Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Anti-HER2 antibody-drug conjugate

Trastuzumab emtansine (Specialist drug)

Brand names: Kadcyla

Trastuzumab emtansine is an antibody-drug conjugate used under specialist supervision for HER2-positive breast cancer, particularly after prior trastuzumab-based therapy.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

A HER2-targeting antibody delivers the microtubule inhibitor DM1 (emtansine) into HER2-positive cells, disrupting the cytoskeleton and causing cell death while retaining HER2-blocking activity.

Prescribing in practice

  • Hepatotoxicity and thrombocytopenia are key risks — check liver function and platelets before each dose and withhold for significant abnormalities.
  • It must not be substituted for trastuzumab and is given only by oncology specialists for confirmed HER2-positive disease.
  • Cardiac function should be assessed as with other HER2-directed therapies.

Monitoring

Monitor platelet count, liver function and left ventricular ejection fraction before each dose and during treatment.

Counselling the patient

  • Report unusual bruising or bleeding, yellowing of the skin or eyes, or breathlessness.
  • Mention any infusion reaction during or after treatment.
  • Use effective contraception during and after therapy.

Evidence & guidelines

Benefit in pretreated HER2-positive breast cancer is established by the EMILIA and KATHERINE trials and supported by NICE guidance.

Reference: NICE TA458/TA632; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Drugs
Pathways