Drug makers Biogen and AbbVie withdrew their multiple sclerosis drug after reports that Zinbryta side effects possibly included serious brain inflammation.

At least 12 patients around the world were diagnosed with encephalitis allegedly linked to their Zinbryta prescription. Three of the identified cases ended in death.

Biogen and AbbVie announced a voluntary recall of Zinbryta (daclizumab) on March 2, 3018. The U.S. Food and Drug Administration assisted with the drug’s removal from the market until April 30, 2018, at which point the drug was no longer available.

The companies released a statement that said in part, “Given the nature and complexity of adverse events being reported, characterizing the evolving benefit/risk profile of Zinbryta will not be possible going forward given the limited number of patients being treated.”

Multiple sclerosis is a disease that causes the patient’s immune system to attack and damage the protective covering around the nerve cells in the brain and spinal cord, which together are called the central nervous system. Zinbryta worked to interfere with the immune system’s attack by binding with the immune cells, which, in effect, blocked the immune cells from attacking the central nervous system.

In many patients, multiple sclerosis causes periods of difficulty functioning followed by periods of remission. Most patients see their first symptoms of the disease between the ages of 20 and 40 years old.

Allegations of Serious Zinbryta Side Effects

Since its entry to the medical market in 2016, Zinbryta has raised red flags due to potential complications linked to the drug. Possible serious Zinbryta side effects were known to include liver toxicity and risks of Stevens Johnson Syndrome (SJS), a serious skin rash allergic reaction.

SJS quickly can progress into Toxic Epidermal Necrolysis (TEN), a possibly life-threatening condition that causes the membranes and skin to develop blisters that resemble severe burns from the inside out.

According to the FDA, the most common Zinbryta side effects include cold symptoms, increased risk of upper respiratory tract infections, rash, throat pain and eczema.

Because of the risks of serious Zinbryta issues, the FDA recommended it only when a patient had not responded to two or more other multiple sclerosis drugs. Zinbryta was also available only through a restricted distribution program under a Risk Evaluation and Mitigation Strategy overseen by the FDA.

Biogen and AbbVie allegedly did not warn of any risks of brain inflammation from the use of the drug.

In most occurrences, encephalitis is caused by a bacterial or viral infection that causes inflammation of the brain. A related condition is meningitis, which is inflammation of the membranes that cover the brain.

Encephalitis symptoms resemble the flu and may last two or three weeks, but may continue to worsen. Even though 12 cases of encephalitis linked to Zinbryta problems were found worldwide, doctors believe there might be more cases that were not linked to the drug at the time.

Patients experiencing the onset of encephalitis might not have any symptoms, but some patients could suffer from fatigue, muscle pain, fever, disorientation or hallucinations. Other possible signs are irritability, light sensitivity, a stiff neck, a headache or onset of seizures.