Mon Dec 9, 4:24 PM ET
By Maggie Fox, Health and Science Correspondent
A new treatment using drugs and ultraviolet light helps bone marrow transplants work better in cancer patients, U.S. researchers reported on Monday.
More than 4,500 patients in the United States get bone marrow transplants
every year. The idea is to replace faulty immune cells, which are produced
in the bone marrow, with healthy ones.
The new approach, which uses an existing cancer drug and a light treatment
called phosphophoresis, helps patients tolerate bone marrow transplants
from donors without developing a life-threatening complication called graft-versus-host
disease, researchers said at an annual meeting of the American Society
of Hematology in Philadelphia.
It also helps the transplants "take" better, greatly increasing the
effectiveness against the patients' cancers, said Dr. Francine Foss, director
of the lymphoma program at Tufts New England Medical Center in Boston.
The new regime could greatly help older cancer patients, especially
those with leukemia and other blood-related cancers, Foss said.
"We have combined two treatments -- one pentostatin, which is a drug
that affects T-cells. It is an immune suppressing drug," Foss said in a
"We have combined it with a treatment called phosphophoresis, which
involves exposing white blood cells to ultraviolet light."
Both treatments change the nature of immune cells called T-cells. Instead
of orchestrating an immune system attack on the donor cells, the patient's
body seems to tolerate them.
The drug, sold by Dublin, California-based SuperGen Inc. under the brand-name Nipent, is now marketed for a disease known as hairy cell leukemia.
Foss and colleagues gave Nipent and the light treatment to 90 patients with advanced cancers such as leukemia, lymphoma and multiple myeloma.
They followed the patients for an average of 18 months, with some having survived three years.
REDUCTION IN SIDE EFFECTS
"The incidence of graft-versus-host disease is about 10 percent, and chronic graft-versus-host disease is about the same," Foss said.
This compares to a rate of between 40 percent and 50 percent with current transplant regimens. The patients also had relatively few side-effects and most could eat normally.
More than 80 percent of the patients had successful engraftment, meaning the donated bone marrow took up residence and started working and 85 percent were alive after a year, Foss reported.
This was remarkable, she said, as only the very sickest patients took part in the Phase II trial.
"Overall survival was about 65 percent," she said. Typically, the expected survival rate would be 40 percent. The patients were all either old or had conditions that normally would not allow them to have bone marrow transplants.
"The outcome is usually dismal for these patients," Foss said, adding that most leukemia patients are older than 65 and have more trouble surviving it.
"This is primarily a disease of the elderly," she said. "There is much more press when kids get leukemia, but in actuality most leukemia in the United States occurs in people over 50."
Bone marrow transplants are mostly used to treat cancer, but doctors are using transplants to fight other blood- and immune-system diseases such as sickle cell anemia or multiple sclerosis.
Next, the researchers plan to do trials to show whether it is the drug
that is working, the light treatment, or whether it takes the combination
to be effective.
Copyright © 2002 Reuters Limited