Drug that kills cancer may have other uses

The drug is a synthetic version of a chemical produced in sheep that eat red clover. Photo / Greg Bowker

A drug originally synthesised from a compound found in sheep that eat red clover can not only kill cancer cells, but may be useful against immune-system diseases, New Zealand researchers say.

The Wellington-based Malaghan Institute has shown phenoxodiol may be effective in tackling some diseases where a patient is being attacked by their own immune system.

The drug was successfully used on abnormally proliferating forms of the immune system's killer T-cells, and on other rapidly dividing cancer cells such as primary myeloid and lymphoid leukaemic blast cells.

The problem cells undergo a "programmed" cell death when exposed briefly to the anti-tumour drug, said Professor Alan Husband, of drug company Marshall Edwards, which commissioned the research.

The company is developing phenoxodiol as a sensitising agent to be used with platinum drugs for late-stage, chemoresistant ovarian cancer, and as a treatment by itself for prostate and cervical cancers.

Standard chemotherapy drugs often have a limited duration of use against late-stage ovarian cancers which progressively lose sensitivity to chemotherapy - but phenoxodiol may be able to restore drug sensitivity to the resistant cancer cells.

Two years ago, Malaghan Institute researcher Michael Berridge showed that phenoxodiol not only successfully targets cancer proteins, inducing the cancerous cells to die, but can also enhance chemotherapy by breaking down resistance to the treatment.

Laboratory studies have shown the cancer cells pre-treated with phenoxodiol were killed with lower doses of chemotherapy drugs - but the phenoxodiol did not hurt normal cells.

The company has been given fast-track status by the United States' Food and Drug Administration to develop the compound as a therapy for recurrent ovarian and prostate cancers.

Marshall Edwards said yesterday that Malaghan Institute research published last month in the Haematologica journal showed phenoxodiol might also be useful against autoimmune diseases, such as rheumatoid arthritis and psoriasis, and in management of graft rejection in transplant patients.

The drug is a synthetic version of a chemical produced in sheep that eat red clover converting plant hormones to compounds with significant anti-cancer properties in humans.

- NZPA