EMILIA
In HER2-positive advanced breast cancer previously treated with trastuzumab and a taxane, does T-DM1 improve outcomes versus lapatinib–capecitabine?
Trial design and population
991 patients with HER2-positive locally advanced or metastatic breast cancer previously treated with trastuzumab and a taxane.
T-DM1 3.6 mg/kg IV every 3 weeks vs lapatinib 1,250 mg orally daily plus capecitabine 1,000 mg/m² twice daily days 1–14 every 21 days.
991
PFS and OS
Key results
Median PFS was 9.6 vs 6.4 months (HR 0.65, 95% CI 0.55–0.77); median OS was 30.9 vs 25.1 months (HR 0.68, 95% CI 0.55–0.85). Grade ≥3 AEs occurred in 41% vs 57%.
Source-reported outcome visualization
Median overall survival · Final analysis
Source-reported endpoint and unit. Median survival is not converted into an NNT.
Absolute Effect
Median OS difference 5.8 months is not an NNT. T-DM1 improved PFS and OS while reducing overall grade ≥3 AE frequency versus this comparator.
NNT: Not calculated; median OS difference is not a valid NNT. Do not convert median survival differences into NNT.
NNH: Not quantifiable. T-DM1-associated thrombocytopenia and transaminase elevation were important; lapatinib–capecitabine caused more diarrhoea and hand-foot syndrome. Aggregate grade ≥3 AE rates are not used as NNH without a fixed-time risk framework.
Safety and treatment burden
T-DM1-associated thrombocytopenia and transaminase elevation were important; lapatinib–capecitabine caused more diarrhoea and hand-foot syndrome. Aggregate grade ≥3 AE rates are not used as NNH without a fixed-time risk framework.
Follow-up, maturity and limitations
Final OS analysis; later follow-up extended.
Comparator is historical; T-DM1 has been superseded as preferred second-line treatment in many settings by trastuzumab deruxtecan. HER2 status and prior treatment define applicability.
Clinical interpretation
Current-practice context · reviewed 20 October 2026
Historical evidence is separated from current sequencing. Confirm current guidelines, local regulatory status, biomarkers, prior therapies and patient-specific contraindications. Newer treatments may have changed the preferred sequence; where NNT/NNH cannot be defensibly quantified, no surrogate calculation is made.