The first drug to delay the onset of type 1 diabetes in those nearly certain to develop the autoimmune disease has been approved by the U.S. Food and Drug Administration (FDA), the federal agency announced Thursday (Nov. 17).
In type 1 diabetes, the immune system progressively wipes out insulin-producing cells, called beta cells. The new treatment, called teplizumab-mzwv (brand name Tzield), is a lab-made protein that behaves like an antibody made by the human immune system. Once in the body, the so-called monoclonal antibody latches onto immune cells called T cells and reprograms them so they don't aggressively attack beta cells in the pancreas, according to a statement from drugmaker ProventionBio. At the same time, it boosts the number of immune cells that counteract such attacks.
Insulin acts as a key that unlocks cells so that sugar from the bloodstream can enter them. When the body doesn't make enough insulin, blood sugar levels skyrocket.
Before a person develops full-blown type 1 diabetes, they progress through several preliminary stages of disease, according to Emory University School of Medicine. In stage 1, beta cell-targeting antibodies begin to appear but blood sugar levels remain normal, and in stage 2, blood sugar levels become a little elevated in some situations, but people still show no diabetes symptoms.
Related: What is normal blood sugar?
By stage 3, a bulk of the beta cells have been destroyed and people show symptoms, such as extremely elevated blood sugar levels, frequent urination, weight loss and thirst, and they can sometimes develop a life-threatening condition called diabetic ketoacidosis. Most people receive a type 1 diagnosis at this stage. People are most often diagnosed as children or young adults, but type 1 diabetes can develop at any age.
In a clinical trial, teplizumab-mzwv delayed the transition from stage 2 to stage 3 for a little more than two years, compared with a placebo treatment, according to the FDA. Two years was the median time until diagnosis, meaning some participants transitioned to stage 3 sooner and some did so later.
The antibody is now approved for use in people ages 8 and older with stage 2 type 1 diabetes.
"The drug's potential to delay clinical diagnosis of type 1 diabetes may provide patients with months to years without the burdens of disease," Dr. John Sharretts, director of the Division of Diabetes, Lipid Disorders, and Obesity in the FDA's Center for Drug Evaluation and Research, said in the agency's statement.
The trial included 76 participants who were between 8 and 49 years old and had stage 2 type 1 diabetes; more than 70% of the participants were younger than age 18, according to ProventionBio. The participants were randomly split into two groups, one of which received daily IV infusions of teplizumab-mzwv for two weeks while the other group received placebo infusions.
The most common side effects of teplizumab-mzwv were rash, headache and a decrease in the numbers of certain immune cells, according to ProventionBio. In most patients who experienced the latter side effect, these immune cell counts began rebounding within a week of them concluding treatment and fully recovered within a few months.
Patients who take teplizumab-mzwv should be monitored for signs of a potentially dangerous reaction called "cytokine release syndrome," in which T cells suddenly unleash a flood of inflammatory molecules into the bloodstream. This occurred in some trial participants, ProventionBio cautioned.
Patients should also be monitored for signs of serious infection, as their immune protection may be lower than usual during and following treatment, and any "hypersensitivity reactions," such as vomiting or swelling beneath the skin (angioedema). And because teplizumab-mzwv may interfere with immune response to vaccination, all age-appropriate vaccinations should be given prior to the treatment's start.
Teplizumab-mzwv costs $13,850 a vial, which adds up to a total of $193,000 over the 14-day treatment, USA Today reported.
