How are Phesgo (pertuzumab, trastuzumab, and hyaluronidase) and docetaxel administered?

Administration of Phesgo and Docetaxel

Phesgo (pertuzumab, trastuzumab, and hyaluronidase) is administered subcutaneously over approximately 2-5 minutes at a fixed dose of 600 mg pertuzumab/600 mg trastuzumab/10,000 units hyaluronidase every 3 weeks, while docetaxel is administered intravenously at 75 mg/m² (with potential escalation to 100 mg/m² if tolerated) every 3 weeks. 1

Phesgo Administration

• Initial dose: 600 mg pertuzumab/600 mg trastuzumab/10,000 units hyaluronidase administered subcutaneously
• Subsequent doses: Same fixed dose (600 mg/600 mg/10,000 units) every 3 weeks
• Administration time: Approximately 2-5 minutes
• Administration site: Subcutaneous injection in the thigh

Docetaxel Administration

• Initial dose: 75 mg/m² intravenously on day 1 of each cycle
• Subsequent doses: May be escalated to 100 mg/m² if initial dose is well tolerated
• Administration time: Intravenous infusion over 1 hour
• Cycle length: Every 21 days (3 weeks)
• Duration: Typically 6 cycles, but may be continued longer at physician discretion

Sequencing of Administration

1. Phesgo (subcutaneous)
2. Docetaxel (intravenous)

Important Considerations

• An observation period of 30-60 minutes is recommended after the first Phesgo administration and before docetaxel administration 1
• In patients receiving an anthracycline-based regimen, Phesgo should be administered following completion of the anthracycline component 1
• Docetaxel dose reductions may be necessary based on individual patient tolerance, particularly in Asian populations where higher rates of adverse events have been observed 2
• Cardiac monitoring is required at baseline, 3,6, and 9 months during treatment 3

Duration of Therapy

• For early breast cancer: Phesgo is continued for a total of 1 year (up to 18 cycles) or until disease recurrence or unmanageable toxicity 1
• For metastatic breast cancer: Phesgo is continued until disease progression or unmanageable toxicity 4
• Docetaxel is typically administered for 6 cycles but may be continued longer at physician discretion 5

Dose Modifications

• If a dose of Phesgo is missed and the time between two sequential doses is <6 weeks, administer the maintenance dose of 600 mg/600 mg/10,000 units as soon as possible 1
• If the time between doses is ≥6 weeks, readminister the loading dose 1
• Docetaxel dose reductions below 75 mg/m² may be necessary to manage toxicities 2

This administration approach has demonstrated significant improvements in progression-free and overall survival in HER2-positive breast cancer patients without significantly increasing cardiac toxicity compared to other regimens 4, 6.