New cancer drugs could help in autoimmune disease

CHICAGO, Oct 7 (Reuters) A new class of drugs used to treat cancer might be effective at suppressing overactive immune systems in patients with autoimmune diseases like Crohn's disease, US researchers said today.

''What we would be proposing would be a therapy that would enhance the body's own immune system's ability to regulate itself,'' said Wayne Hancock of Children's Hospital of Philadelphia, whose study appears in the journal Nature Medicine.

Hancock said drugs known as histone deacetylases inhibitors, or HDACs, which affect compounds involved in the growth and death of cancer cells, bolstered the production of cells that regulate the immune system in mice.

In one study, the drug helped reverse and prevent inflammatory bowel disease. It also prevented the rejection of heart transplants in other mice. And it stopped rejection of pancreatic cell transplants in other mice.

These transplants are currently given to some type 1 diabetics, whose natural insulin-producing islet cells have been destroyed by the disease.

Islet-cell transplants often fail after a year. But Hancock thinks therapies using HDAC drugs might be able to prevent this.

''In most animals, if we gave them an HDAC inhibitor, we were able to enhance T-regulatory function and suppress rejection and induce ong-term graft survival,'' he said in a telephone interview.

While many companies are working on HDACs, Hancock's study focused on the Merck&Co Inc drug Zolinza, also known by its chemical name suberoylanilide hydroxamic acid, or SAHA.

Zolinza is approved in the United States to treat cutaneous T cell lymphoma, a type of skin cancer.

Hancock said SAHA appears to bolster the work of regulatory T-cells that suppress the immune system. ''Their job is to act as police and dampen down inflammatory responses,'' he said.

The study offers evidence that a drug could be used to enhance regulatory T-cell production and function. ''That hadn't been done before,'' Hancock said.

He and colleagues are working with researchers in Minnesota to try the Merck drug Zolinza in diabetic monkeys with islet cell transplants.

Hancock said the drugs have the potential to treat other autoimmune diseases, like rheumatoid arthritis.

So far, they are mostly being studied in cancer, but that could change.

''I image a number of companies who have been developing these compounds for oncology will pick up their ears when they hear this,'' he said.

REUTERS TB AS0037