Last reviewed 2026-04-20 · How we verify

Perjeta (pertuzumab)

Pertuzumab targets the extracellular dimerization domain of the HER2 protein, blocking ligand-dependent heterodimerization with other HER family members.

Perjeta is a monoclonal antibody used to treat HER2-positive breast, colon, and rectal cancers. It works by blocking the HER2 protein, which can help slow or stop the growth of cancer cells. Perjeta is often used in combination with other medications, such as trastuzumab and docetaxel. This combination has been shown to be effective in treating metastatic HER2-positive breast cancer. In early HER2-positive breast cancer, Perjeta is used as a neoadjuvant to help shrink tumors before surgery. Perjeta is marketed by Pfizer Inc. and has a significant commercial presence in the oncology market.

At a glance

Mechanism of action

Pertuzumab works by binding to the extracellular dimerization domain of the HER2 protein. This binding blocks the interaction between HER2 and other HER family members, such as EGFR, HER3, and HER4. By inhibiting these interactions, pertuzumab prevents the activation of downstream signaling pathways, including the MAP kinase and PI3K pathways. This can lead to cell growth arrest and apoptosis, ultimately slowing or stopping the growth of cancer cells.

Approved indications

• HER2-positive carcinoma of breast
• HER2-positive colon cancer
• HER2-positive rectal cancer

Boxed warnings

• WARNING: LEFT VENTRICULAR DYSFUNCTION and EMBRYO-FETAL TOXICITY Left Ventricular Dysfunction: PERJETA can cause subclinical and clinical cardiac failure manifesting as decreased LVEF and CHF. Evaluate cardiac function prior to and during treatment. Discontinue PERJETA treatment for a confirmed clinically significant decrease in left ventricular function [see Dosage and Administration (2.3) , Warnings and Precautions (5.1) and Adverse Reactions (6.1) ]. Embryo-fetal Toxicity: Exposure to PERJETA can cause embryo-fetal death and birth defects. Advise patients of these risks and the need for effective contraception [see Warnings and Precautions (5.2) and Use in Specific Populations (8.1) (8.3) ]. WARNING: LEFT VENTRICULAR DYSFUNCTION and EMBRYO-FETAL TOXICITY See full prescribing information for complete boxed warning. Left Ventricular Dysfunction: PERJETA can cause subclinical and clinical cardiac failure manifesting as decreased LVEF and CHF. Evaluate cardiac function prior to and during treatment. Discontinue PERJETA treatment for a confirmed clinically significant decrease in left ventricular function. ( 2.3 , 5.1 , 6.1 ) Embryo-fetal Toxicity: Exposure to PERJETA can cause embryo-fetal death and birth defects. Advise patients of these risks and the need for effective contraception. ( 5.2 , 8.1 , 8.3 )

Common side effects

• Diarrhea
• Nausea
• Vomiting
• Alopecia
• Neutropenia
• Fatigue
• Rash
• Peripheral neuropathy
• Anemia
• Leukopenia
• Asthenia
• Mucosal inflammation

Drug interactions

• Trastuzumab
• Trastuzumab emtansine
• Capecitabine
• Docetaxel
• Paclitaxel
• Trastuzumab and Vinorelbine
• Trastuzumab and Epirubicin
• Trastuzumab and Cyclophosphamide
• Trastuzumab and Doxorubicin
• Trastuzumab and Mitomycin
• Trastuzumab and Vinblastine
• Trastuzumab and Irinotecan

Key clinical trials

• HER2 Directed Dendritic Cell Vaccine During Neoadjuvant Therapy of HER2+Breast Cancer (EARLY_PHASE1)
• Canadian Profiling and Targeted Agent Utilization Trial (CAPTUR) (PHASE2)
• Trastuzumab Deruxtecan in First-Line HER2-Positive Metastatic Breast Cancer With Proactive Toxicity Management (PHASE2)
• A Phase I Study to Compare the Pharmacokinetic Characteristics, Safety, and Immunogenicity of HLX319 and EU-Phesgo®. (PHASE1)
• Testing the Addition of Herceptin Hylecta or Phesgo to the Usual Chemotherapy for HER2 Positive Endometrial Serous Carcinoma or Carcinosarcoma (PHASE3)
• A Clinical Study of Neoadjuvant Treatment With TQB2102 for Injection for Human Epidermal Growth Factor Receptor 2 (HER2) Positive Breast Cancer (PHASE3)
• Testing Trastuzumab and Pertuzumab in Patients With Higher Than Normal Copies of the HER2 Gene Found in Their Tumors (MATCH - Subprotocol J) (PHASE2)
• Targeted Therapy Directed by Genetic Testing in Treating Patients With Advanced Refractory Solid Tumors, Lymphomas, or Multiple Myeloma (The MATCH Screening Trial) (PHASE2)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Perjeta CI brief — competitive landscape report
• Perjeta updates RSS · CI watch RSS
• Roche portfolio CI