Overview
11 DESCRIPTION PHESGO is a combination of pertuzumab, trastuzumab, and hyaluronidase. Pertuzumab is a recombinant humanized monoclonal antibody that targets the extracellular dimerization domain (Subdomain II) of the human epidermal growth factor receptor 2 protein (HER2). Pertuzumab is produced by recombinant DNA technology in a mammalian cell (Chinese Hamster Ovary) culture.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Pertuzumab targets the extracellular dimerization domain (subdomain II) of HER2 and, thereby, blocks ligand-dependent heterodimerization of HER2 with other HER family members, including EGFR, HER3 and HER4. As a result, pertuzumab inhibits ligand-initiated intracellular signaling through two major signaling pathways, mitogen-activated protein (MAP) kinase and phosphoinositide 3-kinase (PI3K). Inhibition of these signaling pathways can result in cell growth arrest and apoptosis, respectively. Trastuzumab binds to subdomain IV of the extracellular domain of the HER2 protein to inhibit the ligand-independent, HER2 mediated cell proliferation and PI3K signaling pathway in human tumor cells that overexpress HER2.
Indications
- 1 INDICATIONS AND USAGE PHESGO is a combination of pertuzumab and trastuzumab, HER2/neu receptor antagonists, and hyaluronidase, an endoglycosidase, indicated for: Use in combination with chemotherapy as: neoadjuvant treatment of patients with HER2-positive, locally advanced, inflammatory, or early stage breast cancer (either greater than 2 cm in diameter or node positive) as part of a complete treatment regimen for early breast cancer. ( 1.1 ) adjuvant treatment of patients with HER2-positive early breast cancer at high risk of recurrence ( 1.
Common Doses
- 200 mg
- 600 mg
- 15 mL
- 10 mL
Dosage
2 DOSAGE AND ADMINISTRATION For subcutaneous use in the thigh only. ( 2.2 ) PHESGO has different dosage and administration instructions than intravenous pertuzumab and trastuzumab products. ( 2.2 ) Do not administer intravenously. ( 2.2 ) Perform HER2 testing using FDA-authorized tests by laboratories with demonstrated proficiency. ( 1 , 2.1 ) The initial dose of PHESGO is 1,200 mg pertuzumab, 600 mg trastuzumab, and 30,000 units hyaluronidase administered subcutaneously over approximately 8 minutes, followed every 3 weeks by a dose of 600 mg pertuzumab, 600 mg trastuzumab, and 20,000 units...
Black Box Warning
WARNING: CARDIOMYOPATHY, EMBRYO-FETAL TOXICITY, and PULMONARY TOXICITY WARNING: CARDIOMYOPATHY, EMBRYO-FETAL TOXICITY, and PULMONARY TOXICITY See full prescribing information for complete boxed warning. Cardiomyopathy: PHESGO administration can result in subclinical and clinical cardiac failure manifesting as CHF, and decreased LVEF, with greatest risk when administered concurrently with anthracyclines. Evaluate cardiac function prior to and during treatment. Discontinue PHESGO for cardiomyopathy. ( 2.3 , 5.
Contraindications
- 4 CONTRAINDICATIONS PHESGO is contraindicated in patients with known hypersensitivity to pertuzumab, or trastuzumab, or hyaluronidase, or to any of its excipients. PHESGO is contraindicated in patients with known hypersensitivity to pertuzumab, or trastuzumab, or hyaluronidase, or to any of its excipients. ( 4 )
Side Effects
- 6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the label: Cardiomyopathy [see Warnings and Precautions (5.1) ] Embryo-Fetal Toxicity [see Warnings and Precautions (5.2) ] Pulmonary Toxicity [see Warnings and Precautions (5.3) ] Exacerbation of Chemotherapy-Induced Neutropenia [see Warnings and Precautions (5.4) ] Hypersensitivity and Administration-Related Reactions [see Warnings and Precautions (5.
Interactions
- 7 DRUG INTERACTIONS Patients who receive anthracycline after stopping PHESGO may be at increased risk of cardiac dysfunction because of PHESGO's long washout period [see Clinical Pharmacology (12.3) ] . If possible, avoid anthracycline-based therapy for up to 7 months after stopping PHESGO. If anthracyclines are used, carefully monitor the patient's cardiac function.