Trastuzumab emtansine (Specialist drug)

Should only be prescribed by a physician and administered under the supervision of a healthcare professional experienced in treating cancer patients, prepared to manage allergic/anaphylactic infusion reactions and where full resuscitation facilities are immediately available. Patients must have HER2-positive tumour status (IHC 3+ or ISH/FISH ratio of 2.0 or more). Check vial labels to ensure the product is trastuzumab emtansine and not another trastuzumab-containing product (e.g. trastuzumab or trastuzumab deruxtecan). Observe patients during the infusion and for at least 90 minutes after the initial infusion (at least 30 minutes after subsequent infusions) for fever, chills or other infusion-related reactions, and monitor the infusion site for subcutaneous infiltration; slow or interrupt the infusion for infusion-related symptoms and discontinue for life-threatening infusion reactions. Duration: early breast cancer — a total of 14 cycles unless there is disease recurrence or unmanageable toxicity; metastatic breast cancer — until disease progression or unmanageable toxicity. Dose reduction schedule from the 3.6 mg/kg starting dose: first reduction 3 mg/kg, second reduction 2.4 mg/kg, and discontinue if further reduction is required; the dose should not be re-escalated after a reduction. Dose modification tables in the SPC cover thrombocytopenia, raised ALT/AST, hyperbilirubinaemia, drug-induced liver injury, nodular regenerative hyperplasia, peripheral neuropathy, left ventricular dysfunction, heart failure and pulmonary toxicity — permanently discontinue for ILD/pneumonitis, nodular regenerative hyperplasia, Grade 4 ALT or AST elevation, total bilirubin more than 2 x ULN, or symptomatic congestive heart failure. Elderly: no dose adjustment in patients aged 65 years or over; insufficient data in patients 75 years and over. Hepatic impairment: no adjustment to the starting dose in mild or moderate impairment; not studied in severe hepatic impairment — treat with caution. Paediatric population: safety and efficacy in children and adolescents below 18 years have not been established as there is no relevant use in the paediatric population for the indication of breast cancer.