Trastuzumab

Medicare

Part B (clinician-administered)

Given by infusion or injection in a clinic or hospital outpatient department, so it is a Part B drug: Medicare pays 80% after the Part B deductible and the patient owes 20% coinsurance, uncapped in Original Medicare unless a Medigap policy applies. HCPCS J9355 for Herceptin; each biosimilar has its own Q-code. Under the Inflation Reduction Act, Part B coinsurance on a biosimilar is calculated on the reference product's price, so biosimilars usually cost the patient less.

Commercial insurance

step therapy common

Most commercial plans and PBM medical-benefit programmes now require a preferred trastuzumab biosimilar (e.g. Kanjinti, Ogivri, Trazimera) before the originator; prior authorisation confirms HER2 status.

Assistance programmes

• Genentech Access Solutions
• Genentech Patient Foundation — Free medicine for eligible patients regardless of insurance type.
• PAN Foundation — Disease-specific co-pay and premium funds; open and closed funds change monthly.
• HealthWell Foundation
• CancerCare Co-Payment Assistance Foundation
• Patient Advocate Foundation Co-Pay Relief

20% Part B coinsurance on a high-cost infusion adds up quickly: Medigap Plan G or N, Medicare Advantage maximum out-of-pocket, Medicaid dual eligibility, or a charity fund are the usual buffers.

Sources: Medicare.gov: Chemotherapy · Medicare.gov: Prescription drugs (outpatient, Part B) · FDA: Biosimilars. Not medical or financial advice; verify with your plan.

Appraised for

HER2-positive advanced breast cancer

Notes

Adjuvant early breast cancer: TA107 (2006). HER2-positive gastric cancer: TA208 (2010). Biosimilars and the subcutaneous form are used under the same guidance and have cut the NHS price substantially.

NHS England

Routinely funded for the appraised indication (or via managed access)

Sources: NICE TA34 · SMC advice: trastuzumab. Funding decisions are indication-specific and change monthly; verify with NICE and your treating team.