FDA approved Phesgo (pertuzumab, trastuzumab, hyaluronidase) for HER2-Positive Breast CancerFDA approved new shot for HER2 positive breast cancer treatment

Phesgo is a combination of pertuzumab and trastuzumab, both HER2/neu receptor antagonists, and hyaluronidase, an endoglycosidase. Pertuzumab and trastuzumab bind to different epitopes of the HER2 receptor, inhibiting downstream signaling and mediating antibody-dependent cell-mediated cytotoxicity. Hyaluronidase increases permeability of subcutaneous tissue by temporarily depolymerizing hyaluronan, facilitating drug absorption.

Phesgo is indicated for use in combination with chemotherapy for: - Neoadjuvant treatment of adult patients with HER2-positive, locally advanced, inflammatory, or early stage breast cancer (either >2 cm in diameter or node positive) as part of a complete treatment regimen for early breast cancer. - Adjuvant treatment of adult patients with HER2-positive early breast cancer at high risk of recurrence. - Treatment of adult patients with HER2-positive metastatic breast cancer (MBC) who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease, in combination with docetaxel. Select patients based on HER2 protein overexpression or gene amplification using an FDA-approved companion diagnostic test.

For subcutaneous use in the thigh only. Do not administer intravenously. The initial dose is 1,200 mg pertuzumab, 600 mg trastuzumab, and 30,000 units hyaluronidase in 15 mL administered over approximately 8 minutes. Maintenance doses (every 3 weeks) are 600 mg pertuzumab, 600 mg trastuzumab, and 20,000 units hyaluronidase in 10 mL administered over approximately 5 minutes. No dose adjustments for body weight or concomitant chemotherapy. For EBC, administer with chemotherapy preoperatively for 3-6 cycles (neoadjuvant) or postoperatively for up to 1 year (adjuvant). For MBC, administer with docetaxel every 3 weeks. Observe patients for 30 minutes after initial dose and 15 minutes after maintenance doses for hypersensitivity or administration-related reactions.

Trial data not available in label.

Not reported in label.

Phesgo provides a subcutaneous fixed-dose combination of pertuzumab and trastuzumab, offering an alternative to intravenous administration. It is indicated for HER2-positive early breast cancer (neoadjuvant and adjuvant) and metastatic breast cancer in combination with chemotherapy. It should not be substituted for or with intravenous pertuzumab, intravenous trastuzumab, ado-trastuzumab emtansine, or fam-trastuzumab deruxtecan.