The biologic drug omalizumab (Xolair®) is approved to treat some people with chronic hives. Xolair is approved for people over age 12 whose symptoms are not controlled by H1 antihistamines. It only treats spontaneous or idiopathic hives.1
Biologics are drugs made from living cells. These cells can come from parts of the blood, proteins, viruses, or tissue. The process of making biologics turns these cells into drugs that can prevent, treat, and cure disease.
There are many types of biologics, such as vaccines and blood transfusions. The most important biologics in chronic hives are monoclonal antibodies. These are proteins designed to attach to a certain target protein in your cells.2
How do biologics work?
Omalizumab is a monoclonal antibody biologic designed to attach to a protein called immunoglobulin E (IgE). It binds IgE in the bloodstream, which causes the body to break it down. This prevents IgE from causing certain immune cells (mast cells) to release histamine and other chemicals. These chemicals cause symptoms of chronic hives.3,4
Clinical trials have shown that omalizumab can be effective for many people with chronic hives who do not respond well to H1 antihistamines. About 76 percent of people have meaningful symptom relief after 12 week of treatment.3,5,6
Symptoms may return after stopping treatment with omalizumab. However, chronic hives tend to go away within a few years even without treatment. This makes it hard to determine the long-term efficacy of omalizumab.3
Examples of biologics
As of 2023, the only biologic drug approved by the US Food and Drug Administration (FDA) for chronic hives is omalizumab.4
Other biologic drugs are currently being studied for treating chronic hives. Research has been mixed and more studies are needed.4,7
What are the possible side effects?
Omalizumab has very few serious side effects. This is why it is the most common treatment used when H1 antihistamines are not effective. However, some side effects are possible, including:1
- Nausea
- Upper respiratory tract infections
- Joint pain
- Headache
- Cough
Omalizumab has a boxed warning, the strictest warning from the FDA. It has this warning because it may cause severe allergic reactions (anaphylaxis). A reaction can occur after any dose and can be life-threatening. Go to an emergency room right away if you notice any signs of anaphylaxis, such as:1
- Wheezing, shortness of breath, or chest tightness
- Low blood pressure, dizziness, or fainting
- Flushing or feeling warm
- Swelling of the throat or tongue
Your doctor will give you information about treating anaphylaxis. They should also give you an epinephrine auto-injector to use.3
These are not all the possible side effects of Omalizumab. Talk to your doctor about what to expect when taking Omalizumab. You also should call your doctor if you have any changes that concern you when taking Omalizumab.
Other things to know
Take omalizumab exactly as your doctor prescribes. They will usually suggest taking it every 4 weeks. They may reduce your H1 antihistamines if you respond well to omalizumab. Your doctor may then adjust your omalizumab treatment depending on how you respond. For example:3
- If symptoms go away after taking omalizumab, your doctor may reduce the frequency of your doses
- If your symptoms are still gone with 8-week intervals between doses, your doctor may stop treatment
- If your symptoms are only somewhat controlled, your doctor may give you higher or more frequent doses
- If your symptoms are not controlled, your doctor may stop treatment and try other options
In 2021, the FDA approved omalizumab for self-administration. Your doctor or caregiver can teach you how to give yourself omalizumab at home. They will decide if you are eligible for self-administration based on a number of factors, such as:1
- Your history of anaphylaxis and allergic reactions
- Whether you or a caregiver can identify signs of anaphylaxis
- Whether you or a caregiver can treat anaphylaxis
- Whether you or a caregiver can perform injections with proper technique
Unfortunately, omalizumab is expensive. The cost for a single dose is more than $1,000. Many people with chronic hives can be treated with cheaper drugs, such as antihistamines. This is one reason why omalizumab is not yet accessible to many people with chronic hives.8 Your medical insurance may cover some or all the costs of the drug. Work with your doctor about what option is best.
Before taking omalizumab, tell your doctor if you:1
- Have any allergies, especially to latex
- Have sudden breathing problems
- Have ever had a severe allergic reaction (anaphylaxis)
- Have ever had a parasitic infection or cancer
- Are pregnant or planning to become pregnant
Before beginning treatment for chronic hives, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.