In one of the biggest
advances against leukaemia 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 leukaemia 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.
exciting," said Dr Janis Abkowitz, blood diseases chief at the University
of Washington in Seattle and president of the American Society of Haematology.
"You can take a cell that belongs to a patient and engineer it to be an
No sign of cancer
In one study, all five
adults and 19 of 22 children with acute lymphocytic leukaemia, 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, Pennsylvania, 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 leukaemia, or CLL, will be
reported at the haematology group's conference that starts Saturday in New
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.
A living drug
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 centre 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 Leukaemia 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."
Testing the approach
The group has given $15
million to various researchers testing this approach. Nearly 49 000 new cases
of leukaemia, 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 had 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
"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 leukaemia 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 Centre will report on 13 patients with ALL; the
University of Texas MD Anderson Cancer Centre will report on about two-dozen
patients with ALL or lymphoma, and Baylor University will give results on 10
patients with lymphoma or myeloma.
"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
"I decided I'm cured.
I'm not going to let that hang over my head anymore," he said.