal Cancer? Decoding Immunotherapy

Medicine has come a long way in treating and preventing cancer, but it still remains one of the biggest killers. Lung cancer, which kills almost 1.38 million people a year globally, is among the cruelest.In India, lung cancer cases have shown the highest spurt among all cancers afflicting men, and there has been an increase among women too. Most patients are diagnosed at an advanced stage and even after punishing chemotherapy, they still have a bleak prognosis.Bit by bit, though, medical science is making progress and at the frontier of fighting this cancer globally is immunotherapy.A recent study has shown the immunotherapy drug Pembrolizumab to be twice as effective as chemotherapy.So what is immunotherapy?Immunotherapy is a treatment that harnesses and boosts the body’s own immune system to target and fight diseases and tumours such as cancer.Pembrolizumab is one of the first of a new wave of immunotherapy treatments.Speaking to The Quint, Dr Manish Singhal, Senior Oncologist at Apollo, Delhi, explains:Cancer is peculiar in its ability to escape the body’s immune system by mechanisms which are now better understood by science. Some of these mechanisms are being exploited by immunotherapy to kill cancer cells.Essentially, immunity against cancer exists at all times. A tumour applies molecular brakes or checkpoints on the immune system. Immunotherapy, simply put, releases these brakes so your immune system can recognise and attack cancer cells the same way they fight infections caused by bacteria or viruses.It has worked where even chemo and targeted therapies have failed in certain patients and in certain cancers, such as lung cancer.It first came into the limelight when in 2015, former US President Jimmy Carter received a form of immunotherapy that he called “the key to success” in his fight against melanoma, a type of skin cancer.In India as of now, immunotherapy is approved only for lung and kidney cancer. It generally works in late stage cancer patients only, and is used after chemo fails.Recently, the UK’s National Health Service approved Pembrolizumab as the first treatment given to patients told they have incurable lung cancer.Its biggest success is in lung, kidney, skin, bladder and cervix cancers. Melanoma, in which immunotherapy has also showed high success rates, is rare in India.Immunotherapy has often shown results where other therapies have failed.It could benefit tens of thousands of patients throughout the globe — as many as one-third of those diagnosed at a late stage with the most common form of the disease.Immunotherapy is not a replacement for chemotherapy. Yet. Studies show it to have better results than chemo but more research is needed to have an insight into its full potential.Doctors and scientists are saying that combining cancer immunotherapy not only with standard treatment approaches, such as surgery, radiation and chemotherapy, but even with newly emerging therapies, could lead to novel insights.It is better than chemo only for lung cancer patients whose PDL-1 (a cell surface receptor) expression is more than 50 percent on tumour cells, Dr Singhal explains:Through this technicality, about 70 percent cases are ruled out. It benefits the remaining 30 percent of patients.Dr Manish Singhal, Oncologist, Apollo HospitalThere are currently two players in the market for immunotherapy drugs. Nivolumab (opdyta) by American pharmaceutical company Bristol-Myers Squibb (BMS) has been in India for the last six months. And Pembrolizumab (keytruda) is a recent launch by Merck.These are part of a class of new medications called checkpoint inhibitors that disable the brakes that keep the immune system from attacking tumours.We currently have 5-6 patients undergoing the treatment and it is routine for those who can afford it.Dr Manish Singhal, Oncologist, Apollo HospitalThere is no specialised centre required to do this as it is a commercial drug available in every hospital that treats cancer patients.But with a cost of Rs 3-5 lakh per month for the treatment that requires a minimum of one year of therapy, it is expensive.Researchers still don’t know why immunotherapy, hailed as a potential game changer, works in only a minority of patients. Figuring that out is important for clinical as well as financial reasons.As promising as the therapy seems, some worry that the spotlight on immunotherapies may detract from other areas of cancer research, while many others remain unfazed and hail it as a revolutionary way forward to enhance further research.(This article was first published on 5 June 2017.)

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Are We Close to Curing Terminal Cancer? Decoding Immunotherapy

Immunotherapy is the new buzzword in cancer treatment. The Quint decodes what its scope is and what the future holds