About This Content

This information provides a supplementary overview of the Erelzi (etanercept-szzs) Dosing Calculator. It clarifies the tool's inputs, outputs, and the clinical data used for its calculations. This content is for educational purposes and should not replace clinical judgment or the full Prescribing Information.

Outputs

After providing the necessary inputs, the calculator generates a patient-specific dosing recommendation that includes:

• Calculated Dose: The precise dose in milligrams (mg).
• Dosing Frequency: How often the dose should be administered (e.g., once weekly).
• Administration Route: Specifies subcutaneous injection as the method of delivery.
• Formulation Guidance: Provides notes on which Erelzi® presentation (e.g., prefilled syringe, lyophilized powder) is appropriate for the calculated dose.

How to Use

To operate the calculator, follow these steps:

1. Select Indication: Choose the patient's condition from the dropdown menu (e.g., Rheumatoid Arthritis, Plaque Psoriasis).
2. Select Patient Population: Choose either 'Adult' or 'Pediatric'. The pediatric option is only available for the Polyarticular Juvenile Idiopathic Arthritis (JIA) indication, as per its FDA approval.
3. Enter Patient Weight: If calculating for a pediatric JIA patient, this field becomes active. Enter the patient's weight and select the units (kg or lbs).

Dosing Overview

The calculator's logic is based on the FDA-approved dosing schedules for Erelzi®.

Rheumatoid Arthritis (RA), Psoriatic Arthritis (PsA), & Ankylosing Spondylitis (AS)

For adult patients with these conditions, the standard maintenance dosing schedule is 50 mg administered once weekly via subcutaneous injection.

Plaque Psoriasis (PsO)

For adult patients, the dosing involves two phases:

• Initial Dose (Induction): 50 mg administered twice weekly for 3 months.
• Maintenance Dose: Following the initial phase, the dose is reduced to 50 mg administered once weekly.

Polyarticular Juvenile Idiopathic Arthritis (JIA)

For pediatric patients aged 2 years and older, dosing is weight-based:

• Weight-Based Dose: 0.8 mg/kg administered once weekly.
• Maximum Dose: The dose should not exceed 50 mg per week. For patients weighing 63 kg or more, the standard adult dose of 50 mg once weekly is recommended.

Switching

The decision to switch a patient to or from Erelzi® and another biologic agent should be made by a qualified healthcare provider. This process requires careful clinical consideration, including evaluation of the patient's disease activity, previous treatment responses, and potential for immunogenicity.

Missed Dose

If a patient misses a dose of Erelzi®, they should be advised to inject the missed dose as soon as they remember. They should then take their next dose at the regularly scheduled time. Patients should not inject two doses at the same time.

Safety Alerts

Etanercept products, including Erelzi®, have a Boxed Warning regarding serious infections and malignancies. Patients treated with TNF inhibitors are at increased risk for developing serious infections that may lead to hospitalization or death. Healthcare providers should monitor patients closely for signs and symptoms of infection during and after treatment. Always consult the full Prescribing Information for a complete list of warnings, precautions, and adverse events.

Frequently Asked Questions (FAQ)

Why is the pediatric option disabled for rheumatoid arthritis?

The calculator restricts the pediatric option to the Polyarticular Juvenile Idiopathic Arthritis (JIA) indication because this is the specific FDA-approved pediatric use for Erelzi®. Dosing for other indications in pediatric populations is not established.

What dose does the calculator recommend for a pediatric JIA patient weighing 70 kg?

For any pediatric JIA patient weighing 63 kg (approx. 138 lbs) or more, the calculator will recommend the maximum dose of 50 mg once weekly.

What formulation is recommended for a calculated dose of 20 mg?

For doses less than 50 mg, the calculator notes that the 25 mg lyophilized powder for reconstitution should be used. This allows for the precise withdrawal and administration of a specific, weight-based dose.

Does this calculator provide guidance for dose adjustments due to renal or hepatic impairment?

No, the calculator does not account for renal or hepatic impairment. Dosing in these populations has not been studied. Clinical judgment is required.

Is Erelzi administered via intravenous infusion?

No. As indicated by the calculator's output, Erelzi is administered only as a subcutaneous injection.

Can this tool be used to calculate doses for Enbrel®?

No. This calculator is specific to Erelzi® (etanercept-szzs), a biosimilar to Enbrel®. While they share the same active ingredient, always refer to the specific Prescribing Information for the product being used.

Does the calculator provide dosing for children under 2 years of age?

No. The calculator is intended for use in pediatric patients aged 2 years and older for the JIA indication, in line with the product's labeling. The safety and effectiveness in patients under 2 have not been established.

What is the initial dosing schedule for an adult with plaque psoriasis?

The calculator will output an initial (induction) dosing schedule of 50 mg twice weekly for the first 3 months, followed by a maintenance dose of 50 mg once weekly.