New treatment attacks cancer cells
STORY HIGHLIGHTS
- Nick Wilkins was out of options for battling leukemia
- He is now cancer free after an experimental treatment
- Doctors taught Nick's immune cells to become adept at killing cancer
- Experts hope the treatment will quickly become more widely available
John Wilkins explained to
Nick, who was by then 14, that doctors had tried chemotherapy,
radiation, even a bone marrow transplant from his sister.
"I explained to him that we're running out of options," Wilkins remembers telling his son.
There was one possible treatment they could try: an experimental therapy at the University of Pennsylvania.
He asked his son if he understood what it would mean if this treatment didn't work.
"He understood he could die," Wilkins says. "He was very stoic."
A few months later, Nick traveled from his home in Virginia to Philadelphia to become a part of the experiment.
This new therapy was
decidedly different from the treatments he'd received before: Instead of
attacking his cancer with poisons like chemotherapy and radiation, the
Philadelphia doctors taught Nick's own immune cells to become more adept
at killing the cancer.
Two months later, he
emerged cancer-free. It's been six months since Nick, now 15, received
the personalized cell therapy, and doctors still can find no trace of
leukemia in his system.
Twenty-one other young
people received the same treatment at The Children's Hospital of
Philadelphia, and 18 of them, like Nick, went into complete remission --
one of them has been disease-free for 20 months. The Penn doctors
released their findings this weekend at the annual meeting of the
American Society of Hematology.
"It gives us hope that this is a cure," Nick's father says. "They're really close. I think they're really onto something."
'A whole new realm of medicine '
At the conference, two
other cancer centers -- Memorial Sloan-Kettering in New York and the
National Cancer Institute -- will be announcing results with
immunotherapies like the one Nick received. The results are promising,
especially considering that the patients had no success with practically
every other therapy.
"This is absolutely one
of the more exciting advances I've seen in cancer therapy in the last 20
years," said Dr. David Porter, a hematologist and oncologist at Penn.
"We've entered into a whole new realm of medicine."
In the therapy, doctors
first remove the patient's T-cells, which play a crucial role in the
immune system. They then reprogram the cells by transferring in new
genes. Once infused back into the body, each modified cell multiplies to
10,000 cells. These "hunter" cells then track down and kill the cancer
in a patient's body.
Essentially, researchers
are trying to train Nick's body to fight off cancer in much the same
way our bodies fight off the common cold.
In addition to the
pediatric patients, Penn scientists tried the therapy out in 37 adults
with leukemia, and 12 went into complete remission. Eight more patients
went into partial remission and saw some improvements in their disease.
The treatment does make
patients have flulike symptoms for a short period of time -- Nick got so
sick he ended up in the intensive care unit for a day -- but patients
are spared some of the more severe and long-lasting side effects of
extensive chemotherapy.
Penn will now work with
other medical centers to test the therapy in more patients, and they
plan to try the therapy out in other types of blood cancers and later in
solid tumors.
A university press
release says it has a licensing relationship with the pharmaceutical
company Novartis and "received significant financial benefit" from the
trial, and Porter and other inventors of the technology "have benefited
financially and/or may benefit financially in the future."
Searching for one-in-a-million cancer cells
The big question is whether Nick's leukemia will come back.
Doctors are cautiously
optimistic. The studies have only been going on since 2010, but so far
relapse rates have been relatively low: of the 18 other pediatric
patients who went into complete remission, only five have relapsed and
of the 12 adults who went into complete remission, only one relapsed.
Some of the adult patients have been cancer-free and without a relapse
for more than three years and counting.
Relapses after this
personalized cell therapy may be more promising than relapses after
chemotherapy or a bone marrow transplant, Porter explained.
First, doctors have been
delighted to find the reengineered T-cells -- the ones that know how to
hunt down and attack cancer -- are still alive in the patients' bodies
after more than three years.
"The genetically
modified T-cells have survived," Porter said. "They're still present and
functional and have the ability to protect against recurrence."
Second, before declaring patients in remission, Penn doctors scoured especially hard for errant leukemia cells.
Traditionally, for the
kind of leukemia Nick has, doctors can find one in 1,000 to one in
10,000 cancer cells. But Penn's technology could find one in 100,000 to
one in a million cancer cells, and didn't find any in Nick or any of the
patients who went into complete remission.
'It's not a fluke'
One of the best aspects
of this new treatment is that it won't be terribly difficult to
reproduce at other medical centers, Porter said, and one day, instead of
being used only experimentally, it could be available to anyone who
needed it.
"Our hope is that this
can progress really quite quickly," he said. "It won't be available to
everyone next year, but I don't think it would take a decade, either."
Right now patients can
only get this therapy if they're in a study, but Dr. Renier Brentjens,
director for cellular therapeutics at Memorial Sloan-Kettering, says he
thinks it could become available to all patients in just three to five
years.
"When you have three
centers all with a substantial number of patients seeing the same thing
-- that these cells work in this disease - you know it's not a fluke,"
he said.
Two days ago, Brentjens
became the co-founder of Juno Therapeutics, a for-profit biotech
start-up company that's working on immunotherapies.
"Fifteen years ago I was
in the lab looking at these cells kill tumor cells in a petri dish and
then I saw them kill tumor cells in mice, and then finally in humans,"
Brentjens said.
He says he'll never
forget the first patient he treated, who initially had an enormous
amount of cancer cells in his bone marrow. Then after the therapy,
Brentjens looked under the microscope and, in awe, realized he couldn't
find a single cancer cell.
"I can't describe what that's like," he said. "It's fantastic."
CNN
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