For the first time, scientists have found a drug that can delay the onset of type 1 diabetes in those who are at high risk of developing the autoimmune disease, a finding some experts are calling a milestone in type 1 diabetes research.

In high-risk people, 14 days of therapy with the experimental drug teplizumab delayed development of the disease by a year or more, according to results from a study presented Sunday at an American Diabetes Association meeting in San Francisco. The results of the study were simultaneously published in the New England Journal of Medicine.

The phase 2 trial, which studies a drug's effectiveness in a relatively small number of people, is the first to show that immunotherapy can be used to delay the onset of an inherited disease.

“This is a huge milestone. We’ve had trials that have been going on for a couple decades, but they have not been able to prevent diabetes. It was a very disappointing result in the field,” said lead study author Dr. Kevan Herold, professor of immunology and endocrinology at Yale University. “This is the first successful trial to show that you can delay and possibly prevent, type 1 diabetes.”

The 76 study participants, who ranged in age from 8 to 49, faced a high risk of type 1 diabetes in part because their relatives had the disease, which kills the beta cells in the pancreas that make and release insulin. Also, the volunteers all had tests showing diabetes-related autoantibodies that attack the pancreas, plus unhealthy blood sugar levels.

Among the 44 volunteers randomly assigned to receive the drug, 19, or 43 percent, developed diabetes, with the disease appearing within 48.4 months in half of them.

By comparison, among the 32 people who received a placebo, 23, or 72 percent, developed diabetes, with half the patients developing it within 24.4 months.

When the study was stopped, the percentage of diabetes-free participants was twice as high in the teplizumab group, 57 percent, as in the placebo group, 28 percent.

The chief side effects were temporarily low levels of lymphocytes — a type of white blood cell — and a rash.

“Not having diabetes is a big deal. Anything that can prevent the disease will bring huge excitement,” Herold said. “We are anxious to hear from the FDA what the regulatory path is moving forward.”

The long awaited results have re-energized the diabetes research community.

Dr. Clifford Rosen of the Maine Medical Center Research Institute and Journal deputy editor Dr. Julie Ingelfinger wrote in an editorial, “We can finally say that there has been substantial progress in modulating the early course of type 1 diabetes.”

And Dr. Fernando Ovalle, director of the division of endocrinology, diabetes and metabolism at the University of Alabama at Birmingham, who was not involved in the study, noted that while this approach is unlikely to fully prevent or reverse type 1 diabetes, it may be used in combination with other approaches that may some day lead to a cure.

“I would argue that drugs like Verapamil, which have been shown to preserve beta cell function in adults with newly diagnosed type 1 diabetes, can play a significant synergistic role in combination with these immune modulator therapies, and deserves further study,” Ovalle said.

About 1.25 million people in the U.S. have type 1 diabetes, with nearly 18,000 new cases diagnosed annually in people under age 20, the American Diabetes Association says. The life expectancy of a type 1 diabetic is a decade shorter than those without the disease.

Currently, the treatments for type 1 diabetes include:

Taking insulin via injection, an insulin pump, or artificial pancreas

Carbohydrate, fat and protein counting

Frequent blood sugar monitoring

Eating healthy foods, and

Exercising regularly and maintaining a healthy weight

The promise is that teplizumab, which works by modifying the white blood cells from the immune system that kill insulin-producing cells in the pancreas, would delay or even prevent the disease in children who are at high risk so they do not have to make these life altering changes.

“We’re talking about not having diabetes. This might be the difference between getting the disease at 8 or 12 or even after high school, so these results have significant importance,” Herold told NBC News.

“This is the first immune modulator that has been shown to change the progression of the disease. This may open a whole new area of investigation on how to use immunotherapy to treat other autoimmune diseases,” he added.

The drug’s greatest impact seemed to be in the first year after treatment, when only 7 percent developed type 1 diabetes, compared with 44 percent who received placebo.

Another round of therapy might further delay diabetes development and “that’s what we’re hoping to do,” Herold said.

He noted that there may be reluctance to give the drug long term for fear it might throttle back the immune system too much.

“It’s been felt that to have a really effective treatment, you need a drug you give for a short period of time so people are not chronically immunosuppressed,” he said.

Provention Bio Inc is developing the drug, but additional studies will be required before regulatory agencies approve it. Currently, the immuno-therapeutic drug is not approved by the FDA.

Many new drugs cost more than $100,000 per year. If teplizumab were to delay development of type 1 diabetes for a year or so, Herold believes that some people might think it's worth the high cost.

“You have to talk to someone who has diabetes,” he said. “I think most people would tell you a day without diabetes is terrific because the disease is a 24/7 disease. You can’t sleep, you can’t eat, you can’t walk without considering it. And three quarters of the people here are children. We’re talking about a critical time in their development.”

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