About this Content

This information provides a supplementary guide to the Tecentriq (atezolizumab) Dosing Calculator. It outlines the tool’s functions, the data it presents, and key clinical considerations based on the Prescribing Information. Always use this tool in conjunction with independent clinical judgment.

Outputs

After entering the required patient and treatment parameters, the calculator provides a comprehensive dosing summary, which includes:

• Recommended Dose: The specific flat dose in milligrams (e.g., 840 mg, 1200 mg, or 1680 mg).
• Vial Preparation: The number and size of Tecentriq vials required to prepare the dose.
• Volume to Withdraw: The total volume in milliliters (mL) to be withdrawn from the vials.
• Administration and Infusion: Standard instructions for diluting the drug and the recommended infusion time (60 minutes for the initial dose, 30 minutes for subsequent infusions if tolerated).
• Next Dose Calculator: A feature to determine the due date for the next infusion based on the selected dosing interval.

How to Use

The calculator is designed for ease of use by healthcare professionals. Follow these simple steps:

1. Select Indication: Choose the appropriate FDA-approved indication from the dropdown menu. This will determine the available dosing regimens.
2. Enter Patient Weight: Input the patient’s weight and select the unit (kg or lbs). While Tecentriq is a flat-dose medication, weight is required to ensure the patient is within a safe and clinically appropriate range.
3. Select Dosing Regimen: Based on the indication, choose the desired administration schedule (e.g., every 2, 3, or 4 weeks).
4. Calculate and Review: Click the “Calculate Dose” button to generate the complete dosing and administration summary.

Dosing Overview

Tecentriq is administered as a fixed, or “flat,” dose. The dosage does not change based on patient weight. The approved adult dosing regimens, which depend on the indication, are:

• 840 mg every 2 weeks
• 1200 mg every 3 weeks
• 1680 mg every 4 weeks

The drug is supplied in single-dose vials of two strengths: 840 mg/14 mL and 1200 mg/20 mL. The calculator automatically determines the correct vial combination to achieve the target dose.

Switching Dosing Schedules

Per the Prescribing Information, patients receiving the 1200 mg every 3 weeks regimen may be switched to 1680 mg every 4 weeks. This decision should be based on clinical judgment and treatment goals. The calculator allows for the selection of any approved regimen for a given indication, facilitating planning for such a switch.

Missed Dose

If a planned dose of Tecentriq is missed, it should be administered as soon as possible. The administration schedule should then be adjusted to maintain the correct interval between doses. Do not wait until the next planned cycle to administer the missed dose. Consult the full Prescribing Information for detailed guidance.

Safety Alerts and Dose Modifications

The calculator includes a separate module to provide guidance on dose modifications for immune-mediated adverse reactions. Based on the type and grade (per CTCAE) of the reaction, the tool outlines whether Tecentriq should be withheld or permanently discontinued. Key adverse reactions covered include:

• Immune-mediated pneumonitis
• Immune-mediated colitis or diarrhea
• Immune-mediated hepatitis
• Immune-mediated endocrinopathies (e.g., thyroid disorders, adrenal insufficiency, type 1 diabetes)
• Immune-mediated nephritis with renal dysfunction
• Severe skin adverse reactions (SJS, TEN)
• Immune-mediated myocarditis

FAQ

Is the dose of Tecentriq calculated based on patient weight?

No, Tecentriq is administered as a flat dose. The calculator requests patient weight to validate that it falls within a typical clinical range (20-300 kg) but does not use it to calculate the actual milligram dose.

What are the available vial sizes for Tecentriq?

Tecentriq is available in two single-dose vial sizes: 1200 mg in 20 mL and 840 mg in 14 mL. Both have a concentration of 60 mg/mL.

Can I use this calculator for pediatric patients?

No, this calculator is based on the adult dosing regimens specified in the FDA Prescribing Information. The safety and effectiveness of Tecentriq in pediatric patients have not been established for all indications.

How does the calculator determine the next dose date?

Once you input a start date for the infusion, the tool adds the number of days corresponding to the selected regimen (e.g., 21 days for a 3-week cycle) to calculate the next due date.

Does the tool account for dose reductions?

No, dose reductions are not recommended for Tecentriq. Dosing is managed by either delaying (withholding) a dose or permanently discontinuing treatment in response to adverse reactions, as guided by the tool’s “Dose Modification” section.

Which indications are included in the calculator?

The calculator includes dosing regimens for FDA-approved indications such as Non-Small Cell Lung Cancer (NSCLC), Small Cell Lung Cancer (SCLC), Hepatocellular Carcinoma (HCC), Melanoma, Urothelial Carcinoma (UC), and Triple-Negative Breast Cancer (TNBC).

What information is copied when I use the “Copy Summary” feature?

The feature copies a plain-text summary of the dosing plan, including the indication, patient weight, and all administration details (dose, vial prep, infusion instructions). If a date is entered, it also includes the administration date and the next due date.

Is this calculator a substitute for the official Prescribing Information?

Absolutely not. This tool is for informational and educational support only. It is not a substitute for clinical judgment or the official, most current FDA Prescribing Information, which should always be consulted as the primary source of truth.

References

1. [1] Tecentriq (atezolizumab) Prescribing Information. Genentech, Inc. South San Francisco, CA. View PDF
2. [2] U.S. Food and Drug Administration. Drugs@FDA: FDA-Approved Drugs. Tecentriq (atezolizumab). View Source
3. [3] Genentech. Tecentriq HCP Official Site. Visit Website
4. [4] National Cancer Institute. Atezolizumab. View Source