University of Auckland researchers have high hopes for a new cancer treatment they've developed, which helps the body's immune system find and destroy cancerous cells.
The drug, currently known as SN38437, targets an enzyme produced by cancerous cells called IDO1.
"This enzyme causes a loss of a particular amino acid which is critically important for the development of T-cells, and T-cells are of course one of the first lines of defence against infections -- including cancer," says Professor Bill Denny, director of the Auckland Cancer Society Research Centre at the University of Auckland.
The amino acid in question is tryptophan, which the body can't produce on its own.
"In diminishing the amount of this nutrient for T-cells, you tend to weaken the body's immune system. Blocking this process should stimulate the body's immune system to be much better and effective at fighting cancer cells."
Researchers looked at more than 40,000 different chemical compounds, tweaking and improving the ones best at inhibiting the production of IDO1, with one compound -- SN38437 -- emerging as the most promising.
"A drug has to go through many levels of development, and it has to be successful at all of those," says Prof Denny.
Traditional treatments such as chemotherapy focus on attacking cancerous cells directly, but can be indiscriminate -- also taking out healthy cells.
"This is an example of a whole new class of ways of treating cancer, by trying to improve the body's immune system to help fight the disease itself. Although this is still at a relatively early stage, it's one of a whole new way of treating tumours."
It's hoped human trials will begin soon, but even after "seven or eight years" of research, it could be another half-a-decade before its effectiveness and safety are confirmed.
IDO1 is produced by a wide range of cancers, including cancers of the pancreas, cervix, breast, lung, prostate, colon, ovaries and blood.
There are two other similar drugs which inhibit IDO1 in trials overseas, but Prof Denny says SN38437 has more potential.
"Technologies reach a certain level all over the world at the same time, and this is still a very new process… There are certainly other groups working on it, but we are certainly well out in the front."