Harnessing the Immune System to Fight Cancer
Steve Cara expected to sail through the routine medical tests required to increase his life insurance in October 2014. But the results were devastating. He had lung cancer, at age 53. It had begun to spread, and doctors told him it was inoperable.
A few years ago, they would have suggested. Instead, his chemotherapy oncologist, Dr. Matthew D. Hellmann of Memorial Sloan Kettering Cancer Center in New York, recommended an experimental treatment: immunotherapy. Rather than attacking the cancer directly, as chemo does, immunotherapy tries to rally the patient’s own immune system to fight the disease.
Uncertain, Mr. Cara sought a second opinion. A doctor at another major hospital read his scans and pathology report, then asked what Dr. Hellmann had advised. When the doctor heard the answer, Mr. Cara recalled, “he closed up the folder, handed it back to me and said, ‘Run back there as fast as you can.’”
Many others are racing down the same path. Harnessing the immune system to fight cancer, long a medical dream, is becoming a reality. Remarkable stories of tumors melting away and terminal illnesses going into remissions that last years — backed by solid data — have led to an explosion of interest and billions of dollars of investments in the rapidly growing field of immunotherapy. Pharmaceutical companies, philanthropists and the federal government’s “cancer moonshot” program are pouring money into developing treatments. Medical conferences on the topic are packed.
Hundreds of clinical trials involving immunotherapy, alone or combined with other treatments, are underway for nearly every type of cancer. “People are asking, waiting, pleading to get into these trials,” said Dr. Arlene Siefker-Radtke, an oncologist at the University of Texas M.D. Anderson Cancer Center in Houston, who specializes in bladder cancer. (Description of a situation)
The immune system — a network of cells, tissues and biochemicals that they secrete — defends the body against viruses, bacteria and other invaders. But cancer often finds ways to hide from the immune system or block its ability to fight. Immunotherapy tries to help the immune system recognize cancer as a threat, and attack it.
Doctors tried a primitive version of immunotherapy against cancer more than 100 years ago. It sometimes worked remarkably well, but often did not, and they did not understand why. Eventually, radiation and chemotherapy eclipsed it. (Identification of a problem)
Researchers are now focused on two promising types of immunotherapy. One creates a new, individualized treatment for each patient by removing some of the person’s immune cells, altering them genetically to kill cancer and then infusing them back into the bloodstream. This treatment has produced long remissions in a few hundred children and adults with deadly forms of leukemia or lymphoma for whom standard treatments had failed.
The second approach, far more widely used and the one Mr. Cara tried, involves mass-produced drugs that do not have to be tailored to each patient. The drugs free immune cells to fight cancer by blocking a mechanism — called a checkpoint — that cancer uses to shut down the immune system. (Description of a solution)
These drugs, called checkpoint inhibitors, have been approved by the Food and Drug Administration to treat advanced melanoma, Hodgkin’s lymphoma and cancers of the lung, kidney and bladder. More drugs in this class are in the pipeline. Patients are clamoring for checkpoint drugs, including one, Keytruda, known to many as “that Jimmy Carter drug” which, combined with surgery and radiation, has left the former president with no sign of recurrence even though melanoma had spread to his liver and brain.
Yet for all the promise and excitement, the fact is that so far, immunotherapy has worked in only a minority of patients, and researchers are struggling to find out why. They know they have their hands on an extraordinarily powerful tool, but they cannot fully understand or control it yet. (Evaluation of the solution)
(http://www.nytimes.com/2016/07/31/health/harnessing-the-immune-system-to-fight-cancer.html?rref=collection%2Fseriescollection%2Fimmunotherapy)
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