XOLAIR

What it is

Xolair (omalizumab) is a recombinant DNA-derived humanised monoclonal antibody produced in Chinese hamster ovary cells that selectively binds to human immunoglobulin E (IgE). It is supplied as a clear to slightly opalescent, colourless to pale brownish-yellow preservative-free solution in a pre-filled syringe or pre-filled pen. It is also available as a sterile, white, preservative-free lyophilised powder that is reconstituted with water for injections and administered as a subcutaneous injection. Xolair is for subcutaneous administration only and must not be administered by the intravenous or intramuscular route.

Approved indications

— In children aged 6 to <12 years, Xolair is indicated as add-on therapy to improve asthma control in patients with severe allergic asthma who have documented exacerbations despite daily high dose inhaled corticosteroids, and who have immunoglobulin E levels corresponding to the recommended dose range. — Xolair is indicated for the management of adult and adolescent patients with moderate to severe allergic asthma, who are already being treated with inhaled steroids, and who have serum immunoglobulin E levels corresponding to the recommended dose range. — Xolair is indicated as add-on treatment in adult patients (18 years of age and above) for the treatment of severe chronic rhinosinusitis with nasal polyps with inadequate response to intranasal corticosteroids. — Xolair is indicated for adults and adolescents (12 years of age and above) with chronic spontaneous urticaria who remain symptomatic despite H1 antihistamine treatment.

Dosing overview

The appropriate dose and dosing frequency of Xolair is determined by baseline immunoglobulin E (IgE) (IU/mL), measured before the start of treatment, and body weight (kg). Based on these measurements 75 to 600 mg of Xolair in 1 to 4 injections may be needed for each administration. Xolair is administered subcutaneously every two or four weeks according to the dose determination chart. For chronic spontaneous urticaria, the recommended dose is 300 mg by subcutaneous injection every four weeks, although some patients may achieve control of their symptoms with a dose of 150 mg every four weeks. Xolair should be used as add-on therapy to H1 antihistamine treatment.

Key safety warnings

As with any protein, local or systemic allergic reactions, including anaphylaxis, may occur. Anaphylactic reactions were rare in clinical trials. In post-marketing experience, anaphylaxis and anaphylactoid reactions have been reported following the first and subsequent administrations of Xolair. Most of these reactions occurred within 2 hours after Xolair administration, some occurred beyond 2 hours and even beyond 24 hours after injections. The majority of anaphylactic reactions occurred within the first 3 doses of Xolair. A history of anaphylaxis unrelated to omalizumab may be a risk factor for anaphylaxis following Xolair administration. It is recommended that patients with a known history of anaphylaxis have each dose of Xolair administered in a setting where there is treatment for anaphylaxis available. Serum sickness and serum sickness-like reactions, which are delayed allergic type III reactions, have rarely been seen in patients treated with humanized monoclonal antibodies including omalizumab. The onset has typically been 1-5 days after administration of the first or subsequent injections, also after long duration of treatment. Symptoms suggestive of serum sickness include arthritis/arthralgia, rash (urticaria or other forms), fever and lymphadenopathy. Patients with severe asthma may rarely present systemic hypereosinophilic syndrome or allergic eosinophilic granulomatous vasculitis (Churg-Strauss syndrome). In rare cases, patients on therapy with anti-asthma agents, including omalizumab, may present or develop systemic eosinophilia and vasculitis. A causal association between Xolair and these underlying conditions has not been established. These events are commonly associated with the reduction of oral corticosteroid therapy. At serum concentrations in excess of maximum human exposure used in pivotal clinical trials, dose-related thrombocytopenia occurred in 2 out of 4 non-human primate species studied. The thrombocytopenia was more pronounced in juvenile animals. No Xolair-related thrombocytopenia has been observed in clinical trials, but it has been reported in the post-market setting. Xolair should be used with caution in patients with thrombocytopenia and patients with a history of thrombocytopenia. It is recommended that patients have a platelet count before commencing therapy with Xolair and then periodically during treatment with Xolair.

Contraindications

Hypersensitivity to omalizumab or any other component of the formulation is a contraindication to Xolair.

PBS listing

Xolair is listed on the PBS in the following strengths and forms: 75 mg in 0.5 mL single dose pre-filled syringe, 75 mg in 0.5 mL single dose pre-filled pen, 150 mg in 1 mL single dose pre-filled pen, and 300 mg in 2 mL single dose pre-filled pen. All listings require authority approval. Ex-manufacturer prices are A$104.54 (75 mg), A$209.07 (150 mg), and A$418.14 (300 mg).

Regulatory history

Xolair omalizumab powder for injection was first listed on the ARTG on 13 June 2002 (ARTG 82744 for 150 mg strength) and 10 January 2006 (ARTG 115399 for 75 mg strength). Solution for injection pre-filled syringes were first listed on 16 August 2013 for the 150 mg strength (ARTG 201126) and 19 August 2013 for the 75 mg strength (ARTG 201124). Pre-filled pen formulations were first listed on 4 September 2024 across 75 mg, 150 mg, and 300 mg strengths. In November 2015, the PBAC recommended Xolair for severe allergic asthma with expanded listing to include patients with baseline IgE of 30–75 IU/mL under the Section 100 Highly Specialised Drugs Program. The same month, the PBAC recommended Xolair for severe uncontrolled chronic idiopathic urticaria under Section 100 on a cost-minimisation analysis compared with cyclosporin. In July 2016, the PBAC recommended Xolair for paediatric severe allergic asthma in patients aged 6 to <12 years under the Section 100 program. In November 2017, the PBAC recommended expansion of the listing to include patients aged 6 years and older with severe allergic asthma. An AusPAR for the chronic rhinosinusitis with nasal polyps indication was approved on 12 March 2021. In May 2025, the PBAC recommended Xolair for initial and continuing treatment of chronic rhinosinusitis with nasal polyps.