2018 Nobel prize in Medicine Awarded to 2 Cancer Immunotherapy Researchers
The Nobel prize in Physiology or Medicine was awarded on
Monday to James P. Allison of
us and Tasuku Honjo of Japan for his or her work on
unleashing the body’s
immune system to attack cancer, a breakthrough that has led
to a completely new class of
drugs and brought lasting remissions to several patients who
had run out of options.
Their success, which came after many researchers had given
upon the idea, “brought
immunotherapy out from decades of skepticism,” said Dr. Jedd
Wolchok, a cancer
a specialist at Memorial Sloan Kettering Cancer Center in NYC.
It has, he said, “led to
human applications that have affected an untold number of
people’s health.”
Before Dr. Allison’s and Dr. Honjo’s discoveries, cancer
treatment consisted of surgery,
radiation, chemotherapy, and hormonal treatments. A
statement from the Nobel
committee hailed their accomplishments as establishing “an entirely new principle for
cancer therapy.”
The drugs supported their work belong to a category called
checkpoint inhibitors, with
tongue-twisting names that have nonetheless become familiar
to several patients. The first
ones approved were ipilimumab (brand name Yervoy), nivolumab
(Opdivo) and
pembrolizumab (Keytruda). Others have since come to the
market.
Earlier attempts by other researchers to recruit the immune
system to fight cancer
sometimes worked but more often did not. Dr. Allison and Dr.
Honjo succeeded where
others had failed by deciphering exactly how cells were
interacting so they could finetune
methods to control the immune system.
Checkpoint inhibitors do not work for everyone and they have
only been approved for
some cancers. They can have severe side effects, and they
are expensive, costing more
than $100,000 a year. But the approach, known as
immunotherapy has become a
the mainstay of treatment for a number of types of cancer and a great deal of research is
underway — including work by Dr. Allison and Dr. Honjo — to
find the best ways of
combining checkpoint inhibitors with one another and with
standard treatments to help
more patients.
The checkpoint inhibitors now on the market are used for
cancers of the lung, kidney,
the bladder, head, and neck; for the aggressive skin cancer
melanoma; and for Hodgkin
lymphoma and other cancers.
DEACTIVATED
T-CELL
1/11
ACTIVATED
T-CELL
ACTIVATED
T-CELL
Checkpoint
inhibitors
T-CELL
Immune
checkpoint
Antigen
Co-stimulator
CANCER
CELL
CANCER
CELL
ANTIGEN
PRESENTING
CELL
Antigen
receptor
T-CELLS
T-cells are a kind of white blood corpuscle which will
identify and kill infected, damaged or
cancerous cells. Each T-cell has clawlike receptors on its the surface which will recognize and
lock onto antigens, foreign or abnormal protein fragments on
the surface of infected or
cancerous cells.
ACTIVATING A T-CELL
The T-cell must be activated before it can find and attack
cancer cells. A specialized cell
presents the T-cell with an antigen from a neoplastic cell,
alongside a co-stimulator
2/11
protein. The T-cell begins to seek out and kill any cells
that are covered with an equivalent
antigen.
CANCER AND CHECKPOINTS
Cancer cells can avoid destruction by taking advantage of a
turn on the T-cell called an
immune checkpoint. The checkpoint can pack up the T-cell and
suppress the
immune response, allowing cancer to grow undisturbed.
CHECKPOINT INHIBITORS
Drugs referred to as checkpoint inhibitors can physically
block the checkpoint, which frees
the immune system to attack cancer. A single T-cell can kill
thousands of cancer cells.
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