Wednesday, December 07, 2016

This cancer therapy is turning body against itself

Immunotherapy Drugs Causing New Type Of Acute-Onset Diabetes, Can Attack Healthy, Vital Organs
As Chuck Peal lay in a US emergency room one Sun day in early September, doctors furiously tried to make sense of his symptoms. Peal, 61, slipped in and out of consciousness, his blood pressure plummeted, his potassium levels soared and his blood sugar spiked to 10 times the normal level. A doctor suspected a heart attack, but it wasn't. Peal's body was attacking itself, a severe reaction by his immune system that was a side-effect of a seemingly miraculous cancer treatment.
In the seven weeks prior, doctors at Yale had combated Peal's melanoma with two of the most promising drugs in cancer treatment today . These medicines work by stimulating the immune system to attack cancer as ferociously as it does other threats, like viruses and bacteria.
These so-called immunothe rapy drugs have been hailed as a breakthrough in cancer treatment, attracting billions of research dollars. But as their use grows, doctors are finding that they pose serious risks that stem from the very thing that makes them effective. An unleashed immune system can attack healthy , vital organs: notably the bowel, the liver and the lungs, but also the kidneys, the adrenal and pituitary glands, and, in rare cases, the heart.Doctors at Yale believe immunotherapy is causing a new type of acute-onset diabetes, with at least 17 cases so far, Peal's among them. Studies are finding that severe reactions occur nearly 20% of the time with certain drugs, and in more than half of the patients when some drugs are used in combination.
Another recent paper found that 30% of patients experienced “interesting, rare or unexpected side effects“, with a quarter of the reactions described as severe, life-threatening or requiring hospitalisation. Some patients have died.
The upshot, oncologists and immunologists say , is that the medical field must be more vigilant as these drugs soar in popularity . And they say more research is needed into who is likely to have reactions and how to treat them. “We are playing with fire,“ said Dr John Timmerman, an oncologist and immunothera py researcher at the University of California, Los Angeles, who recently lost a patient to side-effects. The woman's immunotherapy drugs had successfully “melted away“ her cancer, he said, but some weeks later, she got cold and flulike symptoms and died from an inflammatory response that Timmerman described as “a mass riot, an uprising“ of her immune system.
Despite the warnings, physicians remain hugely supportive of drugs that are saving people who would otherwise die. Far better to cope with diabetes or hepatitis, the thinking goes, than die. Most reactions are treatable. “It's the nature of the beast,“ said Martin Bachmann, a professor and immunologist at the Jenner Institute, affiliated with Oxford University . “I'm not sure you can get rid of the side-effects -it's really what you want.“ Chemotherapy , too, has side-effects, but Yale oncologist Dr Harriet Kluger prefers immunotherapy's trade-offs because the drugs may offer enduring control of cancer without continued treatment.

With much momentum pushing for a cure, oncologists' focus is on more vigilance about the side-effects. Timmerman said he wished he had seen the signs of trouble in his patient. “If we'd only known the power we had unleashed...we might have saved her,“ he said.

Source: Times of India-5th December-2016
http://epaperbeta.timesofindia.com/index.aspx?EID=31804&dt=20161205