Drug manufacturers Biogen and Abbvie are currently warning the patient population that if they have been prescribed Zinbryta (daclizumab), they should be wary of encephalitis symptoms.

Biogen and Abbvie announced they were withdrawing Zinbryta from the global market on March 2, 2018, after learning of injury reports from patients who allegedly developed meningoencephalitis or encephalitis symptoms.

Encephalitis is a condition in which the brain tissue becomes inflamed, caused by either bacterial or viral infection and occasionally from an autoimmune disorder. Encephalitis symptoms vary between patients, but this condition is potentially fatal and should be treated as soon as possible.

Encephalitis can be categorized as either primary or secondary, with primary encephalitis occurring when a virus directly infects the brain and spinal cord. Secondary encephalitis occurs when another part of the body becomes infected, and eventually travels to the brain.

Several different viruses have been linked to encephalitis including common viruses, childhood viruses, and arboviruses. Arboviruses are viruses that are transmitted by insect bites, which also includes West Nile virus and Colorado tick fever.

Encephalitis has also been recently associated with adverse drug reactions to Zinbryta, with the drug manufacturers warning against encephalitis symptoms including:

• Muscle Pain or Weakness
• Fatigue
• Fever
• Coordination Problems
• Disorientation
• Mental Confusion
• Nausea
• Vomiting
• Delirium or Hallucination
• Irritability
• Sensitivity to Light
• Headache
• Stiff Neck
• Seizures
• Lack of Consciousness

It is important to note that even if Zinbryta patients survive their ordeal, they could be left with permanent encephalitis symptoms including paralysis, loss of brain function, and chronic issues with speech, behavior, memory, and balance.

Overview of Zinbryta Encephalitis

Encephalitis symptoms are essentially flu like symptoms that tend to last between two to three weeks. These symptoms can get worse in serious cases. At least 12 cases of Zinbryta encephalitis have been reported from around the world, with three of them being fatal.

Zinbryta was approved by the FDA in 2016, to be a treatment medication for adult patients with relapsing multiple sclerosis (MS). Zinbryta is typically prescribed to patients who have not responded to other MS treatment drugs.

Zinbryta works by binding immune cells and reducing activity of the cells attacking the patient’s immune systems. Multiple sclerosis is a condition in which the body’s immune system attacks the protective sheath surrounding cells in the central nervous system.

Even though Zinrbyta is an important treatment option for patients with severe multiple sclerosis, serious side effects have been associated with the medication since it entered the market. The Zinbryta warning label had received a black box warning regarding liver damage and other immune related disorders.

The FDA states that it is currently working with Biogen and Abbvie to ensure “a well-organized withdrawal from the market in the United States, and to ensure that healthcare professionals have the information they need to carefully transition their patients using Zinbryta to another treatment.”

The voluntary recall was issued after the European Medicines Agency (EMA) had found 12 cases of alleged Zinbryta encephalitis and meningoencephalitis.

Zinbryta patients who developed encephalitis symptoms or other serious side effects may be able to file legal action against the manufacturers for allegedly failing to warn them against the full scope of potential complications.