(Key considerations when prescribing and monitoring)
Check LFTs before every cycle – risk of hepatotoxicity and NRH.
Assess LVEF regularly – HER2-targeted cardiotoxicity; avoid in uncontrolled cardiac disease.
Check platelet count before each dose – thrombocytopenia is common; hold if low.
Monitor for cough/dyspnoea – rule out ILD/pneumonitis; stop if confirmed.
Watch for neuropathy – DM1 component can worsen peripheral neuropathy.
Increased bleeding risk – caution with anticoagulants; mucosal bleeding possible.
Infusion/hypersensitivity reactions – monitor closely during infusion.
Not interchangeable with trastuzumab – different drug, dose, and formulation.
Generic name: Trastuzumab emtansine (T-DM1)
Brand name: Kadcyla®
Drug class: HER2-targeted antibody–drug conjugate (trastuzumab + DM1 microtubule inhibitor)
Formulation: Powder for concentrate for IV infusion (100 mg, 160 mg vials)
Mechanism: Binds HER2 → internalised → releases DM1 to inhibit microtubules; maintains trastuzumab-mediated HER2 blockade.
HER2-positive breast cancer:
Metastatic breast cancer (MBC): After prior trastuzumab and taxane.
Early breast cancer (adjuvant): As per regional approval (e.g., residual disease after neoadjuvant therapy).
Follow local regulatory approvals and oncology guidelines.
Dose: 3.6 mg/kg IV every 3 weeks.
First infusion: 90 minutes → observe ≥ 90 minutes post-infusion.
Subsequent infusions: 30 minutes → observe ≥ 30 minutes.
Route: IV only; do not give as IV push/bolus.
Preparation: Reconstitute to 20 mg/mL; dilute per aseptic technique; do NOT mix with other IV drugs.
Treatment duration: Until progression or unacceptable toxicity.
Missed dose: Administer as soon as possible; do not double dose.
Hepatotoxicity:
Hold or discontinue depending on severity.
Permanently discontinue for severe liver injury or confirmed NRH.
Thrombocytopenia:
Hold treatment if platelets are low; resume or reduce dose once recovered.
Infusion reactions:
Mild/moderate → slow or interrupt infusion.
Severe/anaphylaxis → discontinue permanently.
Pulmonary toxicity:
Hold for suspected ILD; discontinue if confirmed.
Cardiac dysfunction:
Hold for significant LVEF drop; discontinue for persistent or symptomatic heart failure.
Avoid concurrent anthracyclines – additive cardiotoxicity.
Caution with anticoagulants – due to thrombocytopenia-related bleeding risk.
Check all medications for potential hepatic interactions – elevated LFT risk.
Certain macrolides, azoles, HIV protease inhibitors, and nefazodone may increase toxicity risk; clinical judgement required.
(Trastuzumab emtansine is not heavily CYP-dependent but interaction risk is clinically relevant due to toxicity profile.)
Hypersensitivity to trastuzumab emtansine or components.
Pregnancy (embryo-foetal toxicity).
Breastfeeding (stop during and for 7 months after treatment).
Not recommended in children (<18 years).
Baseline:
FBC (with platelets)
LFTs (ALT/AST/bilirubin)
Renal function
LVEF (echo or MUGA)
Neuropathy assessment
Each cycle:
Platelets
LFTs
Clinical review (cough, dyspnoea, neuropathy, bleeding signs, cardiac symptoms)
Ongoing:
LVEF every 3 months or sooner if symptomatic.
Monitor during and after infusions.
Common / Very Common:
Thrombocytopenia
Elevated LFTs
Fatigue
Nausea, vomiting, diarrhoea, constipation
Peripheral neuropathy
Epistaxis, mucosal bleeding
Infusion reactions
Serious:
Hepatic failure / NRH
Heart failure, LVEF decline
Interstitial lung disease / pneumonitis
Severe bleeding
Severe hypersensitivity reactions
Pregnancy: Contraindicated – use contraception during and for 7 months after therapy.
Elderly: No dose adjustment required; monitor organ function.
Renal impairment: Use caution; limited data in severe impairment/dialysis.
Hepatic impairment: Avoid in severe hepatic impairment; increased toxicity risk.
Diabetes: Contains sucrose; may affect glycaemic control.
Stop treatment if:
Disease progression
Severe hepatotoxicity or NRH
Confirmed ILD/pneumonitis
Persistent LVEF decline or symptomatic heart failure
Severe thrombocytopenia/bleeding
Severe infusion/hypersensitivity reaction
Continue otherwise until progression or toxicity.
| Trade Name | Trastuzumab Emtansine |
|---|---|
| Drug Class | Antibody-drug Conjugate |
| Cost | |
| Company | |
|---|---|
| Drug Rep | Admin |
| Indications | Breast Cancer |
| Dosage |