On Thursday Nov 17, 2022, the Food and Drug Administration approved the drug teplizumab, which will be sold under the brand name Tzield. Tzield is a humanized monoclonal antibody that binds to the CD3 marker molecules on the surface of specific immune cells. Its mechanism of action binds to and deactivates immune cells and thus prevents their destructive action on the pancreatic islet cells. It does this by binding weakly to the T cell receptor-CD3 complex, which initiates a weak signaling pathway. This action can delay the onset of full Type 1 diabetes. Tzield is approved for use in people ages 8 years and older who are in Stage 2 of Type 1 diabetes. In that stage, doctors can measure antibodies that attack insulin-producing beta cells in the person’s blood, and they have abnormal blood sugar levels, but their body can still make insulin.
The three stages of Type 1 diabetes are:
STAGE 1 is the start of Type 1 diabetes. Individuals test positive for two or more diabetes-related autoantibodies. The immune system has already begun attacking the insulin-producing beta cells, although there are no symptoms and blood sugar remains normal.
STAGE 2 includes individuals who have two or more diabetes-related autoantibodies, but now, blood sugar levels have become abnormal due to increasing loss of beta cells. There are still no outward symptoms.
STAGE 3 is when clinical diagnosis typically takes place. By this time, there is significant beta cell loss and individuals generally show common symptoms of Type 1 diabetes, which include frequent urination, excessive thirst, weight loss, and fatigue.
The earlier diagnosis is made in this disease process, the sooner intervention can take place, and the more beta cells are likely to remain. More beta cells may lead to better outcomes regarding blood sugar control and reduction of long-term complications. Tzield is approved for people who don’t have any outward symptoms of the disease and may not know they’re on the road to getting it unless diagnosed through blood tests.
When one child is diagnosed with Type 1 diabetes, it is recommended that siblings also be tested for antibodies. Family members have a 15 times greater risk of being diagnosed than someone with no family history. When a person has markers for autoimmune disease and episodes of uncontrolled blood sugar, the five-year risk for progression to insulin-dependent symptomatic disease is 75%. The lifetime risk of developing insulin-dependent diabetes is nearly 100%. For the symptomatic patient just diagnosed with Type 1 it’s too late for Tzield, but their asymptomatic siblings who test positive for antibodies will be able to benefit. In clinical trials, the newly approved treatment delayed Stage 3 disease onset for about two years compared with the placebo.
Tzield is a 14 day regimen of IV infusions taking about 30 minutes each to administer. One of the side effects of Tzield is a decrease in a white blood cell count, which health experts say could increase the risk of developing severe disease from opportunistic infections. But the trial showed cell counts began rising again seven days after treatment was completed and returned to pre-treatment counts a few months later.
The kicker is the cost of this treatment which is $13,850 a vial for a total of $193,000 for the recommended 14-day treatment. Because it’s new, most insurance companies will probably not cover it yet. However, if a patient needs help paying for Tzield, Provention Bio’s Patient Assistance Program may be able to help. While co-pay amounts vary based on individual coverage, with the Provention Bio Copay Program, commercially or privately insured individuals enrolled in COMPASS may pay as little as $0 for Tzield. If a patient qualifies, their COMPASS Navigator can help enroll them into the program so they may be able to lower their out-of-pocket costs. Interested patients and healthcare providers can contact COMPASS for questions about our available assistance programs at COMPASS@proventionbio.com and 1-844-778-2246, Monday through Friday from 8AM-8PM EST.