How to take Herzuma (trastuzumab-pkrb)

Patients will need to be treated with Herzuma (trastuzumab-pkrb) for a total of 52 weeks. It is not recommended to extend adjuvant therapy for more than one year. As a combination therapy, give an initial dose of 4 mg/kg as an intravenous infusion over 90 minutes during the first 12 weeks (paclitaxel or docetaxel) or 18 weeks (docetaxel and carboplatin) of chemotherapy, followed by 2 mg/kg as an intravenous infusion over 30 minutes weekly; and 6 mg/kg as an intravenous infusion over 30 to 90 minutes every three weeks during the week after the last weekly dose of Herzuma.

When used as a single agent in the adjuvant treatment of breast cancer within three weeks of completion of a multimodal anthracycline chemotherapy regimen, Herzuma is administered at an initial dose of 8 mg/kg as an intravenous infusion over 90 minutes, followed by subsequent doses of 6 mg/kg as an intravenous infusion over 30 to 90 minutes every three weeks. Herzuma is administered alone or in combination with paclitaxel to treat metastatic breast cancer (MBC) at an initial dose of 4 mg/kg as an intravenous infusion over 90 minutes, followed by 2 mg/kg as an intravenous infusion over 30 minutes once weekly until disease progression. Herzuma is used to treat metastatic gastric cancer (MGC) with an initial dose of 8 mg/kg as a 90-minute intravenous infusion, followed by 6 mg/kg as an intravenous infusion over 30-90 minutes every three weeks until disease progression.

If a patient misses a week or less of a dose of Herzuma, the regular maintenance dose (weekly schedule: 2 mg/kg; three-week schedule: 6 mg/kg) should be administered as soon as possible. Don’t wait until the next planning cycle. Subsequent Herzuma maintenance doses should be administered after 7 days or 21 days according to a weekly or three-week schedule, respectively. If a patient misses a dose of Herzuma by more than one week, a reloading dose of Herzuma (weekly schedule: 4 mg/kg; three-week schedule: 8 mg/kg) should be administered as soon as possible within approximately 90 minutes. Subsequent Herzuma maintenance doses (weekly regimen: 2 mg/kg; three-week regimen: 6 mg/kg) should be administered after 7 days or 21 days according to the weekly or three-week regimen, respectively.