Omalizumab: Uses, Dosage, Side Effects and More

Generic Medicine Info Patient Medicine Information

This information is not country-specific. Please refer to the Hong Kong prescribing information.

Generic Medicine Info

Indications and Dosage

Subcutaneous
Allergic asthma

Adult: In patients with moderate to severe persistent cases whose symptoms are inadequately controlled with inhaled corticosteroids (ICS): Dosage is based on patient's weight and baseline serum-IgE concentrations as follows:

Baseline IgE Serum Level (international units/mL)	Weight (kg)	Dosage
≥30-100	≥20-40	75 mg every 4 weeks.
	>40-90	150 mg every 4 weeks.
	>90-150	300 mg every 4 weeks.
>100-200	≥20-40	150 mg every 4 weeks.
	>40-90	300 mg every 4 weeks.
	>90-125	450 mg every 4 weeks.
	>125-150	600 mg every 4 weeks.
>200-300	≥20-30	150 mg every 4 weeks.
	>30-40	225 mg every 4 weeks.
	>40-60	300 mg every 4 weeks.
	>60-90	450 mg every 4 weeks.
	>90-125	600 mg every 4 weeks.
	>125-150	375 mg every 2 weeks.
>300-400	≥20-30	225 mg every 4 weeks.
	>30-40	300 mg every 4 weeks.
	>40-70	450 mg every 4 weeks.
	>70-90	600 mg every 4 weeks.
	>90-125	450 mg every 2 weeks.
	>125-150	525 mg every 2 weeks.
>400-500	≥20-25	225 mg every 4 weeks.
	>25-30	300 mg every 4 weeks.
	>30-50	450 mg every 4 weeks.
	>50-70	600 mg every 4 weeks.
	>70-90	375 mg every 2 weeks.
	>90-125	525 mg every 2 weeks.
	>125-150	600 mg every 2 weeks.
>500-600	≥20-30	300 mg every 4 weeks.
	>30-40	450 mg every 4 weeks.
	>40-60	600 mg every 4 weeks.
	>60-70	375 mg every 2 weeks.
	>70-90	450 mg every 2 weeks.
	>90-125	600 mg every 2 weeks.
>600-700	≥20-25	300 mg every 4 weeks.
	>25-30	225 mg every 2 weeks.
	>30-40	450 mg every 4 weeks.
	>40-50	600 mg every 4 weeks.
	>50-60	375 mg every 2 weeks.
	>60-80	450 mg every 2 weeks.
	>80-90	525 mg every 2 weeks.
>700-800	≥20-30	225 mg every 2 weeks.
	>30-40	300 mg every 2 weeks.
	>40-50	375 mg every 2 weeks.
	>50-70	450 mg every 2 weeks.
	>70-80	525 mg every 2 weeks.
	>80-90	600 mg every 2 weeks.
>800-900	≥20-30	225 mg every 2 weeks.
	>30-40	300 mg every 2 weeks.
	>40-50	375 mg every 2 weeks.
	>50-60	450 mg every 2 weeks.
	>60-70	525 mg every 2 weeks.
	>70-80	600 mg every 2 weeks.
>900-1,000	≥20-25	225 mg every 2 weeks.
	>25-30	300 mg every 2 weeks.
	>30-40	375 mg every 2 weeks.
	>40-50	450 mg every 2 weeks.
	>50-60	525 mg every 2 weeks.
	>60-70	600 mg every 2 weeks.
>1,000-1,100	≥20-25	225 mg every 2 weeks.
	>25-30	300 mg every 2 weeks.
	>30-40	375 mg every 2 weeks.
	>40-50	450 mg every 2 weeks.
	>50-60	600 mg every 2 weeks.
>1,100-1,200	≥20-30	300 mg every 2 weeks.
	>30-40	450 mg every 2 weeks.
	>40-50	525 mg every 2 weeks.
	>50-60	600 mg every 2 weeks.
>1,200-1,300	≥20-25	300 mg every 2 weeks.
	>25-30	375 mg every 2 weeks.
	>30-40	450 mg every 2 weeks.
	>40-50	525 mg every 2 weeks.
>1,300-1,500	≥20-25	300 mg every 2 weeks.
	>25-30	375 mg every 2 weeks.
	>30-40	525 mg every 2 weeks.
	>40-50	600 mg every 2 weeks.

Dosage, treatment and administration recommendations may vary among countries and between individual products (refer to specific product guidelines).
Child: 6-<12 years As add-on therapy to improve asthma control with severe persistent cases who have a positive skin test or in vitro reactivity to a perennial aeroallergen and frequent daytime symptoms or night-time awakenings and who have had multiple documented severe asthma exacerbations despite daily high-dose ICS, plus long-acting inhaled β₂-agonist: Same as adult dose. ≥12 years Same as adult dose. Dosage, treatment and administration recommendations may vary among countries and between individual products (refer to specific product guidelines).

Subcutaneous
Chronic rhinosinusitis with nasal polyps

Adult: As add-on therapy with intranasal corticosteroids: Dosage is based on patient's weight and baseline serum-IgE concentrations as follows:

Baseline IgE Serum Level (international units/mL)	Weight (kg)	Dosage
≥30-100	≥20-40	75 mg every 4 weeks.
	>40-90	150 mg every 4 weeks.
	>90-150	300 mg every 4 weeks.
>100-200	≥20-40	150 mg every 4 weeks.
	>40-90	300 mg every 4 weeks.
	>90-125	450 mg every 4 weeks.
	>125-150	600 mg every 4 weeks.
>200-300	≥20-30	150 mg every 4 weeks.
	>30-40	225 mg every 4 weeks.
	>40-60	300 mg every 4 weeks.
	>60-90	450 mg every 4 weeks.
	>90-125	600 mg every 4 weeks.
	>125-150	375 mg every 2 weeks.
>300-400	≥20-30	225 mg every 4 weeks.
	>30-40	300 mg every 4 weeks.
	>40-70	450 mg every 4 weeks.
	>70-90	600 mg every 4 weeks.
	>90-125	450 mg every 2 weeks.
	>125-150	525 mg every 2 weeks.
>400-500	≥20-25	225 mg every 4 weeks.
	>25-30	300 mg every 4 weeks.
	>30-50	450 mg every 4 weeks.
	>50-70	600 mg every 4 weeks.
	>70-90	375 mg every 2 weeks.
	>90-125	525 mg every 2 weeks.
	>125-150	600 mg every 2 weeks.
>500-600	≥20-30	300 mg every 4 weeks.
	>30-40	450 mg every 4 weeks.
	>40-60	600 mg every 4 weeks.
	>60-70	375 mg every 2 weeks.
	>70-90	450 mg every 2 weeks.
	>90-125	600 mg every 2 weeks.
>600-700	≥20-25	300 mg every 4 weeks.
	>25-30	225 mg every 2 weeks.
	>30-40	450 mg every 4 weeks.
	>40-50	600 mg every 4 weeks.
	>50-60	375 mg every 2 weeks.
	>60-80	450 mg every 2 weeks.
	>80-90	525 mg every 2 weeks.
>700-800	≥20-30	225 mg every 2 weeks.
	>30-40	300 mg every 2 weeks.
	>40-50	375 mg every 2 weeks.
	>50-70	450 mg every 2 weeks.
	>70-80	525 mg every 2 weeks.
	>80-90	600 mg every 2 weeks.
>800-900	≥20-30	225 mg every 2 weeks.
	>30-40	300 mg every 2 weeks.
	>40-50	375 mg every 2 weeks.
	>50-60	450 mg every 2 weeks.
	>60-70	525 mg every 2 weeks.
	>70-80	600 mg every 2 weeks.
>900-1,000	≥20-25	225 mg every 2 weeks.
	>25-30	300 mg every 2 weeks.
	>30-40	375 mg every 2 weeks.
	>40-50	450 mg every 2 weeks.
	>50-60	525 mg every 2 weeks.
	>60-70	600 mg every 2 weeks.
>1,000-1,100	≥20-25	225 mg every 2 weeks.
	>25-30	300 mg every 2 weeks.
	>30-40	375 mg every 2 weeks.
	>40-50	450 mg every 2 weeks.
	>50-60	600 mg every 2 weeks.
>1,100-1,200	≥20-30	300 mg every 2 weeks.
	>30-40	450 mg every 2 weeks.
	>40-50	525 mg every 2 weeks.
	>50-60	600 mg every 2 weeks.
>1,200-1,300	≥20-25	300 mg every 2 weeks.
	>25-30	375 mg every 2 weeks.
	>30-40	450 mg every 2 weeks.
	>40-50	525 mg every 2 weeks.
>1,300-1,500	≥20-25	300 mg every 2 weeks.
	>25-30	375 mg every 2 weeks.
	>30-40	525 mg every 2 weeks.
	>40-50	600 mg every 2 weeks.

Dosage, treatment and administration recommendations may vary among countries and between individual products (refer to specific product guidelines).

Subcutaneous
Chronic spontaneous urticaria

Adult: As add-on therapy in patients with inadequate response to H₁ antihistamine therapy: 150 mg or 300 mg every 4 weeks. Dosage, treatment and administration recommendations may vary among countries and between individual products (refer to specific product guidelines).
Child: ≥12 years Same as adult dose.

What are the brands available for Omalizumab in Hong Kong?

Xolair

Reconstitution

Powder for solution for inj: Reconstitute vial labelled as 150 mg with sterile water for inj by adding 1.4 mL of sterile water for inj to an upright vial. Keep the vial in an upright position, then gently swirl for approx 1 minute to evenly wet the powder. Do not shake. Gently swirl the vial for 5-10 seconds approx every 5 minutes until the powder dissolves (generally takes 15-20 minutes to completely dissolve). Invert the vial for 15 seconds for the solution to drain toward the stopper, then remove the solution by inserting a new syringe into the inverted vial. Expel air, large bubbles, and any excess solution to obtain a final concentration of 150 mg/1.2 mL. Refer to specific product guidelines.

Contraindications

Hypersensitivity.

Special Precautions

Patient with high risk factors for helminth infection (particularly those travelling to areas with endemic cases of helminthic infections); autoimmune diseases, immune complex-mediated conditions; history of anaphylaxis unrelated to omalizumab. Not indicated for the treatment of acute bronchospasm, status epilepticus, acute asthma exacerbations, or other allergic conditions. Omalizumab concentrations may vary among different formulations; use extra precaution during drug formulation selection and dose volume calculations (refer to specific product guidelines). Renal and hepatic impairment. Children. Pregnancy and lactation.

Adverse Reactions

Significant: Systemic hypereosinophilic syndrome, allergic eosinophilic granulomatous vasculitis (Churg-Strauss syndrome), fever, arthritis, arthralgia, rash, lymphadenopathy; serum sickness, serum sickness-like reactions, malignant neoplasms; cerebrovascular events (including TIA and ischaemic stroke).
Gastrointestinal disorders: Upper abdominal pain, dyspepsia, diarrhoea, nausea.
General disorders and administration site conditions: Inj site reactions (e.g. swelling, erythema, pain); influenza-like illness, fatigue.
Investigations: Increased weight.
Nervous system disorders: Headache, paraesthesia, somnolence, dizziness.
Respiratory, thoracic and mediastinal disorders: Pharyngitis, coughing, sinusitis, URTI.
Skin and subcutaneous tissue disorders: Photosensitivity, pruritus.
Vascular disorders: Flushing.
Potentially Fatal: Anaphylaxis, presenting as bronchospasm, hypotension, syncope, urticaria, and/or angioedema of the throat or tongue.

Monitoring Parameters

Evaluate and treat parasitic infections before treatment initiation. Assess for signs and symptoms of hypersensitivity reactions, vasculitis or hypereosinophilia. When used for allergic asthma or chronic rhinosinusitis with nasal polyps: Obtain serum total IgE level prior to treatment initiation; body weight prior and during therapy.

Drug Interactions

May reduce the efficacy of antihelminthic drugs.

Action

Description:
Overview: Omalizumab is a recombinant DNA-derived humanised monoclonal antibody.
Mechanism of Action: Omalizumab binds specifically to immunoglobulin E (IgE) and inhibits its binding to the high-affinity IgE receptors (FceRI) on mast cells, basophils and dendritic cells, resulting in decreased amount of free IgE available to trigger the allergic cascades.
Pharmacodynamics: Studies have shown that omalizumab reduces serum free IgE levels in a dose-dependent manner. However, total serum IgE concentrations are increased due to omalizumab-IgE complexes are eliminated more slowly than free IgE.
Onset: Approx 12-16 weeks (response to therapy).
Pharmacokinetics:
Absorption: Slowly absorbed after SC inj. Bioavailability: Approx 62%. Time to peak plasma concentration: 7-8 days.
Distribution: Crosses the placenta and enters breast milk. Volume of distribution: 78 ± 32 mL/kg.
Metabolism: Degraded in the liver by reticuloendothelial system and endothelial cells.
Excretion: Mainly via hepatic degradation; bile (intact IgG). Elimination half-life: Approx 26 days.

Storage

Prefilled syringe or pen/Intact vial: Store between 2-8°C. Do not freeze. Protect from light. Reconstituted solution for inj (from the vial): Store between 2-8°C for up to 8 hours or ≤30°C for up to 4 hours. Storage recommendations may vary among countries and between individual products (refer to specific product guidelines).

MIMS Class

Antiasthmatic & COPD Preparations / Antihistamines & Antiallergics

ATC Classification

R03DX05 - omalizumab ; Belongs to the class of other systemic drugs used in the treatment of obstructive airway diseases.

References

Brayfield A, Cadart C (eds). Omalizumab. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 08/09/2025.

Joint Formulary Committee. Omalizumab. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 08/09/2025.

Novartis New Zealand Limited. Xolair 75 mg and 150 mg Solution for Injection in Pre-filled Syringe data sheet 05 July 2024. Medsafe. http://www.medsafe.govt.nz. Accessed 09/09/2025.

Omalizumab. UpToDate Lexidrug, AHFS DI (Adult and Pediatric) Online. American Society of Health-System Pharmacists, Inc. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 08/09/2025.

Omalizumab. UpToDate Lexidrug, Lexi-Drugs Multinational Online. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 08/09/2025.

Omlyclo 150 mg/1 mL Solution for Injection in Pre-filled Syringe (Celltrion Healthcare Malaysia Sdn. Bhd.). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. https://www.npra.gov.my. Accessed 17/11/2025.

Omlyclo 75 mg Solution for Injection in Pre-filled Pen (Celltrion Healthcare United Kingdom Limited). MHRA. https://products.mhra.gov.uk. Accessed 17/11/2025.

Xolair 300 mg Solution for Injection in Pre-filled Syringe (Novartis Pharmaceuticals UK Limited). MHRA. https://products.mhra.gov.uk. Accessed 17/10/2025.

Xolair Injection, Solution (Genentech, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 09/09/2025.

Xolair Powder and Solvent for Solution for Injection (Novartis Corporation [Malaysia] Sdn. Bhd.). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. https://www.npra.gov.my. Accessed 09/09/2025.

Disclaimer: This information is independently developed by MIMS based on Omalizumab from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2025 MIMS. All rights reserved. Powered by MIMS.com