By Holly Nott, Austrailian Associated Press
November 25, 2004
A laboratory mouse recovered fully from mesothelioma and built up immunity to further tumours during trials of a new treatment regime being tested by West Australian researchers.
Mesothelioma cells were transplanted into the animal, dubbed Mouse 5, before it was given a chemotherapy drug called coramsine, which is still in development, in combination with drugs to stimulate the immune system.
University of Western Australia researcher Richard Lake said Mouse 5 not only recovered from mesothelioma, which is presently regarded as incurable in humans, but rejected subsequent attempts to grow another tumour.
“The second part of the experiment . . . was when he was rechallenged,” Dr Lake said.
“We asked the question `if he was given a tumour again would he be able to recognise and reject that tumour’ and in fact that was found to be the case.
“So what we had done was produce a level of immunity in the animal which of course is very important ultimately if we’re thinking about clinical trials where we may be able to remove large parts of the tumour but the remnants of the tumour . . . still need to be treated.
“It may be that the immune system gives us the best access to those deposits of tumour which we find in distant sites.”
Dr Lake said the principle of combining chemotherapy and immunotherapy was a relatively new one but was providing “extremely promising” results that could be applied to other human cancers.
“This is a strategy which is designed to work with patients who have cancer,” Dr Lake said. “It is not a preventative strategy. It is not a vaccination strategy for people who are worried that they may get cancer.”
He said he hoped the treatment regime would progress to clinical trials on people next year.
“Combining the right sort of chemotherapy with the right sort of immunotherapy – this has been our strategy to try and understand how we might best develop useful combinations and therapies,” Dr Lake said.
Coramsine was developed by Perth-based company Solbec Pharmaceuticals using a noxious weed called Devil’s Apple.
In the trial, which is in its “very preliminary” stages, Mouse 5 was the only survivor, with two others dying of coramsine overdoses and two more put down after their tumours returned.