Phesgo Dosage/Direction for Use

Patient Selection: Patients treated with Phesgo should have HER2-positive tumor status, defined as a score of 3+ by immunohistochemistry (IHC) or a ratio of ≥ 2.0 by in situ hybridization (ISH), assessed by a validated test.
To ensure accurate and reproducible results, the testing must be performed in a specialized laboratory, which can ensure validation of the testing procedures.
For full instructions on assay performance and interpretation, please refer to the package inserts of validated HER2 testing assays.
Administration of Phesgo: Phesgo therapy should only be administered under the supervision of a healthcare professional experienced in the treatment of cancer patients.
Substitution by any other biological medicinal product requires the consent of the prescribing physician.
In order to prevent medication errors, it is important to check the vial labels to ensure that the drug being prepared and administered is Phesgo.
Phesgo is for subcutaneous (SC) use in the thigh only. Do not administer intravenously.
Metastatic and Early Breast Cancer: For Phesgo dose recommendations in early and metastatic breast cancer refer to Table 7. (See Table 7.)

Click on icon to see table/diagram/image

The injection site should be alternated between the left and right thigh only. New injections should be given at least 1 inch/2.5 cm from the previous site on healthy skin and never into areas where the skin is red, bruised, tender, or hard. Do not split the dose between two syringes or between two sites of administration. During the treatment course with Phesgo, other medications for SC administration should preferably be injected at different sites.
In patients receiving a taxane, Phesgo should be administered prior to the taxane. When administered with Phesgo, the recommended initial dose of docetaxel is 75 mg/m2.
In patients receiving an anthracycline-based regimen, Phesgo should be administered following completion of the entire anthracycline regimen.
Early Breast Cancer (EBC): In the neoadjuvant setting (before surgery), it is recommended that patients are treated with Phesgo for three to six cycles depending on the regimen chosen in combination with chemotherapy (see Pharmacology: Pharmacodynamics: Clinical/efficacy studies under Actions).
In the adjuvant setting (after surgery), Phesgo should be administered for a total of one year (maximum 18 cycles or until disease recurrence, or unmanageable toxicity, whichever occurs first), as part of a complete regimen for early breast cancer, including standard anthracycline- and/or taxane-based chemotherapy. Phesgo treatment should start on Day 1 of the first taxane-containing cycle and should continue even if chemotherapy is discontinued (see Pharmacology: Pharmacodynamics: Clinical/efficacy studies under Actions).
Patients who start Phesgo in the neoadjuvant setting should continue to receive adjuvant Phesgo to complete 1 year of treatment (maximum 18 cycles).
Metastatic Breast Cancer (MBC): Phesgo should be administered in combination with docetaxel until disease progression or unmanageable toxicity. Treatment with Phesgo may continue even if treatment with docetaxel is discontinued.
Delayed or Missed Doses: If the time between two sequential doses is less than 6 weeks, the 600 mg pertuzumab/600 mg trastuzumab maintenance dose of Phesgo should be administered as soon as possible. Do not wait until the next planned dose.
If the time between two sequential injections is 6 weeks or more, the loading dose of 1200 mg pertuzumab/600 mg trastuzumab should be re-administered followed by the maintenance dose of 600 mg pertuzumab/600 mg trastuzumab every 3 weeks thereafter.
Dose Modifications: No dose reductions of Phesgo are recommended.
For chemotherapy dose modifications, see relevant prescribing information.
Injection-related reactions: The injection should be slowed or paused if the patient experiences injection-related symptoms (see Precautions).
Hypersensitivity/anaphylaxis: The injection should be discontinued immediately and permanently if the patient experiences a serious hypersensitivity reaction (e.g. anaphylaxis) (see Precautions).
Left ventricular dysfunction: See Precautions for information on dose recommendations in the event of left ventricular dysfunction.
SPECIAL DOSAGE INSTRUCTIONS: Pediatric use: The safety and efficacy of Phesgo in children and adolescents (<18 years) has not been established.
Geriatric use: No dose adjustment of Phesgo is required in patients ≥65 years of age (see Use in the Elderly under Precautions and Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations: Geriatric Population under Actions).
Renal Impairment: Dose adjustments of Phesgo are not needed in patients with mild or moderate renal impairment. No dose recommendations can be made for patients with severe renal impairment because of the limited pharmacokinetic data available (see Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations under Actions).
Hepatic Impairment: The safety and efficacy of Phesgo have not been studied in patients with hepatic impairment. No dose recommendation can be made for Phesgo (see Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations under Actions).