What is the recommended treatment regimen for an adult or adolescent patient with severe asthma or chronic spontaneous urticaria, who has a history of severe allergic reactions and has tried other treatments without adequate relief, using Xolair (omalizumab)?

Xolair (Omalizumab) Treatment Regimen

Recommended Dosing for Severe Asthma

For adults and adolescents ≥12 years with severe persistent allergic asthma inadequately controlled on high-dose inhaled corticosteroids plus long-acting beta agonists, administer Xolair 75-375 mg subcutaneously every 2 or 4 weeks based on baseline serum total IgE level (30-700 IU/mL) and body weight (30-150 kg). 1

Dosing Algorithm for Asthma

• Measure serum total IgE level before initiating treatment 1
• Use dosing tables to determine exact dose based on IgE level and body weight 1
• Typical doses range from 150-300 mg every 4 weeks, or 225-375 mg every 2 weeks 2, 3
• Do not re-test IgE levels during treatment, as they remain elevated for up to one year after discontinuation 1
• For treatment interruptions <1 year, use original IgE levels; for interruptions ≥1 year, re-test IgE 1

Position in Asthma Treatment Algorithm

• Consider omalizumab at Step 5 for patients with allergies on high-dose inhaled corticosteroids plus long-acting beta agonist 4
• At Step 6, add omalizumab to high-dose inhaled corticosteroids, long-acting beta agonist, and oral corticosteroids for patients with allergies 4
• Approximately 40% of patients can completely withdraw from inhaled corticosteroid therapy while maintaining asthma control on omalizumab 2, 3

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Recommended Dosing for Chronic Spontaneous Urticaria

For adults and adolescents ≥12 years with chronic spontaneous urticaria who remain symptomatic despite H1 antihistamine treatment, administer Xolair 300 mg subcutaneously every 4 weeks. 1

Key Differences from Asthma Dosing

• Dosing for chronic spontaneous urticaria is NOT dependent on serum IgE level or body weight 1
• The fixed dose is 300 mg every 4 weeks for all patients 1, 5
• The 75 mg and 150 mg doses did not demonstrate consistent efficacy and are not approved 1

Treatment Response Expectations

• At Week 12,36% of patients achieved complete symptom resolution (no itch, no hives) on 300 mg dose 1
• Significant improvements in weekly itch severity scores and hive counts occur within 12 weeks 1, 5
• The appropriate duration of therapy has not been determined; periodically reassess need for continued treatment 1

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Critical Safety Requirements: Anaphylaxis Risk

All patients receiving Xolair must be monitored for anaphylaxis, which occurs in approximately 0.2% of patients and can be life-threatening. 4, 1

Mandatory Observation Periods

• Observe for 2 hours after each of the first 3 injections 4, 6
• Observe for 30 minutes after all subsequent injections 4, 6, 1
• These observation periods would capture 75% of anaphylactic reactions 4

Administration Setting Requirements

• Administer only in healthcare settings with staff, equipment, and medications to treat anaphylaxis 4, 6, 1
• Healthcare providers must be trained to recognize and treat anaphylaxis 4
• Home administration is not appropriate 4

Patient Education and Epinephrine Requirements

• All patients must be prescribed an epinephrine autoinjector before starting treatment 4, 6
• Ensure the prescription is filled, not just written 4, 6
• Train patients in recognition of anaphylaxis signs/symptoms and proper autoinjector use 4, 6, 1
• Patients must carry the autoinjector and have it immediately available during and for 24 hours after each injection 6

Informed Consent

• Obtain and document informed consent discussing the 0.2% anaphylaxis risk before initiating therapy 4, 6
• Document this in the medical record or as a written consent form 4

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Common Pitfalls to Avoid

Dosing Errors

• Do not use IgE-based dosing for chronic spontaneous urticaria—the dose is always 300 mg every 4 weeks regardless of IgE or weight 1
• Do not use the 75 mg or 150 mg doses for chronic spontaneous urticaria, as they lack consistent efficacy 1
• Do not re-test IgE levels during treatment to adjust dosing, as levels remain artificially elevated 1

Safety Oversights

• Never skip the 2-hour observation period for the first 3 doses—61% of anaphylactic reactions occur within 2 hours of these early doses 4
• Do not assume patients are safe after the observation period; 25% of reactions occur later, necessitating the epinephrine autoinjector 4
• Do not merely write an epinephrine prescription—verify it is filled and provide hands-on training 4, 6

Treatment Algorithm Errors

• For asthma, do not use omalizumab before optimizing inhaled corticosteroids and long-acting beta agonists (Steps 5-6 only) 4
• For chronic spontaneous urticaria, ensure patients have failed standard-dose H1 antihistamines before initiating omalizumab 6, 1
• Consider updosing antihistamines to 4-fold standard dose before adding omalizumab for urticaria 6

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Tolerability Profile

• Common adverse events include injection site reactions, headache, upper respiratory tract infections, sinusitis, and pharyngitis 2, 5, 3
• The incidence and severity of adverse events with omalizumab are similar to placebo 2, 5, 3
• Most adverse events are mild to moderate in severity 5
• Omalizumab is generally well tolerated for treatment durations up to 52 weeks 2, 3, 7