What is the recommended dose, frequency, and route of administration for Benralizumab (anti-interleukin-5 receptor alpha subunit monoclonal antibody) in patients with severe asthma or hypereosinophilic syndrome?

Benralizumab Administration: Dose, Frequency, and Route

Benralizumab is administered subcutaneously at 30 mg every 4 weeks for the first 3 doses, then every 8 weeks thereafter. 1, 2, 3

Standard Dosing Regimen

The FDA-approved dosing schedule is:

• Initial loading phase: 30 mg subcutaneously every 4 weeks for the first 3 doses 3
• Maintenance phase: 30 mg subcutaneously every 8 weeks thereafter 3

This dosing regimen applies to both severe eosinophilic asthma and eosinophilic granulomatosis with polyangiitis (EGPA) in adults. 1, 3

Route of Administration

Benralizumab is given exclusively by subcutaneous injection. 3 The medication is available in two formulations:

• Single-dose prefilled syringe (30 mg in 1 mL) 3
• Single-dose autoinjector (30 mg in 1 mL) 3

Both contain a 29-gauge, ½-inch stainless steel needle for subcutaneous delivery. 3

Pediatric Dosing Considerations

For children aged 6-11 years with severe asthma, weight-based dosing may be considered, though the standard 30 mg dose has been studied in this population. 3 The pharmacodynamic effects (eosinophil reduction) were similar to those observed in adults and adolescents. 3

Onset of Action

Blood eosinophil depletion occurs remarkably fast:

• Eosinophil reduction is detectable within 24 hours of the first dose 3
• Median blood eosinophil counts reach 0 cells/μL by 4 weeks and remain suppressed throughout treatment 3, 4
• Clinical improvements in asthma control, lung function, and symptoms can be observed as early as 4 weeks after the first injection 4

Clinical Monitoring

The European Respiratory Society recommends therapeutic drug monitoring when using benralizumab, though specific parameters are not detailed in standard protocols. 1, 2

Important Practical Considerations

Key points for administration:

• The every-8-week maintenance dosing (after initial loading) distinguishes benralizumab from other anti-IL-5 therapies like mepolizumab, which requires monthly dosing 5
• The medication should appear clear to opalescent, colorless to slightly yellow; a few translucent or white particles may be present and are acceptable 3
• No dose adjustments are required based on age, weight, or disease severity in adults 3
• Unlike conventional immunosuppressants, benralizumab does not require pre-treatment tuberculin testing, chest radiographs, or hepatitis serology screening 2

Efficacy by Dosing Schedule

In clinical trials, both the every-4-week and every-8-week maintenance regimens (after initial loading) demonstrated similar efficacy in reducing exacerbations and improving lung function. 6, 7 The every-8-week schedule was selected as the standard maintenance regimen for patient convenience without compromising efficacy. 3