Bengaluru: Renowned oncologist and Pulitzer Prize winning author Dr Siddhartha Mukherjee said targeted cellular therapy is the culmination of cancer research.
“Cancer treatment is undergoing a transformation today,” said Mukherjee, while speaking at ThePrint’s Off The Cuff in Bengaluru Tuesday.
Traditional treatments such as chemotherapy and radiation are administered to kill cells. But there has been a paradigm shift, he said, in the treatment of cancer since the 1990s when scientists began discovering the root genetic cause of tumour development – genetic mutations.
Mukherjee was in conversation with ThePrint’s Editor-in-Chief Shekhar Gupta and Managing Director of Biocon Limited Kiran Mazumdar Shaw. He spoke about the current state of cancer research, how it has grown over the years, ethics surrounding field trials of new treatments, and upcoming research into cellular therapy.
A cancer expert, Mukherjee is the author of the critically acclaimed book, The Emperor of All Maladies: A Biography of Cancer, which won the 2011 Pulitzer prize for general non-fiction. It has also been listed as one of the 100 most influential books of the last century by Time magazine. The book explores the history and evolution of cancer as a disease and the various methods that humans have been using to treat it.
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Cellular therapy
Cell therapy treatment targets specific cells by weaponising them to fight cancer through an immune response, as opposed to only using drugs or pills to treat it.
“We now know that the root cause of cancer is mutations and alterations in genes and the DNA, especially the genes that control how cells divide or obtain nutrients. Once this was determined, there were attempts to find new treatments that would strike at the Achilles heel of cancer,” he explained.
These new treatments include both chemicals as well as antibodies.
Mukherjee also elaborated on how cancer cells grow by avoiding immunosurveillance — a term used to describe the process by which immune system cells look for and recognise foreign pathogens, pre-cancerous as well as cancerous cells in our bodies.
“We can weaponise a cell by educating it to go kill cancer. Not all cancers are amenable to this. Blood cancers like leukaemia and lymphoma have had successes, while some ‘solid’ cancers such as pancreatic or lung cancer hasn’t shown success with this treatment,” said the biologist.
Addressing the present state of cancer research in India, Shaw said the cost to treat the disease should be affordable.
“There is a lot of work being done in oncoimmunology. But the cost of delivering cutting-edge therapies is very high. It can go up to a million dollars and even the West cannot afford it. We want to bring down the costs of such research and treatments in India,” she added.
‘Little public trust in science’
Speaking about the rising anti-vaccine movement across the world, most prominently in the US, Mukherjee said there has been little public trust in scientific processes and this needs to be “fixed”.
“I would say that the medical community has become complacent in not communicating the importance of vaccines to the public. Remember the time when Polio vaccine was invented. People wouldn’t get out of their houses because of fear of contracting the disease. But the vaccine’s success changed everything,” he said.
Mukherjee also said that both the medical community and people outside of it take successful medicinal innovations for granted.
“Scientists and medical researchers should communicate the marvel of vaccines every day to the public to remind them about how lives have been changed because of it. It’s only when scientists engage with the public regularly, communicate efficiencies and also potential mishaps that the public will understand and place their trust in science,” he explained.
Ethical dilemma
Talking about ethics in cancer research, Mukherjee said some paediatric cancers are especially challenging since children cannot provide consent for a new treatment.
He further elaborated on how cell therapy can backfire. “One of the reasons why the Food and Drug Administration had halted a set of trials was because the patients were dying. Not because the drugs had under-performed, but because they had over-performed, triggering the body’s immune system to attack itself after it dissolved the cancer,” he said.
Such complexities would need to be communicated to patients so that informed consent can be obtained.
Addressing the suspicion towards western drugs in India, Mukherjee recalled India’s colonial past and some “racist” medical experiments in the US which could be the likely reason behind such apprehensions.
Risk mitigation
In the absence of cell therapies, several cancers like leukaemia, have a 100 per cent mortality rate, said Mukherjee.
“A multiple myeloma drug that will almost certainly be approved by the FDA will result in about 80 per cent of such patients achieving remission. Which is already a big step. And among that 80 per cent, 50 per cent of the total who initially had a 100 per cent mortality rate will live for 2-3 years, sometimes even 5-6 years,” he added.
Targeted therapies showed similar numbers.
Mukherjee also distinguished between the “science” and “art” of medicine while speaking about how dampeners can help contain the body’s autoimmune response by evaluating when to increase or decrease their levels.
Cancer, he later added, follows the laws of evolution and natural selection. “Any therapy is a mathematical game between the body and its cancer. If a therapy has the capability to kill 1 billion cells, there is a likelihood of 1 billion cells becoming resistant and causing relapse. If it can kill 1,000 cells, then 1,000 cells could become resistant. Risk mitigation is all about finding the exact balance in situations like these, and the only way we can know more is through science and appropriate clinical trials for the right kind of patients,” explained the cancer expert.
In the pyramid of cancer treatment, Mukherjee said prevention (such as those taken by the government in the form of human papillomavirus or HPV vaccines) forms the base layer, early detection (done by public-private partnership) the middle, and treatment at the top. The pinnacle of cancer treatment today is cell therapy, he added.
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