Washington, May 16 (IANS) A 49-year-old US woman with
advanced bone marrow cancer called multiple myeloma is effectively
cancer-free after receiving an experimental trial that injected her a
single dose of an engineered measles vaccine, a study said.
The
patient, with tumors all over her body, including a three-cm-diametre
one on her forehead, experienced complete remission of myeloma and has
been clear of the disease for over six months, Xinhua reported citing
the study published in Mayo Clinic Proceedings.
A second patient,
a 65-year-old woman, did not respond as well to the virus treatment
that is selectively toxic to myeloma plasma cells, researchers said.
However,
high-tech imaging studies "provided a clear proof" that the
intravenously administered virus specifically targeted the sites of
tumor growth.
The researchers said the trial is a "proof of
concept" that virotherapy, destroying cancer with a virus that infects
and kills cancer cells but spares normal tissues, can be effective
against the deadly cancer multiple myeloma.
"This is the first
study to establish the feasibility of systemic oncolytic virotherapy for
disseminated cancer," Mayo Clinic hematologist Stephen Russell, first
author of the paper and co-developer of the therapy, said in a
statement.
"These patients were not responsive to other therapies and had experienced several recurrences of their disease."
Virotherapy
has a history dating back to the 1950s, according to the Mayo Clinic,
and thousands of cancer patients have been treated with a host of
various viruses.
"However, this study provides the first
well-documented case of a patient with disseminated cancer having a
complete remission at all disease sites after virus administration."
It was noted that both patients were studied at the highest possible dose of the therapy.
Both
women also had limited previous exposure to measles, and therefore
fewer antibodies to the virus, and essentially had no remaining
treatment options.
The researchers said their next step is to see
if the measles vaccine works in a larger number of patients. They also
want to test the effectiveness of the virotherapy in combination with
radioactive therapy in a future study.