Elaprase (idursulfase) — HCPCS J1743
CareCost Estimate · Billing Cheat Sheet
Takeda Pharmaceuticals (formerly Shire)
6 mg / 3 mL single-dose vial
0.5 mg/kg IV weekly (~3 hr)
Reviewed: May 2, 2026
ASP: Q2 2026
Adult dose
~35 units
0.5 mg/kg/wk · 70 kg adult
Modifiers
JZ + JW
JW typical (waste)
Admin CPT
96365 + 96366×2
Therapeutic IV ~3 hr
Medicare ASP+6%
$558.221
/mg · ~$19,538/35 mg
HYPERSENSITIVITY / ANAPHYLAXIS WARNING: ~16% of patients in the Hunter Outcome Survey
experience anaphylactoid/anaphylactic reactions. Most patients develop anti-idursulfase IgG antibodies on
chronic therapy. Severe phenotype patients with respiratory compromise are at highest risk for life-threatening
reactions. Emergency medications, oxygen, IV fluids, airway support, and trained personnel must be
available at every infusion.
Codes & NDC
| HCPCS | J1743 — "Idursulfase injection" (1 mg = 1 unit, permanent code) |
|---|
| NDC | 54092-0700-01 (Takeda labeler 54092) — N4 qualifier, ML units |
|---|
| Vial | 6 mg / 3 mL (2 mg/mL) single-dose vial; refrigerated 2°C–8°C; do not freeze, do not shake |
|---|
| FDA approval | July 24, 2006 (BLA 125151) · orphan drug |
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| Benefit | Medical (provider buy-and-bill); some plans steer to specialty pharmacy |
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Dosing
- 0.5 mg/kg IV once weekly, lifelong (patients ≥5 yr)
- Infusion time ~3 hours with stepwise rate titration
- 70 kg adult: 35 mg/dose — 6 vials drawn, 1 mg discarded
- 18 kg child: 9 mg/dose — 2 vials drawn, 3 mg discarded
- 52 doses/year · round to nearest mg
- Dilute in 100 mL 0.9% NaCl · low-protein-binding 0.2 micron in-line filter
Premedication checklist (every infusion)
- ☐ Antihistamine (e.g., diphenhydramine 1 mg/kg up to 50 mg PO/IV)
- ☐ Antipyretic (e.g., acetaminophen 10–15 mg/kg PO)
- ☐ Given 30–60 min pre-infusion
- ☐ Add corticosteroid if prior reaction history (e.g., methylprednisolone)
- ☐ Epinephrine, oxygen, IV fluids, airway support on-site
- ☐ Trained personnel available throughout infusion + observation
- ☐ Postpone if patient has febrile or respiratory illness
Administration & modifiers
| Code | When |
|---|
96365 | Therapeutic IV, initial up to 1 hr (primary) |
96366 × 2 | Each additional hr — 2 units for 3-hr infusion |
96413 | NOT appropriate — idursulfase is enzyme replacement, not chemo |
| Modifiers: JZ on administered units + JW on discarded units (separate lines, same NDC). JW is typical due to weight-based dosing from fixed 6 mg vials. |
ICD-10 (E76.1 primary)
| Code | For |
|---|
E76.1 | Mucopolysaccharidosis II (Hunter) — primary |
J96.x | Respiratory failure |
I50.x | Heart failure (valve disease, cardiomyopathy) |
G91.x | Hydrocephalus |
H90.x | Hearing loss |
M24.5x | Joint contracture |
K76.89 | Hepatomegaly |
F70–F79 | Intellectual disability (severe phenotype) |
MPS ERT class — one drug per subtype
| Drug | HCPCS | MPS | ICD-10 |
|---|
| Aldurazyme | J1931 | I (Hurler) | E76.0x |
| Elaprase | J1743 | II (Hunter) | E76.1 |
| Vimizim | J1322 | IVA (Morquio A) | E76.219 |
| Naglazyme | J1458 | VI (Maroteaux-Lamy) | E76.29 |
| Mepsevii | J3397 | VII (Sly) | E76.29 |
Not interchangeable. Confirm subtype with enzyme assay + IDS gene results before billing.
Payer requirements (May 2026)
| Payer | PA | Key criteria |
|---|
| UnitedHealthcare | Yes | Confirmed MPS II (enzyme + IDS gene); ≥5 yr; specialist Rx |
| Aetna | Yes | Same diagnostic confirmation; specialist prescriber |
| BCBS plans | Yes | Aligned with FDA label + metabolic specialty guidelines |
| Medicare (MAC) | n/a | Generic biologic LCD; on-label coverage |
No step therapy. Idursulfase is the only FDA-approved ERT for MPS II.
Medicare reimbursement (Q2 2026)
| Field | Value |
|---|
| ASP + 6% | $558.221 / mg (effective 4/1 – 6/30/2026) |
| Single 6 mg vial | $3,349.33 |
| 35 mg dose (~70 kg) | $19,537.74 |
| Annual (52 doses, 70 kg) | ~$1,015,962 |
| Sequestration | ~2% → ~ASP + 4.3% paid |
Site of care
| Setting | POS | Notes |
|---|
| Specialty / metabolic clinic | 11 | Preferred first 6–12 mo |
| Ambulatory infusion suite | 49 | Common for stable patients |
| Hospital outpatient | 22 / 19 | Severe phenotype / high-risk patients |
| Patient home | 12 | Stable, reaction-free, specialty home infusion only |
Patient assistance — Takeda OnePath
- Phone: 1-866-861-1750 (Takeda OnePath / Elaprase Patient Support)
- Benefits investigation, PA assistance, appeals, infusion site coordination
- Commercial copay program for eligible commercially-insured patients (excludes Medicare/Medicaid/TRICARE)
- Patient Assistance Program (PAP): free product for uninsured / underinsured
- Federal patients: NORD MPS II Fund · HealthWell · PAN (verify open quarterly)
- Web: elaprase.com · takedaonepath.com · mpssociety.org
Pending SME review. Staff-authored from FDA label, CMS ASP Q2 2026, Takeda OnePath, and major
payer LCDs. Verify high-stakes claims against linked sources before billing.