Researchers transfer immune response to myeloma patient
Researchers at the University of Arkansas for Medical Sciences
(UAMS) have for the first time transferred an immune response in a
healthy individual to a patient with multiple myeloma, a cancer of the
bone marrow, showing promise for cancer vaccination.
In the study, conducted in the UAMS Myeloma Institute for Research
and Therapy, a healthy individual was immunized with a cancer protein
that can kick start the body's immune system to kill cancer cells. The
cancer-killing antibodies produced by the healthy patient's immune
system were then transferred via stem cell transplant to her twin
sister, who had been diagnosed with multiple myeloma, in conjunction
with chemotherapy.
The same immune response was subsequently observed in the patient,
who remains in remission nearly three years after the transplant. An
article on the study, "Immunization with a recombinant MAGE-A3 protein
after high-dose therapy for myeloma" was published in the
November/December 2007 issue of the Journal of Immunotherapy .
"Vaccination therapies have not yet been proven clinically effective
for myeloma, possibly due to disruptions in the patient's immune system
caused by chemotherapy or the disease itself," said Frits van Rhee,
M.D., Ph.D., leader of the research team and director of clinical
research in the Myeloma Institute. "The ability to define and transfer
an immune reaction from a healthy donor to a patient with multiple
myeloma may give us another tool with long-lasting protection against
disease recurrence."
Van Rhee, also a professor in the UAMS College of Medicine, said
that the donor and patient being identical twins provided an ideal
situation to test the vaccination. Because the stem cells came from an
identical twin, the researchers were able to avoid immunosuppressive
therapy that would normally be necessary and could have hampered the
immune response, he said.
The vaccine targeted a "cancer-testis" antigen known as MAGE-A3.
Cancer-testis antigens are a group of proteins which have been found to
be produced in cancerous cells but not in normal tissues. Cancer testis
antigen-targeted therapy will therefore only destroy the malignant
tissues which express them, making this type of therapy far less toxic
than non-specific chemotherapies, van Rhee said.
After receiving the stem cell transplant, the patient also was
vaccinated to boost the anti-myeloma response. The vaccines produced
strong antibody and cellular responses in both the donor and the
patient, said the researchers.
The MAGE-A3 vaccine used in this study is manufactured by
Glaxo-Smith-Kline, and is currently showing promise in Phase III trials
in small cell lung cancer, the researchers said.
They said the next step in the research is a larger-scale vaccination trial of myeloma patients, van Rhee said.