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
