What is Daclizumab: Uses, Dosage, Side Effects and More

Daclizumab is a prescription medication that was used to treat multiple sclerosis (MS) by reducing inflammation in the brain and spinal cord. This medication worked by blocking specific immune system signals that contribute to MS attacks.

However, daclizumab was voluntarily withdrawn from the market in 2018 due to serious safety concerns. While it showed promise in treating MS, rare but severe liver problems led to its discontinuation worldwide.

What is Daclizumab?

Daclizumab was a biologic medication specifically designed to treat relapsing forms of multiple sclerosis. It belonged to a class of drugs called monoclonal antibodies, which are lab-made proteins that target specific parts of your immune system.

The medication was given as a monthly injection under the skin, typically in your thigh, abdomen, or upper arm. It was marketed under the brand name Zinbryta and was considered a second-line treatment for MS patients who didn't respond well to other medications.

Unlike some MS treatments that broadly suppress your immune system, daclizumab worked more selectively. It targeted a specific protein called CD25 on certain immune cells, aiming to reduce the autoimmune attacks that damage nerve fibers in MS.

What was Daclizumab Used For?

Daclizumab was primarily prescribed for adults with relapsing forms of multiple sclerosis. This includes relapsing-remitting MS and secondary progressive MS with relapses, conditions where patients experience periods of new symptoms followed by partial or complete recovery.

Your doctor might have considered daclizumab if you had frequent MS relapses despite using other disease-modifying therapies. It was often reserved for patients who experienced breakthrough disease activity on first-line treatments like interferons or glatiramer acetate.

The medication was not approved for primary progressive MS, where symptoms steadily worsen without distinct relapses. It was also not suitable for patients with certain liver conditions or those at high risk for liver problems.

How Does Daclizumab Work?

Daclizumab worked by blocking a specific receptor called CD25 on activated T cells, which are white blood cells that play a key role in autoimmune attacks. By blocking this receptor, the medication prevented these harmful immune cells from multiplying and attacking healthy nerve tissue.

Think of it like putting a lock on a door that inflammatory cells use to enter your brain and spinal cord. When daclizumab blocked the CD25 receptor, it also increased the number of natural killer cells, which helped regulate the immune response more effectively.

This targeted approach made daclizumab moderately strong compared to other MS medications. It was more selective than broad immunosuppressants but still required careful monitoring due to its effects on immune system function.

How Should Daclizumab Be Taken?

Daclizumab was administered as a subcutaneous injection once every four weeks. The standard dose was 150 mg, delivered through a pre-filled syringe that you or a healthcare provider would inject under your skin.

The injection sites rotated between your thigh, abdomen, or upper arm to prevent skin irritation. You could take the medication with or without food, as eating didn't affect how your body absorbed the drug.

Before starting treatment, your doctor would perform blood tests to check your liver function. Regular monitoring continued throughout treatment, with blood tests typically done monthly to watch for any signs of liver problems.

The medication needed to be stored in your refrigerator and brought to room temperature before injection. Each dose came in a single-use prefilled syringe that you would dispose of safely after use.

How Long Should Daclizumab Be Taken?

The duration of daclizumab treatment varied depending on how well you responded to the medication and whether you experienced any side effects. Most patients who benefited from the treatment continued it indefinitely, as stopping could lead to a return of MS activity.

Your doctor would regularly assess your response through MRI scans and neurological examinations, typically every 6 to 12 months. If you experienced new relapses or worsening disability despite treatment, your doctor might consider switching to a different MS medication.

However, treatment would be stopped immediately if you developed signs of liver problems, such as yellowing of your skin or eyes, dark urine, or persistent nausea. The medication was ultimately withdrawn from the market due to these serious liver-related safety concerns.

What Are the Side Effects of Daclizumab?

Daclizumab could cause various side effects, ranging from mild to severe. Understanding these potential reactions helped patients and doctors make informed treatment decisions and monitor for concerning symptoms.

The most common side effects were generally manageable and included:

• Skin reactions at injection sites, including redness, swelling, or itching
• Upper respiratory tract infections like colds or sinus infections
• Rash or skin irritation beyond the injection site
• Elevated liver enzymes detected through blood tests
• Swollen lymph nodes
• Flu-like symptoms after injection

More serious side effects required immediate medical attention and included severe liver problems, which could be life-threatening. These liver issues were the primary reason the medication was withdrawn from the market.

Rare but serious complications included:

• Severe liver inflammation that could lead to liver failure
• Serious infections due to immune system suppression
• Severe skin reactions requiring hospitalization
• Autoimmune encephalitis, a rare brain inflammation
• Severe allergic reactions during or after injection

These severe side effects, particularly the liver problems, occurred in a small percentage of patients but could be fatal. This led to the voluntary withdrawal of daclizumab from all markets worldwide.

Who Should Not Take Daclizumab?

Daclizumab was not suitable for everyone with multiple sclerosis. Certain medical conditions and circumstances made the medication too risky or inappropriate for use.

You should not have taken daclizumab if you had:

• Pre-existing liver disease or significantly elevated liver enzymes
• Active infections, especially serious bacterial, viral, or fungal infections
• A history of severe allergic reactions to daclizumab or its components
• Compromised immune system from other conditions or medications
• Pregnancy or plans to become pregnant during treatment

Special caution was needed for patients with a history of depression, autoimmune conditions beyond MS, or those taking other medications that could affect the liver. Your doctor would carefully review your medical history before prescribing daclizumab.

The medication was also not recommended for patients over 65 years old, as safety data in this age group was limited. Breastfeeding mothers were advised to avoid the medication due to potential risks to the infant.

Daclizumab Brand Names

Daclizumab was marketed under the brand name Zinbryta for multiple sclerosis treatment. This was the primary commercial name used in the United States, Europe, and other countries where it was approved.

Earlier in its development, daclizumab was also known by the brand name Zenapax when it was used for preventing organ transplant rejection. However, this formulation was different from the MS version and was also discontinued.

Since the medication has been withdrawn from the market, Zinbryta is no longer available through any pharmacy or healthcare provider. Patients who were taking this medication have been transitioned to alternative MS treatments.

Daclizumab Alternatives

Since daclizumab is no longer available, several other disease-modifying therapies can effectively treat relapsing forms of multiple sclerosis. Your doctor can help you find the most suitable alternative based on your specific situation.

Current alternatives include:

• Interferon medications like Avonex, Rebif, or Plegridy
• Glatiramer acetate (Copaxone or Glatopa)
• Oral medications such as fingolimod (Gilenya) or dimethyl fumarate (Tecfidera)
• Infusion therapies like natalizumab (Tysabri) or ocrelizumab (Ocrevus)
• Newer options including alemtuzumab (Lemtrada) or cladribine (Mavenclad)

Each alternative has its own benefits and risks, and your doctor will consider factors like your disease activity, previous treatments, and personal health history. The goal is to find a medication that effectively controls your MS while minimizing side effects.

Many patients who were taking daclizumab have successfully transitioned to other treatments with continued disease control. Your healthcare team will work closely with you to ensure a smooth transition and ongoing management of your MS.

Is Daclizumab Better Than Other MS Medications?

Daclizumab showed promising effectiveness in clinical trials compared to interferon beta-1a, reducing relapse rates and new brain lesions in many patients. However, its severe safety profile ultimately outweighed these benefits.

Studies indicated that daclizumab was more effective than some first-line treatments in reducing disease activity. Patients often experienced fewer relapses and less disability progression compared to those on interferon medications.

Despite its effectiveness, the medication's withdrawal due to liver safety concerns means it's no longer considered a viable option. Current MS treatments like ocrelizumab or natalizumab may offer similar or better effectiveness with more manageable safety profiles.

The MS treatment landscape has evolved significantly since daclizumab's withdrawal. Newer medications often provide excellent disease control with better-understood and more manageable side effect profiles, making them preferable options for most patients.