I meant to jump on this sooner
but here we are. This is a very
important proof of concept in which a virus is used to produce hunter killer t
cells to destroy the cancer ruthlessly.
It was always thought possible, but success has obviously elusive. Now we have it actually working.
A working protocol can lead
surely to similar protocols for possibly all cancers. We should see a flood of applications to test
every cancer out there.
As I have posted before, several
other protocols are now out there so that cancer is generally well on the way
to been a solved problem. One protocol
in particular has my interest because it does not rely on the usual methods but
on inserting a nanoparticle directly into a cancer cell.
Yet this approach also is as good
now that it has been shown to work. I particularly
like the ability to lie doggo in case another attack starts up.
'Huge' results raise hope for cancer breakthrough
In early results from a clinical trial, genetically engineered T cells
eradicate leukemia cells and thrive. Two of three patients studied have been
cancer-free for more than a year.
A microscopic image shows two T cells binding to beads, depicted in
yellow, that cause the cells to divide. After the beads are removed, the T
cells are infused into cancer patients. (Dr. Carl June / Penn Medicine)
By Eryn Brown, Los Angeles
August 11, 2011
In a potential breakthrough in cancer research, scientists at the University of Pennsylvania have
genetically engineered patients' T cells — a type of white blood cell — to attack cancer cells in advanced cases of a
common type of leukemia.
Two of the three patients who received doses of the designer T cells in
a clinical trial have remained cancer-free for more than a year, the
researchers said.
Experts not connected with the trial said the feat was important
because it suggested that T cells could be tweaked to kill a range of cancers,
including ones of the blood, breast and colon.
"This is a huge accomplishment — huge," said Dr. Lee M.
Nadler, dean for clinical and translational research at Harvard Medical School, who discovered the
molecule on cancer cells that the Pennsylvania
Findings of the trial were reported Wednesday in two journals.
To build the cancer-attacking cells, the researchers modified a virus to carry instructions for
making a molecule that binds with leukemia cells and directs T cells to kill
them. Then they drew blood from three patients who suffered from chronic
lymphocytic leukemia and infected their T cells with the virus.
When they infused the blood back into the patients, the engineered T
cells successfully eradicated cancer cells, multiplied to more than 1,000 times
in number and survived for months. They even produced dormant
"memory" T cells that might spring back to life if the cancer was to
return.
On average, the team calculated, each engineered T cell eradicated at
least 1,000 cancer cells.
Side effects included loss of normal B cells, another type of white
blood cell, which are also attacked by the modified T cells, and tumor lysis
syndrome, a complication caused by the breakdown of cancer cells.
"We knew [the therapy] could be very potent," said Dr. David
Porter, director of the blood and marrow transplantation program at the
Hospital of the University of Pennsylvania in Philadelphia and a
coauthor of both papers, which were published in the New England Journal of
Medicine and Science Translational Medicine. "But I don't think we
expected it to be this dramatic on this go-around."
Bone marrow transplants from healthy donors have been effective in
fighting some cancers, including chronic lymphocytic leukemia, but the
treatment can cause side effects such as infections, liver and lung damage,
even death. One-fifth of bone marrow transplant recipients may die of
complications unrelated to their cancer, Porter said.
And so researchers have been working for many years to develop cancer
treatments that leverage a patient's immune system to kill tumors with much greater precision. "It is kind of a
holy grail," said Dr. Gary Schiller, a researcher with UCLA's Jonsson Comprehensive
Cancer Center
Earlier efforts to replace risky bone marrow transplants with such
engineered T cells proved disappointing because the cells were unable to
multiply or survive in patients, Porter said. This time, he said, the T
cells were more robust because the team added extra instructions to their virus
to help the T cells multiply, survive and attack more aggressively.
About 15,000 patients are diagnosed with chronic lymphocytic leukemia
every year, Porter said. Many can live with the disease for years. Bone marrow
transplants are the only treatment that eradicates the cancer.
Porter cautioned that these were preliminary results. The scientists
plan to continue the trial, treating more patients and following them over
longer periods. The researchers also would like to expand the work to other
tumor types and diseases, Porter said.
The hope, scientists said, is that the method would work for cancers
that can kill more ruthlessly and rapidly.
"It would be great if this could be applied to acute leukemia,
where there is a terrible unmet medical need," UCLA's Schiller said.
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