Australian Asbestos Diseases Research Institute (ADRI) has announced a
clinical trial for a newly developed drug therapy in the treatment of mesothelioma. Researchers
at the ADRI conducted a three year study focused on the genetic characteristics
and the gene expression and found that a particular family of microRNAs
was greatly decreased in mesothelioma.
MicroRNAs are small genes involved in the regulation of cell and tumor
biology, inhibition of this particular type of microRNAs is commonly found
in other types of cancers but has never been linked to mesothelioma.
Researchers treated human derived mesothelioma tumors in mice with a synthetic
version of microRNA, the drug TargomiRs, in an attempt to bring the microRNA
levels back up to normal. The drug was administered by way of minicells,
a new drug delivery system developed by biotech company EnGenIC, which
uses antibodies to guide the drug to the tumor site. The results were
remarkable. Not only was tumor growth inhibited, but surrounding healthy
tissue was unaffected.
ADRI hopes to begin a two phase clinical trial beginning at the end of
this year. The first phase will take about a year to complete and will
focus on the distribution of TargomiRs in a small number of patients.
The second phase will determine the optimal and safe dose of the experimental therapy.
The study will target patients who express specific types of epidermal
growth factor receptor (EGFR) gene mutations, the biomarker researchers
plan to use for the antibody-directed TargomiR delivery. In fact, the
FDA recently approved a new
drug in the treatment of certain types of lung cancer that express EGFR, which
could possibly be a viable treatment for mesothelioma patients.
Treatment options for this asbestos-related cancer are very limited and effective new therapies
are urgently needed." says Professor van Zandwijk, Director of the
Asbestos Diseases Research Institute. "I think the whole concept
is sound and we feel very reassured. While our preclinical research was
confined to mesothelioma, we hope that this new approach to cancer treatment
will also inhibit other tumor types."
This research was possible thanks to a donation of $1.2 million dollars
from the family of Andrew Lloyd, an Australian man who passed away in
August of 2011 from
malignant mesothelioma. Further funding is necessary to continue research over the next 2-3 years
to determine if the TargomiRs therapy will be a viable treatment option.
The ADRI was established by the Asbestos Diseases Research Foundation,
a charitable, not-for-profit foundation which aims to improve the prevention, the
diagnosis and treatment of asbestos-related diseases and to provide a better future
for all those Australians unfortunately exposed to asbestos.