Drug combo might beat type 1 diabetes

Apr 23 2006

Scientists in California have developed a cocktail of drugs which can reverse diabetes and say the discovery is an important step towards a potential cure.

That may mean a potential end to the daily routine of insulin injections and rigid dietary restrictions suffered by millions throughout the world.

The cocktail of the two drugs, the anti-CD3 antibody and proinsulin peptide has to date only been tested on animals but each of its constituents is already being tested individually in human clinical trials.

The monoclonal antibody apparently calms the immune system while the peptide acts like a vaccine in providing protection for the insulin-producing cells.

The treatment is designed for Type 1 diabetes, which usually starts in childhood and occurs when the immune system turns on itself and attacks the insulin-producing cells of the pancreas.

The cocktail of drugs was developed by scientists at La Jolla Institute for Allergy and Immunology in San Diego; it was found in mice to be more effective, longer-lasting and had fewer side effects than either therapy had shown alone in the human studies.

In most of the mice tested, the diabetes was reversed.

Previous trials of the monoclonal antibody in humans have already shown it can reverse Type 1 diabetes but although the effect lasted for more than a year, the diabetes ultimately returned.

These results suggest that when combined with the peptide, the two drugs act together to produce a greater effect than either individually.

Experts in the field have welcomed the findings and the research team says it hopes to begin human trials of the combination therapy later this year but is presently waiting for approval from drugs safety regulators.

The treatment involves the antibody being given orally and the peptide by nasal spray, which avoids the need for injections.

The researchers say the novel approach focuses on teaching the immune system to tolerate, rather than attack, the insulin-producing cells of the pancreas.

The danger of suppressing the immune system is that it puts patients at increased risk of cancers or viral infections and by combining drugs, a lower dose of the immuno-suppressant antibody is required, with a lower risk of side effects.

The team was led by Matthias von Herrath, M.D., an internationally recognized expert on the molecular basis of type 1 diabetes who says it is the first time a vaccine strategy has been tried in Type 1 diabetes.

Diabetics inject insulin to control their blood-sugar levels but complete control is difficult to achieve.

Complications can lead to kidney failure, blindness and amputations.

Dr. von Herrath says since the complications from high blood sugar levels (diabetes) worsen with time, he is hopeful that the therapy can reverse the disease in patients before they have too much multi-organ damage.

The finding is published in the online version of the Journal of Clinical Investigation.