What is the dosing schedule and administration method for the Fasenra (benralizumab) subcutaneous autoinjector pen in a patient with severe eosinophilic asthma uncontrolled on high‑dose inhaled corticosteroids plus a long‑acting beta‑2 agonist?

Fasenra Pen Dosing and Administration for Severe Eosinophilic Asthma

For adults and adolescents 12 years and older with severe eosinophilic asthma uncontrolled on high-dose inhaled corticosteroids plus long-acting beta-2 agonists, administer Fasenra (benralizumab) 30 mg subcutaneously every 4 weeks for the first 3 doses, then every 8 weeks thereafter using the autoinjector pen. 1

Dosing Schedule

Standard Adult/Adolescent Regimen (≥12 years)

• Loading phase: 30 mg subcutaneous injection every 4 weeks for 3 doses (at weeks 0,4, and 8) 1
• Maintenance phase: 30 mg subcutaneous injection every 8 weeks starting at week 16 and continuing thereafter 1

Pediatric Patients (6-11 years)

• Weight <35 kg: 10 mg every 4 weeks for 3 doses, then every 8 weeks 1
• Weight ≥35 kg: 30 mg every 4 weeks for 3 doses, then every 8 weeks 1
• Important caveat: For children 6-11 years weighing ≥35 kg, the Fasenra Pen should only be administered by a caregiver or healthcare provider, not by the child 1

Administration Method with Fasenra Pen

Preparation Steps

• Remove the carton from refrigeration and allow it to warm to room temperature for approximately 30 minutes before injection 1
• Visually inspect the solution—it should be clear to opalescent, colorless to slightly yellow, and may contain a few translucent or white to off-white particles 1
• Do not use if the liquid is cloudy, discolored, or contains large particles or foreign particulate matter 1

Injection Sites and Technique

• Administer into the thigh or abdomen as preferred sites 1
• The upper arm can be used if a healthcare provider or caregiver administers the injection 1
• The autoinjector (Fasenra Pen) is designed for patient/caregiver self-administration after proper training in subcutaneous injection technique 1

Clinical Context and Monitoring

• Fasenra is intended for use under the guidance of a healthcare provider, with monitoring after administration recommended in line with clinical practice for biologic agents 1
• The first 3 doses are typically administered at the study site or clinic to ensure proper technique and monitor for adverse reactions 2
• Home administration can begin after the patient/caregiver demonstrates competency with the device 2

Expected Clinical Response Timeline

Rapid Onset of Action

• Clinical improvements can occur after the first dose, with striking changes typically observed after the second and third doses 3
• Blood eosinophil depletion is nearly complete by the end of the loading phase 2, 3
• Asthma control scores and lung function improvements are evident within the first 8-16 weeks 3

Long-Term Efficacy

• At least 75% of patients with blood eosinophils ≥300 cells/μL achieve zero exacerbations annually during maintenance therapy 4
• Benralizumab remains safe and well-tolerated for up to 5 years of continuous treatment, with no increase in adverse event rates over time 4

Device Reliability and Safety

Autoinjector Performance

• The Fasenra Pen demonstrates exceptional reliability, with 99-100% successful administration rates in both clinic and home settings 2
• Device malfunction is extremely rare (1 in 573 dispensed devices in clinical studies) 2
• Patient-use errors are uncommon, occurring in only 2 of 573 administrations 2

Common Adverse Events

• Most frequent adverse events include nasopharyngitis, upper respiratory tract infection, headache, and sinusitis 2
• Injection-site reactions are transient and mild to moderate, occurring in approximately 4% of patients 2
• Serious adverse event rates remain low and stable (6.3-8.4 per 100 patient-years) with long-term use 4

Clinical Pearls and Common Pitfalls

Patient Selection

• Benralizumab is effective regardless of serum IgE concentrations or atopy status, making it suitable for patients who may not qualify for omalizumab 5
• Patients with blood eosinophils ≥300 cells/μL at baseline demonstrate the most robust response, with 42-46% reductions in exacerbation rates 5

Avoiding Treatment Errors

• Do not expel air bubbles from the syringe prior to administration—small air bubbles are normal and do not affect dosing 1
• Ensure the entire plunger is depressed until the plunger head is completely between the needle guard activation clips to activate the safety mechanism 1
• Never remove the needle cover until immediately ready to inject, as premature removal may lead to contamination 1

Transitioning to Home Administration

• After demonstrating competency with the first 2-3 clinic-administered doses, patients/caregivers can safely transition to home administration 2
• The device performs equally well in home and clinic settings, with no difference in success rates 2