Antibody-drug conjugate (HER2)
Enhertu (fam-trastuzumab deruxtecan-nxki) cost
Manufacturer: Daiichi Sankyo / AstraZeneca · Route: injection/infusion (Part B) · HCPCS: J9358 · Last updated
Medicare spending — 2023
$65,411
Average total Medicare spending per beneficiary per year
$9,850
Average spending per claim
$26.02
Average Sales Price per mg
Source: CMS Medicare Part B Spending by Drug, data year 2023.
What patients actually pay
The $65,411 figure above is total Medicare spending — the government's payment — not what a patient pays out of pocket. Actual out-of-pocket varies widely:
- Original Medicare + Medigap supplemental policy: typically covers most of the 20% Part B coinsurance, leaving minimal out-of-pocket.
- Medicare Advantage: caps annual out-of-pocket spending ($8,850 in 2024 for in-network care, lower for some plans).
- Commercial insurance: copay or coinsurance varies; specialty drugs often require prior authorization. See "financial assistance" below.
- Uninsured: manufacturer patient assistance programs can provide Enhertu at no cost for income-eligible patients. See below.
The ASP of $26.02 per milligram is the federal Medicare reimbursement rate. Dose depends on your weight and indication — most Enhertu regimens are hundreds to thousands of mg per cycle.
Cancers this drug treats
FDA-approved indications for Enhertu on our site. For each, see the complete treatment landscape plus active clinical trials.
Financial assistance for Enhertu
The manufacturer of Enhertu offers a patient assistance program. Disease-specific foundations also fund copay assistance for the cancers this drug treats.
AstraZeneca Access 360
Manufacturer programbenefits investigation · prior authorization support · affordability programs (commercial + uninsured)
https://www.myaccess360.com/ · 844-275-2360
Disease foundations with funds covering Enhertu's cancers
HealthWell Foundation
copay, premium, and deductible assistance for insured patients; fund availability varies by disease
https://www.healthwellfoundation.org/disease-funds/
Funds open and close based on availability; check disease-funds page for current status
Patient Access Network (PAN) Foundation
copay assistance for 20+ cancer types via disease-specific funds
https://www.panfoundation.org/find-disease-fund/ · 866-316-7263
Merging with Patient Advocate Foundation; unified 'TotalAssist' program launches 2026-07-01
Patient Advocate Foundation Co-Pay Relief
direct copay / coinsurance assistance via disease-specific funds
https://copays.org/ · 866-512-3861
Merging with PAN Foundation; launching 'TotalAssist' 2026-07-01
CancerCare Co-Payment Assistance Foundation
copay assistance for chemotherapy and targeted treatment medications
https://www.cancercare.org/copayfoundation · 866-552-6729
CancerCare Financial Assistance
limited financial assistance for transportation, home care, child care, and treatment-related costs
https://www.cancercare.org/financial · 800-813-4673
Susan G. Komen Financial Assistance
patient navigation + financial assistance for breast cancer patients
https://www.komen.org/support-resources/financial-assistance/
Also try these directory aggregators: NeedyMeds, RxAssist, Cancer Financial Assistance Coalition (CFAC).
Clinical trials using Enhertu
Trials testing fam-trastuzumab deruxtecan-nxki in new combinations, new cancer types, or earlier lines of therapy. Trials often cover the cost of the drug.
Or search ClinicalTrials.gov directly for fam-trastuzumab deruxtecan-nxki.