About this Tool
The Benralizumab Dose Calculator is a clinical support tool designed to determine the correct dosing schedule for benralizumab (Fasenra®) in patients with severe eosinophilic asthma. It calculates the appropriate dose based on patient age, weight (for pediatric patients), and the current phase of treatment—either the initial loading doses or subsequent maintenance doses.
Outputs
After entering the required patient data, the calculator provides the following key outputs:
- Recommended Dose: The precise dose in milligrams (mg), which is either 10 mg or 30 mg.
- Patient Group: Clarifies the patient category, such as "Adult/Adolescent" or "Pediatric" with the corresponding weight.
- Dosing Frequency: Specifies the administration interval, which is every 4 weeks for loading doses and every 8 weeks for maintenance doses.
- Next Dose Due: If the last dose date is provided, the tool calculates and displays the date when the next subcutaneous injection is scheduled.
How to Use
Follow these steps to determine the correct benralizumab dosing regimen:
- Enter Patient Age: Input the patient's age in years. The calculator will automatically show the weight field if the patient is between 6 and 11 years old.
- Enter Patient Weight: For pediatric patients (ages 6-11), enter their weight and select the unit (kg or lbs). This input is critical for dose determination in this age group.
- Select Dose Sequence: Choose between "Loading Dose" (for the first three doses) and "Maintenance Dose" (for the fourth dose and beyond).
- Enter Last Dose Date (Optional): To calculate the next administration date, input the date of the patient's last dose.
- Calculate: The tool will instantly display the recommended dosing information based on the provided inputs.
Dosing Overview
Benralizumab is administered as a subcutaneous injection. The dosing strategy is divided into an induction phase and a maintenance phase.
| Patient Population | Patient Weight | Loading Dose (First 3 Doses) | Maintenance Dose (4th Dose Onward) |
|---|---|---|---|
| Adults & Adolescents (≥12 years) | N/A | 30 mg every 4 weeks | 30 mg every 8 weeks |
| Pediatric (6 to 11 years) | ≥35 kg | 30 mg every 4 weeks | 30 mg every 8 weeks |
| <35 kg | 10 mg every 4 weeks | 10 mg every 8 weeks |
Switching
When switching a patient from another biologic therapy to benralizumab, clinicians should use their judgment and refer to the official prescribing information. The initiation of benralizumab typically follows the standard loading dose schedule, but the timing relative to the last dose of the previous biologic should be carefully considered.
Missed Dose
If a loading dose (every 4 weeks) is missed, the patient should receive it as soon as possible and then continue with their scheduled dosing. If a maintenance dose (every 8 weeks) is missed, the patient should receive the dose as soon as possible, and the next dose should be administered 8 weeks later. Do not administer a double dose to make up for a missed one.
Safety Alerts
Frequently Asked Questions
Why is patient weight required for children but not for adults?
The approved dosing for pediatric patients aged 6 to 11 is weight-based to ensure appropriate exposure. Patients under 35 kg receive a 10 mg dose, while those 35 kg or heavier receive the 30 mg dose. For patients aged 12 and older, a fixed 30 mg dose is used regardless of weight.
What is the difference between a "loading dose" and a "maintenance dose"?
The loading phase consists of the first three doses, administered every 4 weeks to quickly achieve therapeutic levels of the medication. The maintenance phase begins with the fourth dose, where the dosing interval is extended to every 8 weeks for long-term control.
How does the calculator determine the "Next Dose Due" date?
It adds the appropriate dosing interval (28 days for loading, 56 days for maintenance) to the "Date of Last Dose" that you provide.
Is the dose for a 12-year-old different from an adult?
No. According to the prescribing information, patients aged 12 years and older follow the adult dosing regimen: 30 mg, regardless of weight.
Can I use this calculator for a child younger than 6 years old?
No. The safety and efficacy of benralizumab have not been established in patients under 6 years of age. The tool will show an error for ages below this threshold.
What happens if a child's weight increases from under 35 kg to over 35 kg during treatment?
The prescribing clinician should adjust the dose from 10 mg to 30 mg at the next scheduled administration. Always consult the official product label for guidance on dose adjustments.
Is the dose adjusted for renal or hepatic impairment?
No dose adjustment is necessary for patients with renal or hepatic impairment. This tool does not account for specific comorbidities; clinical judgment is paramount.
How should benralizumab be administered?
It is administered via subcutaneous injection into the thigh, abdomen, or upper arm. It is available as a pre-filled syringe or autoinjector for administration by a healthcare professional or for patient self-administration after proper training.
References
- FASENRA® (benralizumab) Prescribing Information. U.S. Food and Drug Administration. Available at: www.accessdata.fda.gov
- Fasenra (benralizumab) Summary of Product Characteristics (SmPC). European Medicines Agency. Available at: www.ema.europa.eu
- FASENRA® Official HCP Site. AstraZeneca. Available at: www.fasenrahcp.com
- Goldman M, Hirsch I, Zangrilli JG. A review of the clinical development of benralizumab for the treatment of severe asthma. Ther Adv Respir Dis. 2020;14:1753466620977209. doi:10.1177/1753466620977209. Available at: www.ncbi.nlm.nih.gov
