Latest Cancer TreatmentsDr. Mohammadreza Dabiri
Dr. Mohammadreza Dabiriفارسی
Treatment regimen

Trastuzumab emtansine (T-DM1, Kadcyla): dose and schedule

3.6 mg/kg every 3 weeks; HER2-positive residual disease and metastatic disease

Updated: 28 October 20261 min read2 references

Summary for doctors

  • Residual invasive disease after neoadjuvant anti-HER2 treatment: 14 cycles [1].
  • It roughly halved invasive recurrence (3-year invasive disease-free survival 88.3% vs 77.0%) [1].
  • Do not substitute with trastuzumab or T-DXd; the doses are different.

Dose and schedule

T-DM1

HER2-positive breast cancer: residual disease (adjuvant) or metastatic diseaseCycle length: Every 21 days

HER2-positive breast cancer: residual disease (adjuvant) or metastatic disease

DrugDoseRouteSchedule
Trastuzumab emtansine3.6 mg/kgIV (first dose over 90 minutes, then 30 minutes)Day 1
Cycle length
Every 21 days
Duration
Adjuvant: 14 cycles [1]; metastatic: until progression

Dose reduction: 3 mg/kg, then 2.4; below that, stop [1].

Dose source: [2].

Evidence: KATHERINE (2019)

Doses follow the trial protocol, guideline or official drug label (source given in the notes of each regimen). Before prescribing, check blood counts, renal and hepatic function, drug interactions and the patient’s condition, and adjust the dose according to the drug label.

Premedication and supportive care

  • Antiemetics: low emetogenicity.
  • Routine premedication is not needed; monitor for infusion reactions with the first dose.

Monitoring and dose adjustment

  • Platelet count and liver enzymes before each dose; thrombocytopenia and raised enzymes are the most common reasons for dose reduction [1].
  • Left ventricular ejection fraction (echo or MUGA) before starting and every 3 months during anti-HER2 treatment.
  • Peripheral neuropathy and a new cough or dyspnoea (pneumonitis).

Main evidence

Show detailsHide

KATHERINE: in 1486 patients with residual disease, T-DM1 vs trastuzumab increased 3-year invasive disease-free survival from 77.0% to 88.3% [1].

Related cancer types

Breast cancer

Treatment regimens (physicians)

AC followed by paclitaxel (dose-dense and weekly)TC regimen (docetaxel and cyclophosphamide): dose and scheduleTCHP regimen: dose and schedule in HER2-positive breast cancerWeekly paclitaxel with trastuzumab (APT regimen)KEYNOTE-522 regimen: pembrolizumab and chemotherapy in triple-negative breast cancerTrastuzumab deruxtecan (T-DXd, Enhertu): dose and monitoringAdjuvant capecitabine after neoadjuvant treatment (CREATE-X)Sacituzumab govitecan (Trodelvy)Pembrolizumab with chemotherapy in metastatic triple-negative breast cancer (KEYNOTE-355)

Physician tools and lessons

Cumulative Anthracycline Dose and Doxorubicin Equivalents10 cheap steps that save patients' livesBone-modifying agents in cancer: bone metastases, adjuvant use and osteonecrosis of the jawGermline genetic testing in cancer: who, and which genes?Management of brain metastasesFertility preservation before cancer treatmentMalignant pleural effusion: drainage, pleurodesis or an indwelling catheterCancer during pregnancy: chemotherapy and decisions

References

2 references
Show all references, 1 with a study cardClose the reference list

Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.

  1. 1
    Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancervon Minckwitz G, Huang CS, Mano MS, et al · N Engl J Med · 2019;380:617-628
    Study cardDOIPubMed Back to text: 1 2 3 4 5 6
  2. 2
    KADCYLA (ADO-TRASTUZUMAB EMTANSINE) — Prescribing InformationGenentech, Inc · FDA label · 2026
    Source Back to text

This page is based on reputable scientific sources and was last updated on 28 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.

Printed from the website; the full and up-to-date version: https://drdabiri.com/en/regimens/trastuzumab-emtansine-tdm1/

Related pages

27 October 2026 FOLFOX (mFOLFOX6): dose, schedule and side effects Dose and schedule of mFOLFOX6 (oxaliplatin 85, leucovorin 400, fluorouracil 400 bolus and 2400 as a 46-hour infusion), length of adjuvant treatment, premedication, neuropathy and dose adjustment. 27 October 2026 CAPOX (XELOX): dose, schedule and side effects Dose and schedule of CAPOX or XELOX (oxaliplatin 130 and capecitabine 1000 twice daily, days 1 to 14), length of adjuvant treatment, renal adjustment and side effects. 27 October 2026 FOLFIRI regimen: dose, schedule and side effects Dose and schedule of FOLFIRI (irinotecan 180, leucovorin 400, fluorouracil 400 bolus and 2400 as a 46-hour infusion), diarrhoea control, UGT1A1 and dose adjustment.