Targeted Therapy / Oncology — Breast Cancer

Perjeta (pertuzumab)

Genentech / Roche · HER2 Dimerization Inhibitor

FDA Approved 2012 Intravenous (IV) infusion Specialty Medication
Perjeta pertuzumab vials, Genentech Roche

What is Perjeta? Perjeta (pertuzumab) is a HER2 dimerization inhibitor by Genentech/Roche used with trastuzumab and chemotherapy for HER2-positive breast cancer. Combined pertuzumab + trastuzumab + docetaxel (PHD) is a standard first-line regimen for metastatic HER2+ breast cancer.

About Perjeta

Brand NamePerjeta
Generic / INNpertuzumab
Drug ClassHER2 Dimerization Inhibitor
ManufacturerGenentech / Roche
AdministrationIntravenous (IV) infusion
FDA Approval2012
📦 420 mg/14 mL vials. Also available in Phesgo (pertuzumab + trastuzumab + hyaluronidase SC).

FDA-Approved Uses

  • HER2-positive metastatic breast cancer — with trastuzumab and docetaxel as first-line
  • HER2-positive early breast cancer — neoadjuvant (with trastuzumab and chemotherapy)
  • HER2-positive early breast cancer — adjuvant (with trastuzumab after neoadjuvant)
Biomarker Note: HER2 overexpression (IHC 3+ or ISH-amplified) required. Not for HER2-negative tumors.

How Does Perjeta Work?

Pertuzumab binds HER2 at a different epitope from trastuzumab, blocking HER2 dimerization with HER3 and other HER family members. Combined with trastuzumab, this provides dual HER2 blockade producing synergistic anti-tumor activity.

Dosage & Administration

840 mg IV loading dose, then 420 mg every 3 weeks. First infusion over 60 minutes; if tolerated, subsequent over 30 minutes. Always combined with trastuzumab.

⚠️ Important

Dosing is individualized by the treating oncologist. Do not adjust without medical guidance. This page is educational only.

Warnings & Side Effects

Cardiomyopathy — evaluate LVEF before and during treatment. Embryo-fetal toxicity. Infusion-related reactions. Diarrhea.

⛔ Serious Warnings
  • Cardiomyopathy / decreased LVEF
  • Embryo-fetal toxicity
  • Infusion-related reactions

Common Side Effects

  • Diarrhea
  • Alopecia
  • Nausea
  • Fatigue
  • Rash
  • Peripheral neuropathy
  • Infusion-related reactions

Storage & Handling

Refrigerate at 2°C to 8°C (36°F to 46°F). Do not freeze.

💰 Medication Cost & Insurance Coverage

Approximate Wholesale Acquisition Cost (WAC / List Price)

~$4,000–$7,000/cycle

420mg every 3 weeks

Coverage note: Medicare Part B; often with trastuzumab
⚠️ List Price vs. What You Pay

WAC is the manufacturer list price — not what most patients pay. Actual cost depends on insurance, deductible, copay tier, and patient assistance eligibility. Many patients pay $0–$100/month through manufacturer co-pay programs.

Patient Assistance Prior Authorization Insurance & Savings

Insurance & Prior Authorization

Perjeta requires prior authorization from all major insurance plans. BiologicHealthPlus handles the full PA process — clinical documentation, peer-to-peer reviews, and appeals — at no cost to patients or providers.

Prior Authorization Guide Patient Assistance Insurance & Savings

Frequently Asked Questions — Perjeta

Perjeta is a HER2 dimerization inhibitor that blocks HER2 from pairing with HER3. Combined with trastuzumab and chemotherapy it is standard first-line therapy for metastatic HER2+ breast cancer.

Yes — Phesgo combines pertuzumab + trastuzumab + hyaluronidase as a fixed SC injection given in approximately 5–8 minutes.

Perjeta is covered by Medicare Part B and commercial insurance for HER2+ breast cancer with prior authorization.

Related Medications

Herceptin (trastuzumab)  ·  Kadcyla (T-DM1)  ·  Enhertu  ·  Phesgo (SC combination)

Related Conditions

HER2-positive breast cancer  ·  Metastatic HER2+ breast cancer  ·  Early breast cancer

Medical Disclaimer: Educational purposes only. Not medical advice. Consult your oncologist for treatment decisions. Prices are approximate WAC list prices as of 2025-2026. Last reviewed: September 2026 — BiologicHealthPlus Clinical Team.