Xolair

Xolair is the brand name for omalizumab, a humanized monoclonal antibody that targets immunoglobulin E (IgE). By binding to IgE, omalizumab prevents IgE from attaching to FcεRI receptors on the surface of mast cells and basophils, reducing the release of inflammatory mediators involved in allergic reactions. This mechanism makes Xolair useful as a targeted anti-IgE therapy for allergic conditions.

Indications include moderate-to-severe persistent allergic asthma that remains inadequately controlled with inhaled corticosteroids, as well as chronic spontaneous urticaria (chronic hives) that persists despite antihistamine treatment. Dosing is individualized and typically administered by subcutaneous injection every two to four weeks. For asthma, the dose and frequency depend on body weight and baseline IgE levels; for chronic spontaneous urticaria, dosing is based on approved fixed regimens. In all indications, injections are usually given in a healthcare setting with monitoring, particularly after the first dose, to manage the rare risk of anaphylaxis.

Efficacy evidence supports a reduction in asthma exacerbations and improved symptom control in eligible patients, along with reductions in urticaria severity for CSU when used according to guidelines. Common adverse effects include injection-site reactions, headaches, and fatigue. Serious but rare risks include anaphylaxis and hypersensitivity reactions, which can occur at any time during treatment, hence the need for post-injection observation and patient education about early symptoms.

Xolair has been approved in multiple regions since the early 2000s and is used in selected pediatric and adult populations, reflecting its role as a targeted option for IgE-mediated allergic diseases.