Human Testing Starts of Engineered Anti-Cancer Drug Carrier
The first phase of clinical testing has begun of a heat-triggered,
sub-microscopic drug carrier invented by Professor David Needham of
the Pratt Department of Mechanical Engineering and Materials Science
and developed in collaboration with Dr. Mark Dewhirst in the Department
of Radiation Oncology.
The drug carriers are liposomes that are engineered to release the
agents they carry at the cancer site when tumor temperatures are raised
to 41 degrees Celsius. The clinical trial just getting underway is using the
special liposomes to carry the anticancer drug doxorubicin as a possible
prostate cancer treatment.
The clinical testing is being conducted at the Roswell Park Memorial
Institute in Buffalo, N.Y. under the auspices of the licensor of the
technology, Celsion Corp., of Columbia, Md. Celsion makes microwave
devices that deliver the heat for medical treatment.
The Phase 1 trial will be looking at the safety and maximum dosage of the
formulation. Dewhirst, director of the Duke Hyperthermia Program, said
the initial human tests are only beginning of a long road of clinical trials
before the therapy is approved for general use.
The liposomes are artificially engineered waxy capsules just two
molecules thick composed of lipids, materials similar to those that
surround every cell in the body. The liposomes are small enough to travel
through the bloodstream to deliver drugs to designated targets.
These liposomes can quickly dump their cargo because their special
membrane chemistry causes parts of their molecular structures to begin
"melting" when heat increases to the critical temperature. "It's like a
soccer ball with stitches," Needham said. "When its stitches
become leaky, the drug that is trapped inside will come out rapidly.
Such rapid release from the drug carrier is what is needed in order to kill the tumors."