Thursday, February 28, 2013

Asthma Drug Treats Chronic Hives, Severe Itch

A commonly used asthma drug, omalizumab, has shown to be effective in treating chronic hives and severe, itchy rash in adolescents and adults.
The finding came from a new study published in The New England Journal of Medicine after examining the effects of a once-a-month, high-dose injection of omalizumab on 323 subjects at 55 medical centers.

The participants had previously been taking standard antihistamine therapy, however, it did not put an end to their underlying, allergy-like response, referred to as chronic spontaneous urticaria or chronic idiopathic urticaria.

Sarbjit (Romi) Saini, M.D., a Johns Hopkins allergist and immunologist, and study co-author, said:


"Physicians and patients may now have a fast, safe and well-tolerated treatment option to consider before prescribing even more antihistamines, which can be highly sedating."


The results of the report correspond with the researchers' first presentation at the American Academy of Allergy, Asthma & Immunology's yearly meeting in San Antonio, Texas.

The majority of the study participants were female and were between 12 and 75 years old. The investigation started in 2009 and lasted until 2011.

The volunteers were randomly assigned to take one of three dosing regimens of omalizumab, or placebo, and then for fourth months after, they were observed via uniform checkups.

The investigators and the subjects were both unaware of what particular dose each person was taking throughout the trial.

Chronic hives and rash affected all participants for at least 6 months, while several had the condition for over 5 years. Hives or a severe itchy rash were still a problem in all of the patients even after taking antihistamines for seven days.

Saini, an associate professor at the Johns Hopkins University School of Medicine who has studied omalizumab since 2005, explained:


"Patients suffering with this condition need more and better treatment options because chronic hives and rash are profoundly hard to treat and can be very debilitating."


The antihistamine XYZAL(R) (Levocetirizine Dihydrochloride) was approved by the U.S. FDA for chronic hives in 2011. However, fewer than 50% of the people who are treated respond to traditional drug therapies with antihistamines, according to Saini.

Omalizumab is safer than other treatments

The novel research provides considerable proof that this first injection treatment option is not only effective, but is also safer than other drugs, including corticosteroids and the immunosuppressant cyclosporine, which are associated with possible severe and toxic reactions, such as bone thinning, infection, and high blood pressure.

The most serious reaction seen with the drug omalizumab was headache. None of the volunteers died or experienced anaphylactic shock, or had to back out of the study because of negative site effects.

About 3 million people in the United States are affected by chronic idiopathic urticaria, which sometimes involves swelling. Women are two times more likely to suffer from these "socially isolating conditions" than men, Saini said.

Some patients have a hard time breathing because they develop such bad swelling of their hands, eyes, lips, face, and throat. Some people will not even leave their house during flare-ups, meaning they have to miss work.

Hives can be treated with a single, uniform dose of the drug

The American and European researchers injected a 300-milligram dose of the treatment, marketed as Xolair, once a month for 3 months.

After one week, the initial relief from symptoms occurred. Fifty-three percent of subjects experienced a complete elimination of hives after 3 months, and 44% did not develop hives or itch again afterward.

The drug was 50% as successful at lower doses (150 milligrams, 75 milligrams and 0 milligrams - placebo) as the next larger dose, or had nearly no impact at all.

Prior studies had been conducted by Saini on the test doses, which are different from those used in omalizumab therapy for treating asthma. Saini is also the director of Johns Hopkins' medical fellowship training program in allergy and clinical immunology.

Although dosing for asthma is measured by the person's weight and blood levels of IgE antibodies, which is important to allergic responses, hives can be treated with single, uniform doses of omalizumab.

How does the treatment actually work?

Exactly how omalizumab, first approved in 2003 in the U.S. as drug for treating asthma, prevents the allergy-like responses that cause severe hives and itching is still not known, the authors explained.

However, Saini explained, they are aware that omalizumab binds up free IgE flowing in the body, and reduces the number of IgE receptors on other immune system cells that carry histamine.

In an allergic response, what normally happens is that allergens, including dust particles and pollen, bind to IgE receptors that are found on these immune system cells.

A controlled, wave-like release of histamine, a crucial triggering chemical that plays a role in inflammation, results from the process.

However, since the release of histamine seems to be more spontaneous in the itchy rash of chronic hives, the scientists believe that the histamine-carrying mast cells and basophils are abnormal.

Saini is now planning to conduct more research on the impact of omalizumab on IgE, and how it plays a role in chronic hives and rash. He hopes "to understand the underlying mechanism of the disease and explain why the drug is effective."

Written by Sarah Glynn


View drug information on Xolair.

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