An experimental vaccine has prevented and reversed type 1 diabetes in laboratory animals, researchers at Children's Hospital of Pittsburgh reported Wednesday.
The vaccine has not been tested in humans, but researchers hope to begin clinical trials late next year.
"We shouldn't jump the gun and think it's going to work in humans," said Nick Giannoukakis, one of the researchers and an associate professor of pathology and immunology at the University of Pittsburgh School of Medicine. "But there is certainly a lot of optimism."
The enthusiasm extends to a network of researchers throughout the country called the Type 1 Diabetes TrialNet Study Group, which is funded by the National Institutes of Health.
The network, which is conducting diabetes studies at more than 150 medical centers, has approved the approach in principle, pending completion of initial safety studies and approval from the U.S. Food and Drug Administration.
"This is a very promising approach," said Dr. Jay Skyler, TrialNet's chairman and associate director of the Diabetes Research Institute at the University of Miami Miller School of Medicine.
Dr. Massimo Trucco, the project's lead researcher, said he hopes drugmaker Baxter Healthcare Corp. will win FDA approval within three months.
The vaccine builds upon an earlier version, also developed at Children's, now being tested in humans.
That vaccine, however, has a highly complicated delivery mechanism that patients find unappealing. It requires people to be hooked to an IV line for several hours as they undergo a procedure called leukapheresis, in which white blood cells are removed from the body.
"The thing patients lament is the two to three hours they have to sit on a chair for this procedure," said Trucco, director of immunogenetics at Children's Hospital and professor of pediatrics at the University of Pittsburgh.
The new vaccine simply could be injected under the skin, like most other vaccines.
It relies on a delivery mechanism known as microspheres -- microscopic hollow beads that are 10 times smaller than a cell. Microspheres have been used to deliver other drugs. In this case, they are filled with targeted nucleic acid molecules made in the laboratory that can stop the body from destroying the cells that produce insulin.
In type 1 diabetes, T cells from the immune system travel to the pancreas and destroy insulin-producing beta cells. Insulin is a naturally occurring hormone that regulates the body's use of sugar.
In the recent experiments, researchers injected the microspheres near the pancreases of mice with autoimmune diabetes. The microspheres were captured by white blood cells -- known as dendritic cells -- which are then reprogrammed to block the immune system from attacking the insulin-producing cells.
Results of the study are published in the June issue of Diabetes, the journal of the American Diabetes Association.
Safety tests of an earlier vaccine could be completed by year's end, Giannoukakis said. Six patients are enrolled, out of 15 projected participants. Initial results, though not yet published, are encouraging, he said.
"There was a fear that we may have side effects," Giannoukakis said. "But we've seen no rashes, no fevers, no skin discoloration, no aches and pains."
Larger text
Smaller text
Print this article
E-mail this article
