About This Tool

The Tremfya (guselkumab) Dosing Calculator is a support tool designed for U.S. healthcare professionals to map out the FDA-approved dosing schedule for patients. It provides a clear timeline for both induction and maintenance phases based on the selected indication and, where applicable, patient weight. This tool serves as a supplementary resource and is not intended to replace clinical judgment.

Outputs

After entering the required patient information, the calculator generates a detailed, printable dosing schedule for the first year of therapy. Key outputs include:

• Dose Number: The sequence of each administration (e.g., Dose 1, Dose 2).
• Treatment Week: The corresponding week of treatment (e.g., Week 0, Week 4).
• Calculated Date: The specific date for each administration based on the entered start date.
• Dosage & Route: The exact dose in milligrams (mg) and the method of administration (subcutaneous or intravenous).

How to Use

Using the calculator involves three simple steps:

1. Select Indication: Choose the relevant FDA-approved indication from the dropdown menu (Plaque Psoriasis, Psoriatic Arthritis, or Ulcerative Colitis).
2. Enter Patient Details: If Ulcerative Colitis is selected, the patient’s weight is required to calculate the correct intravenous induction dose. For other indications, this field is not needed. Select the date of the first planned administration.
3. Calculate Schedule: Click the “Calculate Schedule” button to generate the complete dosing timeline. The “Reset” button clears all fields to start over.

Dosing Overview

Plaque Psoriasis (PsO) & Psoriatic Arthritis (PsA)

The dosing for adult patients with moderate-to-severe plaque psoriasis or active psoriatic arthritis follows a subcutaneous (SC) injection schedule:

• Induction Doses: 100 mg SC at Week 0 and Week 4.
• Maintenance Doses: 100 mg SC every 8 weeks thereafter.

Ulcerative Colitis (UC)

The dosing for adult patients with moderately to severely active ulcerative colitis begins with a weight-based intravenous (IV) infusion for induction, followed by subcutaneous injections for maintenance:

• Induction Dose (Week 0): A single IV infusion based on body weight:
  • Less than 55 kg: 200 mg
  • 55 kg to 90 kg: 300 mg
  • More than 90 kg: 400 mg
• Maintenance Doses: 100 mg SC at Week 8, and every 8 weeks thereafter.

Switching

The decision to switch a patient to Tremfya from another biologic or systemic therapy should be based on careful clinical evaluation. This calculator does not provide guidance on washout periods or transition strategies. Please consult the full prescribing information and relevant clinical guidelines when considering a switch in therapy.

Missed Dose

According to the prescribing information, if a dose is missed, it should be administered as soon as possible. Afterward, the patient should resume their regularly scheduled dosing interval. This calculator does not adjust schedules for missed doses; any modifications should be managed by the treating clinician.

Safety Alerts

This tool does not contain a full safety profile of Tremfya (guselkumab). Healthcare professionals must consult the full U.S. Prescribing Information for complete details on contraindications, warnings and precautions (including risk of infections and pre-treatment evaluation for tuberculosis), adverse reactions, and drug interactions before initiating treatment.

Frequently Asked Questions

Why is patient weight required for the Ulcerative Colitis indication?

For Ulcerative Colitis, the initial induction dose is administered intravenously and is weight-based to ensure appropriate drug exposure. The calculator uses the patient’s weight to determine the correct IV dose (200 mg, 300 mg, or 400 mg).

What is the maintenance dosing schedule after the first year?

The dosing schedule shown in the calculator covers the first year of treatment. For all indications, the maintenance schedule of 100 mg administered subcutaneously every 8 weeks continues for as long as prescribed.

Is the dosing for Psoriatic Arthritis different from Plaque Psoriasis?

No, based on the U.S. Prescribing Information, the dosing regimen of 100 mg SC at Weeks 0, 4, and every 8 weeks thereafter is the same for both adult Plaque Psoriasis and Psoriatic Arthritis.

How are the administration dates determined?

The calculator automatically adds the required number of weeks for each interval (e.g., 4 weeks, 8 weeks) to the “First Dose Date” you provide to project the full schedule.

Can I use this calculator for pediatric patients?

This calculator is based on the dosing for adults as specified in the FDA label. It should not be used for pediatric patients unless their dosing aligns with the approved adult regimens.

What is the difference between an intravenous and a subcutaneous dose?

An intravenous (IV) dose is administered as an infusion directly into a vein, typically in a clinical setting. A subcutaneous (SC) dose is an injection given into the tissue just under the skin.

Does this tool account for loading doses?

Yes, the schedule for PsO/PsA includes the initial “loading” or induction doses at Week 0 and Week 4 before transitioning to the every-8-week maintenance schedule. For UC, it includes the single IV induction dose at Week 0.

Does the tool confirm medication supply or availability?

No, this is strictly a dosing schedule calculator. It does not track inventory, provide prescribing information, or connect with specialty pharmacies.

References

• 1. TREMFYA® (guselkumab) Prescribing Information. Janssen Biotech, Inc.
• 2. TREMFYA® HCP Website. Janssen Immunology.
• 3. U.S. Food and Drug Administration. Drugs@FDA Database: Tremfya. FDA.gov.