Bizengri (zenocutuzumab-zbco)
Merus N.V. / PTX Therapeutics · Bispecific Antibody — HER2 × HER3 Targeted Therapy
What is Bizengri? Bizengri (zenocutuzumab-zbco) is a bispecific antibody targeting HER2 and HER3. It is FDA-approved for adult patients with unresectable or metastatic NRG1 gene fusion-positive non-small cell lung cancer (NSCLC) or pancreatic adenocarcinoma following prior systemic therapy.
About Bizengri
| Brand Name | Bizengri |
| Generic / INN | zenocutuzumab-zbco |
| Drug Class | Bispecific Antibody — HER2 × HER3 Targeted Therapy |
| Manufacturer | Merus N.V. / PTX Therapeutics |
| Administration | Intravenous (IV) infusion |
| FDA Approval | 2023 |
FDA-Approved Uses for Bizengri
Indications are based on FDA approval. Your healthcare provider determines appropriate use based on your specific diagnosis, stage, biomarker status, and overall clinical picture.
- Unresectable or metastatic NRG1 gene fusion-positive non-small cell lung cancer (NSCLC) — after prior systemic therapy
- Unresectable or metastatic NRG1 gene fusion-positive pancreatic adenocarcinoma — after prior systemic therapy
How Does Bizengri Work?
Zenocutuzumab is a bispecific antibody that simultaneously binds HER2 and HER3. NRG1 fusions produce aberrant neuregulin-1 (NRG1) protein that activates HER3 signaling. Bizengri blocks NRG1 from binding to HER3, preventing HER2:HER3 heterodimerization and downstream PI3K/AKT and MAPK signaling that drives tumor growth in NRG1 fusion-positive cancers.
Dosage & Administration
750 mg IV infusion every 2 weeks (Q2W) until disease progression or unacceptable toxicity. The prescribing oncologist determines dose modifications based on toxicity.
Dosing is individualized by the prescribing clinician. Never adjust your dose without consulting your healthcare provider. This information is educational only and does not replace the official prescribing information.
Warnings, Precautions & Side Effects
General Warning
Infusion-related reactions. Interstitial lung disease / pneumonitis. Embryo-fetal toxicity. Monitor left ventricular ejection fraction (LVEF).
- Infusion-related reactions
- Interstitial lung disease / pneumonitis
- Decreased LVEF
- Embryo-fetal toxicity
Common Side Effects
- Fatigue
- Nausea
- Diarrhea
- Infusion-related reaction
- Constipation
- Decreased appetite
- Peripheral edema
This is not a complete list. Always report new or worsening symptoms to your healthcare provider promptly.
Storage & Handling
Refrigerate at 2°C to 8°C (36°F to 46°F). Do not freeze. Protect from light.
BiologicHealthPlus provides temperature-monitored cold-chain specialty delivery for medications requiring refrigeration. Never use a medication if its storage conditions have been compromised.
Insurance Coverage, Prior Authorization & Patient Assistance
🛡️ Commercial Insurance
Bizengri is covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage tier and cost-sharing vary by plan.
✅ Prior Authorization
Prior authorization is required by virtually all insurance plans for Bizengri. BiologicHealthPlus handles the complete prior authorization process at no cost to patients or providers.
🏥 Medicare Coverage
Medicare Part B covers this IV medication when administered in a clinical setting. Medicaid coverage varies by state.
🆓 Patient Assistance
Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. Contact BiologicHealthPlus for a confidential eligibility review.
Prior Authorization Patient Assistance Insurance & Savings Medication Costs
Frequently Asked Questions — Bizengri
Bizengri (zenocutuzumab-zbco) is a bispecific antibody targeting HER2 and HER3, approved for NRG1 gene fusion-positive non-small cell lung cancer and pancreatic adenocarcinoma after prior systemic therapy.
NRG1 (neuregulin-1) gene fusions are rare genomic alterations in which the NRG1 gene is fused to another gene, producing an abnormal protein that overstimulates HER3 signaling and drives tumor growth. NRG1 fusions occur in roughly 0.5–3% of NSCLCs.
Bizengri simultaneously binds HER2 and HER3, blocking the neuregulin-1 protein (produced by NRG1 fusions) from activating HER3. This prevents HER2:HER3 dimerization and shuts down downstream tumor growth signaling.
As a newer targeted oncology agent, Bizengri requires prior authorization from essentially all insurance plans. Coverage depends on NRG1 fusion documentation and the indication. BiologicHealthPlus can complete benefits verification and manage the PA process.
Yes. NRG1 gene fusion testing is required to determine eligibility. This is typically done via next-generation sequencing (NGS) of tumor tissue or liquid biopsy.
Related Medications & Conditions
Related Medications
Keytruda (pembrolizumab) · Trastuzumab (Herceptin) · Pertuzumab (Perjeta) · Gemcitabine
Related Conditions
NRG1 fusion-positive NSCLC · NRG1 fusion-positive pancreatic cancer · HER2/HER3 signaling tumors