oncolytic virus designed to seek out, attack and
destroy tumor cells. It is designed to reproduce
selectively in tumor cells that exhibit activity
via EGFR/Ras, but not in normal tissue. In this
study the authors conducted a clinical trial on
a group of patients all of whom had advanced
cancer affecting various organs and who did
not respond to conventional treatments. The
patients received a single injection of the genetically
modified JX-594 virus at different doses.
Analysis of the biopsies from the tumors showed
that in several patients the virus was able to
infect and multiply in tumor cells but not in
normal healthy tissue. Furthermore, expression
of the foreign gene that had been inserted into
the virus to aid its detection was also discovered
in the tumors. This virus was well tolerated by
the patients even at the highest doses as the only
side effect was a flu-like malaise, which lasted
only 1 day.
This is the first time that a viral therapy that
replicates exclusively in tumoral tissue after
intravenous injection has been successful in
humans. This strategy allows foreign genes to
be selectively expressed in tumor cells, which
opens up the possibility of selectively inserting
therapeutic substances into solid tumors
in humans. Although with this approach the
researchers did not manage to cure any of the
patients, they have shown that we are already
able to modify certain viruses, inject them into
patients, make the virus seek out only tumor
cells while ignoring all healthy cells and have
them inject the appropriate antidote. The
authors of this paper have produced the ‘magic
bullet’, which perhaps in the future we may tailor
to make it effective against different types
of cancer.
“This strategy allows foreign genes to be
selectively expressed in tumor cells,
which opens up the possibility of
selectively inserting therapeutic
substances into solid tumors in humans.”
Curing human diseases is a complex problem
that requires complex solutions. It is only
through coordinated and interdisciplinary work
that teams of microbiologists, molecular biologists,
computer biologists, engineers, chemists,
physicians and other professionals will be able
to provide new and original solutions. In recent
months we have seen examples of how the synthetic
manipulation of bacteria and viruses
allows the design of new strategies that offer