What is Phesgo (pertuzumab, trastuzumab, and hyaluronidase) treatment in breast cancer?

From the Guidelines

Phesgo is a recommended treatment for HER2-positive breast cancer, containing pertuzumab, trastuzumab, and hyaluronidase, and is administered as a subcutaneous injection, offering a faster administration time and improved patient outcomes, as supported by recent guidelines and studies 1.

Key Points

• Phesgo is approved for both early and metastatic HER2-positive breast cancer and can be used in neoadjuvant settings (before surgery), adjuvant settings (after surgery), or for metastatic disease.
• The typical treatment schedule involves an initial loading dose followed by maintenance doses every three weeks.
• Common side effects include injection site reactions, hair loss, nausea, diarrhea, fatigue, and potential cardiac issues.
• Phesgo works by targeting the HER2 protein that is overexpressed in approximately 15-20% of breast cancers, with pertuzumab blocking HER2 dimerization, trastuzumab attaching to HER2 receptors to slow cancer growth, and hyaluronidase helping with drug absorption.
• Regular heart monitoring is required during treatment as these medications can affect heart function, as noted in studies such as 1 and guidelines like 1.

Administration and Efficacy

• Phesgo is administered as a subcutaneous injection, typically in the thigh, and offers a faster administration time (about 5-8 minutes) compared to traditional intravenous infusions of these medications which can take hours.
• The combination of pertuzumab and trastuzumab has been shown to improve overall survival and progression-free survival in patients with HER2-positive breast cancer, as demonstrated in studies like the CLEOPATRA trial 1.

Guidelines and Recommendations

• Recent guidelines, such as those from the American Society of Clinical Oncology (ASCO) 1 and the National Comprehensive Cancer Network (NCCN) 1, recommend Phesgo as a treatment option for HER2-positive breast cancer.
• These guidelines emphasize the importance of continuing HER2-targeted therapy until progression or unacceptable toxicity, and highlight the need for regular heart monitoring during treatment.

From the FDA Drug Label

PERJETA is a HER2/neu receptor antagonist indicated for: Use in combination with trastuzumab and docetaxel for treatment of patients with HER2-positive metastatic breast cancer (MBC) who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease. Phesgo is a fixed-dose combination of pertuzumab, trastuzumab, and hyaluronidase, administered via subcutaneous injection, for the treatment of patients with HER2-positive breast cancer.

Phesgo treatment in breast cancer is a combination of pertuzumab and trastuzumab, which are both HER2/neu receptor antagonists. It is used for the treatment of patients with HER2-positive breast cancer, including:

• Metastatic breast cancer (MBC): in combination with docetaxel, for patients who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease.
• Neoadjuvant treatment of breast cancer: in combination with chemotherapy, for patients with HER2-positive, locally advanced, inflammatory, or early stage breast cancer.
• Adjuvant treatment of breast cancer: in combination with trastuzumab and chemotherapy, for patients with HER2-positive early breast cancer at high risk of recurrence. 2 2

From the Research

Phesgo Treatment in Breast Cancer

• Phesgo is a fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection, approved by the FDA for the treatment of patients with HER2-positive early-stage and metastatic breast cancer 3.
• The treatment is administered in approximately 5-8 minutes, which is significantly less time than the traditional intravenous administration of pertuzumab and trastuzumab, which can take 1-2.5 hours 4.
• Studies have shown that Phesgo is non-inferior to intravenous pertuzumab plus trastuzumab in terms of pertuzumab and trastuzumab serum levels, with comparable total pathologic complete response rates and incidence of grade ≥3 and serious adverse events 4, 5.

Patient Preference and Satisfaction

• A phase II study found that 85% of patients preferred Phesgo over intravenous pertuzumab plus trastuzumab, citing reduced clinic time and comfort during administration as the main reasons for their preference 6.
• Patients who received Phesgo reported high satisfaction rates, with 88.1% of patients reporting that they were very satisfied or satisfied with the treatment 6.

Safety and Efficacy

• The FeDeriCa study, a randomized, open-label, multicenter, non-inferiority, phase 3 study, found that Phesgo had a similar safety profile to intravenous pertuzumab plus trastuzumab, with no new safety signals identified 5.
• The study also found that Phesgo provided non-inferior cycle 7 pertuzumab serum trough concentrations to intravenous pertuzumab plus trastuzumab, supporting the FDA approval of the treatment 5.