Fantastic news: Last week, the US FDA officially approved teplizumab-mzwv (Tzield), the only drug that has been demonstrated to delay the onset of type 1 diabetes.
Diabetes Daily has been eagerly following Tzield for years, and last year, we supported a letter-writing campaign to the FDA in the new drug’s support. “Tzield” is the new brand name for the drug, which we have previously covered using its generic name, teplizumab.
How Tzield Works
Tzield was created decades ago, initially as an immunosuppressant. Researchers soon learned that it was especially effective at suppressing the specific T-cells known to attack the pancreatic Beta cells that are eliminated in type 1 diabetes. It has been developed as a diabetes therapy by ProventionBio, a biopharmaceutical company wholly dedicated to the prevention of autoimmune diseases.
Tzield can suppress the autoimmune attack for quite a long time. When given to patients known to carry the antibodies that cause type 1 diabetes, Tzeild delays the onset of symptoms by an average of nearly three years.
For some lucky users, the benefits will be even longer-lasting. Last we checked, some of the volunteers for PoventionBio’s earliest trials were still diabetes-free even eight years after the initial the treatment. There are no follow-up treatments; Tzield is administered once, in a 14-day course.
Who Might Benefit from Tzield
Tzield isn’t just for anybody. The drug is only indicated for patients that are already in the second stage of type 1 diabetes progression. These are people that feel completely normal but are essentially guaranteed to develop full-blown type 1 diabetes.
Experts delineate three stages of type 1 diabetes development:
- Islet cell autoimmunity, characterized by the presence of autoantibodies. During this stage, blood sugar levels are still normal and the patient experiences no symptoms.
- Beta cell destruction. The decrease in Beta cell mass reduces insulin production and results in slightly elevated blood glucose levels. The patient will still not experience any symptoms.
- Full-blown type 1 diabetes. At this stage, Beta cell mass is so low that the patient will experience overt hyperglycemia accompanied by the clinical symptoms of diabetes. Treatment with exogenous insulin will soon become absolutely necessary.
The first and second stages of diabetes development can be identified by antibody testing, a simple blood test that can confirm the absence or presence of the cells that cause the autoimmune attack that defines type 1 diabetes. Although diabetes authorities do not yet recommend routine antibody testing for anyone, many people with a family history of diabetes have taken advantage of the offer for free testing from TrialNet to learn their own risk level, or that of a family member.
The second stage can also be identified when a routine blood test shows higher than expected blood sugar levels. A diagnosis can then be confirmed with antibody testing.
At the moment, relatively few patients ever learn that they are in stage 2 — most of the time, type 1 diabetes isn’t diagnosed until symptoms have become impossible to ignore. But thanks to Tzield, that might be about to change.
How Tzield Might Change Diabetes Care
There has been relatively little push to screen patients for early cases of type 1 diabetes because, until now, there has been no validated way to slow down the disease’s onset. For the small number that have learned through antibody testing that they have an extremely high likelihood of developing type 1 diabetes, there’s little to do but keep watch for the symptoms of hyperglycemia.
With Tzield approved, doctors now have a tool to help delay the onset of the disease. As Dr. Jeremy Pettus has explained, that could move antibody screening into the mainstream.
Several experts have argued that it is cost-effective to screen all children for type 1 diabetes risk. For the minority of youths that go on to develop type 1, screening reduces the incidence of diabetic ketoacidosis (DKA), and is also likely to reduce stress and anxiety. With Tzield now approved, the case is even better.
Tzield can delay the onset of type 1 diabetes symptoms in people that have already developed early asymptomatic cases of type 1 diabetes.
The new drug is indicated for patients over the age of seven. It is administered with an IV infusion, once daily for a total of two weeks. The 14-day course is the only dose.
Tzield could help usher in a future in which screening for type 1 diabetes risk becomes a routine element of checkups. Tzield works — now we have to see if doctors and insurers can be convinced that screening for risk is worth the time, effort, and money.