About This Tool

This Polivy (polatuzumab vedotin) Dosing Calculator provides a simple way for healthcare professionals to estimate the dose, volume for administration, and number of vials required for treatment. The calculations are based on the standard dosing regimen of 1.8 mg/kg as outlined in the prescribing information. This tool is intended for educational and informational purposes and should not replace clinical judgment.

Calculator Outputs Explained

After entering a patient’s weight, the calculator will provide the following key outputs:

• Total Dose to Administer (mg): This is the patient’s weight in kg multiplied by the standard dose of 1.8 mg/kg. The result is capped at a maximum of 180 mg per cycle, as per the prescribing information.
• Volume of Reconstituted Solution (mL): This is the total dose (in mg) divided by the final concentration of the reconstituted drug (20 mg/mL). It represents the volume to be withdrawn from the vial(s) for administration.
• Number of 140 mg Vials Required: This is a practical estimate of the minimum number of vials needed to prepare the dose. It is calculated by dividing the total dose by 140 mg (the amount per vial) and rounding up to the nearest whole number (ceiling function).

How to Use the Calculator

Using the calculator is straightforward and involves three simple steps:

1. Enter Patient Weight: Input the patient’s body weight into the designated field.
2. Select Units: Choose the appropriate unit of weight, either kilograms (kg) or pounds (lbs). The tool will automatically convert lbs to kg if selected.
3. Review Results: The calculated dose, volume, and vial count will be displayed instantly. There is no need to press a ‘calculate’ button after the initial calculation.

Dosing Overview for Polivy

Polivy is administered as an intravenous (IV) infusion. The standard dosing information is as follows:

• Recommended Dose: 1.8 mg/kg given every 21 days for 6 cycles in combination with bendamustine and a rituximab product.
• Maximum Dose: The total dose per cycle should not exceed 180 mg, regardless of the patient’s weight.
• Vial and Reconstitution: Polivy is supplied in a 140 mg single-dose vial. Each vial must be reconstituted with 7.2 mL of Sterile Water for Injection (SWFI) to achieve a final concentration of 20 mg/mL.

Dose Modifications

This calculator determines the initial dose and does not account for dose reductions or delays due to adverse reactions. Dose modifications for Polivy should be made in accordance with the official prescribing information. Reductions are typically recommended for managing peripheral neuropathy, myelosuppression (neutropenia, thrombocytopenia), and other toxicities. Always consult the latest guidelines before modifying a patient’s treatment regimen.

Missed Dose

If a planned dose of Polivy is missed, it should be administered as soon as possible. The administration schedule should then be adjusted to maintain a 21-day interval between subsequent doses. Do not wait until the next scheduled cycle to give the missed dose.

Important Safety Information

The use of Polivy is associated with several significant safety risks. This is not a complete list of all potential adverse events. Healthcare professionals must consult the full Prescribing Information for comprehensive safety data.

• Peripheral Neuropathy: New or worsening peripheral neuropathy is a common and important risk. Patients should be monitored for signs and symptoms such as sensory or motor changes.
• Infusion-Related Reactions: Polivy can cause infusion-related reactions. Patients should be premedicated and monitored during infusion.
• Myelosuppression: Grade 3-4 cytopenias, including neutropenia, thrombocytopenia, and anemia, can occur. Complete blood counts should be monitored throughout treatment.
• Progressive Multifocal Leukoencephalopathy (PML): Cases of PML have been reported. Clinicians should be alert for any new or worsening neurological signs or symptoms.

Frequently Asked Questions (FAQ)

What is the maximum dose of Polivy calculated by this tool?
The calculator caps the total dose at 180 mg per cycle, in line with the maximum recommended dose in the prescribing information.

How does the calculator determine the number of vials?
It divides the total required dose by 140 mg (the content of one vial) and rounds the result up to the next whole number to ensure enough drug is available for preparation.

Does this calculator account for dose adjustments for side effects?
No. This tool is for calculating the initial 1.8 mg/kg dose only. It does not provide recommendations for dose reductions due to toxicity or organ impairment.

What is the final concentration of Polivy after reconstitution?
The final concentration after reconstituting a 140 mg vial with 7.2 mL of SWFI is 20 mg/mL.

Is the 1.8 mg/kg dose used for all Polivy indications?
This dose is specified for use in combination with bendamustine and a rituximab product for adult patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL). Dosing for other indications or regimens may differ.

What weight conversion factor does the tool use?
The tool uses the conversion factor of 1 kg = 2.20462 lbs for calculations when pounds are selected.

Can I use this calculator for pediatric patients?
No. The safety and effectiveness of Polivy have not been established in pediatric patients. This tool is intended for adult patient dosing only.

Who should use this dosing tool?
This tool is designed for use by licensed healthcare professionals (physicians, pharmacists, nurses) and students as an educational resource to supplement, not replace, standard clinical practices and protocols.

References

• POLIVY® (polatuzumab vedotin-pii) US Prescribing Information. Genentech, Inc.
• Polivy (polatuzumab vedotin) European public assessment report (EPAR). European Medicines Agency.
• Polivy Official Healthcare Professional Website. Genentech, Inc.
• NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for B-Cell Lymphomas. National Comprehensive Cancer Network. (Login may be required).