Ziihera (zanidatamab-hrii) — HCPCS J9276

CareCost Estimate · Billing Cheat Sheet
Jazz Pharmaceuticals 300 mg lyophilized vial (50 mg/mL after recon) IV infusion 60 min first / 30 min subsequent Reviewed: May 21, 2026 ASP: Q2 2026
HCPCS
J9276
1 unit = 2 mg
Std dose (70 kg)
700 units
20 mg/kg q14d (weight-based)
Modifier
JW + JZ
Both lines (vial waste typical)
Admin CPT
96413
single substance, 60 min first / 30 min subsequent
Medicare ASP+6%
$24.996
/unit (2 mg) · $17,497/70 kg dose

Codes & NDC

HCPCSJ9276 — "Injection, zanidatamab-hrii, 2 mg" (permanent, eff 7/1/2025)
Prior C-codeC9302 — transitional pass-through (OPPS only); eff 4/1/2025, deactivated 6/30/2025
Genericzanidatamab-hrii (HER2-targeted bispecific antibody)
NDC68727-950-01 single-dose carton (verify 11-digit on current DailyMed); N4 qualifier in 24A shaded
Vial300 mg lyophilized powder; reconstitute with 6 mL SWFI → 50 mg/mL (~6 mL withdrawable); 5 vials per typical 70 kg dose
Diluent0.9% NaCl ONLY (NOT 5% Dextrose); 250 mL bag; gentle inversion; do not shake; 0.2/0.22 µm in-line filter
BenefitMedical (provider buy-and-bill); not specialty pharmacy
Pre-4/1/25J3490 / J9999 unclassified + NDC documentation

Indications & dosing matrix

IndicationDoseScheduleSetting
HER2+ (IHC 3+) intrahepatic cholangiocarcinoma (C22.1)20 mg/kgq14dMono
HER2+ (IHC 3+) gallbladder carcinoma (C23)20 mg/kgq14dMono
HER2+ (IHC 3+) extrahepatic cholangiocarcinoma (C24.x)20 mg/kgq14dMono
Weight-based — 20 mg/kg q14d. All BTC subtypes share same dose. First infusion 60 min; subsequent 30 min if tolerated. Previously treated unresectable/metastatic only.

Unit math (worked example, 70 kg)

  • 70 kg × 20 mg/kg = 1400 mg
  • Vials drawn: ceil(1400/300) = 5 × 300 = 1500 mg drawn
  • Admin: 1400 mg = 700 units (JZ) [÷ 2 because 1 unit = 2 mg]
  • Waste: 100 mg = 50 units (JW)
  • NDC qty on claim = mL drawn (~28 mL of reconstituted 50 mg/mL)
UNIT MATH WARNING: J9276 is 2 mg = 1 unit (NOT 1 mg = 1 unit like Bizengri). 1400 mg = 700 units, NOT 1400. Doubling units triggers payment-limit denials.

Ziihera vs Bizengri — DO NOT CONFUSE

Ziihera J9276Bizengri J9382
Genericzanidatamab-hriizenocutuzumab-zbco
ManufacturerJazz PharmaceuticalsMerus N.V.
TargetHER2 bispecificHER2/HER3 bispecific
BiomarkerHER2 IHC 3+NRG1 fusion+
IndicationHER2+ biliary tract cancer (BTC)NRG1+ NSCLC / pancreatic
FDA approvalNov 20, 2024Dec 4, 2024
Dose20 mg/kg q14d (weight)750 mg q14d (flat)
Unit2 mg = 1 unit1 mg = 1 unit
Two different drugs — not the same. Wrong HCPCS = denial. Verify product dispensed matches J-code AND unit math.

Administration & modifiers

CodeWhen
96413 × 1Chemo IV, single substance, first 60 min (every Ziihera dose — first and subsequent)
96415Only if infusion extends past 60 min (rare — reactions only)
96365NOT appropriate — Ziihera is an antineoplastic mAb (chemo admin codes)
JZ + JW both lines. 300 mg vial vs weight-based 20 mg/kg dose = vial waste on most patients. Standard 70 kg = 700 JZ + 50 JW. Zero waste only at exact-multiple weights (e.g., 90 kg = 900 JZ, no JW).

ICD-10 by indication

CodeFor
C22.1Intrahepatic bile duct carcinoma (intrahepatic cholangiocarcinoma)
C23Malignant neoplasm of gallbladder
C24.0Extrahepatic bile duct (perihilar/distal CBD)
C24.1Ampulla of Vater
C24.8 / C24.9Overlapping / biliary tract unspecified
C78.0xSecondary lung mets (common BTC met)
C78.6Secondary peritoneum/retroperitoneum (common BTC met)
C78.7Secondary liver mets (for extrahepatic primary)
C79.51 / C77.xBone mets / lymph node mets (paired)

Payer requirements (May 2026)

PayerPAHER2 IHC 3+ focus
UnitedHealthcareYesFDA-approved companion diagnostic; previously treated (gem+cis ± durva); baseline LVEF
Aetna (CPB 1075)YesVENTANA PATHWAY 4B5 or equivalent; NCCN-aligned; ECOG documentation
BCBS plansYesNCCN-aligned; HER2 IHC 3+ report; some plans require baseline LVEF
Carelon (Anthem)YesZiihera-specific policy; HER2 IHC 3+ confirmed; appropriate prior systemic therapy
MedicareNoMAC LCDs; HER2 IHC 3+ documentation + appropriate ICD-10 (C22.1/C23/C24.x)
#1 DENIAL: HER2 IHC 3+ documentation missing or IHC 2+ submitted. IHC 2+ NOT eligible (even with ISH amplification). Submit full pathology report: antibody clone (4B5), intensity, % positive cells, CAP/CLIA lab.

Medicare reimbursement (Q2 2026)

FieldValue
ASP + 6%$24.996 / unit (2 mg) ≈ $12.498/mg (eff. 4/1 – 6/30/2026)
70 kg dose (1400 mg / 700 units)$17,497.20 admin + ~$1,250 JW (50 units) = ~$18,747 total
90 kg dose (1800 mg / 900 units)$22,496.40 (exact 6-vial; zero waste)
Annualized (70 kg, 26 doses)~$487,400/yr admin (+JW ~$32K) pre-sequestration
After ~2% sequestration~$509,500/yr actual paid (70 kg)

Site of care (J9276 = all sites)

SettingPOSNotes
Physician oncology office11Preferred Cycle 2+ (30-min infusion)
Ambulatory infusion suite49Preferred
Oncology ASC24Acceptable
Hospital outpatient19/22OK Cycle 1 (60-min first dose); disfavored Cycle 2+ by UM
J9276 (perm code) bills universally. During C9302 transitional (4/1–6/30/2025), HOPD-only billing. Audit straddle claims by DOS.

Patient assistance — JazzCares

  • Phone: 1-833-533-JAZZ (1-833-533-5299)
  • Web: jazzcares.com
  • Ziihera Copay Program: commercial pts reduced OOP per infusion (excl Medicare/Medicaid/federal)
  • Jazz PAP: free product for uninsured/underinsured meeting income criteria
  • HER2 IHC testing assistance: JazzCares can coordinate HER2 IHC 3+ testing for not-yet-tested BTC patients
  • Foundations (Medicare): PAN, HealthWell, CancerCare, Good Days, Cholangiocarcinoma Foundation — verify open funds quarterly
TOP 3 DENIAL DRIVERS: (1) HER2 IHC 3+ documentation missing — submit pathology report with antibody clone (4B5), intensity, % positive cells, CAP/CLIA lab; IHC 2+ NOT eligible regardless of ISH; (2) Cross-product confusion with Bizengri (zenocutuzumab, J9382, NRG1+ NSCLC/pancreatic) — verify product matches J-code AND unit (Ziihera = 2 mg/unit, Bizengri = 1 mg/unit); (3) Missing JW line on weight-based dose with vial waste (most claims need both JZ + JW).
FIRST-IN-CLASS HER2-directed therapy for biliary tract cancer. No competitor product. NCCN compendium support Category 2A. Accelerated approval Nov 20, 2024 — continued approval contingent on confirmatory trial (HERIZON-BTC-302).
Sources: FDA label (BLA 761416, Nov 2024), DailyMed, JazzCares Billing & Coding Guide, CMS ASP Q2 2026, CMS HCPCS Quarterly Update (J9276 eff 7/1/25, C9302 deact 6/30/25), NCCN Biliary Tract Cancers, UHC Oncology Med Coverage Policy, Aetna CPB 1075, Carelon Clinical Criteria, HERIZON-BTC-01 (NCT04466891). carecostestimate.com/drugs/ziihera