Improper assay performance, including use of sub-optimally fixed tissue, failure to utilize specified reagents, deviation from specific assay instructions, and failure to include appropriate controls for assay validation, can lead to unreliable results.
Recommended Doses and Schedules: Do not substitute trastuzumab for or with KADCYLA.
The recommended dose of KADCYLA is 3.6 mg/kg given as an intravenous infusion every 3 weeks (21-day cycle). Do not administer KADCYLA at doses greater than 3.6 mg/kg.
Closely monitor the infusion site for possible subcutaneous infiltration during drug administration [see Extravasation under Precautions].
First infusion: Administer infusion over 90 minutes. Observe patients during the infusion and for at least 90 minutes following the initial dose for fever, chills, or other infusion-related reactions [see Infusion-Related Reactions, Hypersensitivity Reactions under Precautions].
Subsequent infusions: Administer over 30 minutes if prior infusions were well tolerated. Observe patients during the infusion and for at least 30 minutes after infusion.
Metastatic Breast Cancer (MBC): Patients with MBC should receive treatment until disease progression or unmanageable toxicity.
Early Breast Cancer (EBC): Patients with EBC should receive treatment for a total of 14 cycles unless there is disease recurrence or unmanageable toxicity.
Dose Modifications: Do not re-escalate the KADCYLA dose after a dose reduction is made.
If a planned dose is delayed or missed, administer as soon as possible; do not wait until the next planned cycle. Adjust the schedule of administration to maintain a 3-week interval between doses. Administer the infusion at the dose and rate the patient tolerated in the most recent infusion.
Slow or interrupt the infusion rate of KADCYLA if the patient develops an infusion-related reaction. Permanently discontinue KADCYLA for life-threatening infusion-related reactions [see Infusion-Related Reactions, Hypersensitivity Reactions under Precautions].
Management of increased serum transaminases, hyperbilirubinemia, left ventricular dysfunction, thrombocytopenia, pulmonary toxicity or peripheral neuropathy may require temporary interruption, dose reduction or treatment discontinuation of KADCYLA as per guidelines provided in Tables 3 and 4. (See Tables 3 and 4.)

