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| This Nov. 18, 2013 photo provided by the The Children's Hospital of Philadelphia shows Emily Whitehead, 8, 20 months after T Cell Therapy treatment in Philadelphia. In one of the biggest advances against leukemia and other blood cancers in many years, doctors are reporting unprecedented success by using gene therapy to transform patients' blood cells into soldiers that seek and destroy their cancer. |
In one of the biggest
advances against leukemia and other blood cancers in many years, doctors
are reporting unprecedented success by using gene therapy to transform
patients' blood cells into soldiers that seek and destroy cancer.
A
few patients with one type of leukemia were given this one-time,
experimental therapy several years ago and some remain cancer-free
today. Now, at least six research groups have treated more than 120
patients with many types of blood and bone marrow cancers, with stunning
results.
"It's really exciting," said Dr.
Janis Abkowitz, blood diseases chief at the University of Washington in
Seattle and president of the American Society of Hematology. "You can
take a cell that belongs to a patient and engineer it to be an attack
cell."
In one study, all five adults and 19 of
22 children with acute lymphocytic leukemia, or ALL, had a complete
remission, meaning no cancer could be found after treatment, although a
few have relapsed since then.
These were
gravely ill patients out of options. Some had tried multiple bone marrow
transplants and up to 10 types of chemotherapy or other treatments.
Cancer
was so advanced in 8-year-old Emily Whitehead of Philipsburg, Pa., that
doctors said her major organs would fail within days. She was the first
child given the gene therapy and shows no sign of cancer today, nearly
two years later.
Results on other patients
with myeloma, lymphoma and chronic lymphocytic leukemia, or CLL, will be
reported at the hematology group's conference that starts Saturday in
New Orleans.
Doctors say this has the
potential to become the first gene therapy approved in the United States
and the first for cancer worldwide. Only one gene therapy is approved
in Europe, for a rare metabolic disease.
The
treatment involves filtering patients' blood to remove millions of white
blood cells called T-cells, altering them in the lab to contain a gene
that targets cancer, and returning them to the patient in infusions over
three days.
"What we are giving essentially
is a living drug" - permanently altered cells that multiply in the body
into an army to fight the cancer, said Dr. David Porter, a University of
Pennsylvania scientist who led one study.
Several
drug and biotech companies are developing these therapies. Penn has
patented its method and licensed it to Switzerland-based Novartis AG.
The company is building a research center on the Penn campus in
Philadelphia and plans a clinical trial next year that could lead to
federal approval of the treatment as soon as 2016.
Talking
with the researchers, "there is a sense of making history ... a sense
of doing something very unique," said Hervé Hoppenot, president of
Novartis Oncology, the division leading the work.
Lee Greenberger, chief scientific officer of the Leukemia and Lymphoma Society, agreed.
"From
our vantage point, this looks like a major advance," he said. "We are
seeing powerful responses ... and time will tell how enduring these
remissions turn out to be."
The group has
given $15 million to various researchers testing this approach. Nearly
49,000 new cases of leukemia, 70,000 cases of non-Hodgkin lymphoma and
22,000 cases of myeloma are expected to be diagnosed in the United
States in 2013.
Many patients are successfully
treated with chemotherapy or bone marrow or stem cell transplants, but
transplants are risky and donors can't always be found. So far, gene
therapy has been tried on people who were in danger of dying because
other treatments failed.
The gene therapy must
be made individually for each patient, and lab costs now are about
$25,000, without a profit margin. That's still less than many drugs to
treat these diseases and far less than a transplant.
The
treatment can cause severe flu-like symptoms and other side effects,
but these have been reversible and temporary, doctors say.
Penn
doctors have treated the most cases so far - 59. Of the first 14
patients with CLL, four had complete remissions, four had partial ones
and the rest did not respond. However, some partial responders continue
to see their cancer shrink a year after treatment.
"That's
very unique to this kind of therapy" and gives hope the treatment may
still purge the cancer, said Porter. Another 18 CLL patients were
treated and half have responded so far.
Penn
doctors also treated 27 ALL patients. All five adults and 19 of the 22
children had complete remissions, an "extraordinarily high" success
rate, said Dr. Stephan Grupp at the Children's Hospital of Philadelphia.
Six have since relapsed, though, and doctors are pondering a second gene therapy attempt.
At
the National Cancer Institute, Dr. James Kochenderfer and others have
treated 11 patients with lymphoma and four with CLL, starting roughly
two years ago. Six had complete remissions, six had partial ones, one
has stable disease and it's too soon to tell for the rest.
Ten
other patients were given gene therapy to try to kill leukemia or
lymphoma remaining after bone marrow transplants. These patients got
infusions of gene-treated blood cells from their transplant donors
instead of using their own blood cells. One had a complete remission and
three others had significant reduction of their disease.
"They've
had every treatment known to man. To get any responses is really
encouraging," Kochenderfer said. The cancer institute is working with a
Los Angeles biotech firm, Kite Pharma Inc., on its gene therapy
approach.
Researchers at Memorial
Sloan-Kettering Cancer Center will report on 13 patients with ALL; the
University of Texas MD Anderson Cancer Center will report about
two-dozen patients with ALL or lymphoma, and Baylor College of Medicine
will give results on 10 patients with lymphoma or myeloma.
Patients are encouraged that relatively few have relapsed.
"We're
still nervous every day because they can't tell us what's going to
happen tomorrow," said Tom Whitehead, 8-year-old Emily's father.
Doug
Olson, 67, a scientist for a medical device maker, shows no sign of
cancer since gene therapy in September 2010 for CLL he had had since
1996.
"Within one month he was in complete remission. That was just completely unexpected," said Porter, his doctor at Penn.
Olson ran his first half-marathon in January and no longer worries about how long his remission will last.
"I decided I'm cured. I'm not going to let that hang over my head anymore," he said.
