Trastuzumab emtansine (T-DM1) is an antibody–drug conjugate, comprised of a highly potent cytotoxic agent, DM1, connected via a stable linker to the anti-HER2 antibody, trastuzumab, thereby primarily targeting chemotherapy delivery to cells overexpressing the HER2 receptor while minimizing the systemic exposure.
Mechanism of Action:
Upon binding to sub-domain IV of the HER2 receptor, PADYNEX undergoes receptor-mediated internalization and subsequent lysosomal degradation, resulting in intracellular release of DM1-containing cytotoxic catabolites. Binding of DM1 to tubulin disrupts microtubule networks in the cell, which results in cell cycle arrest and apoptotic cell death.
PADYNEX indicated, as a single agent, for:
• Treatment of patients with HER2-positive, metastatic breast cancer who previously received trastuzumab and a taxane, separately or in combination. Patients should have either:
• received prior therapy for metastatic disease,
• developed disease recurrence during or within six months of completing adjuvant therapy
• Adjuvant treatment of patients with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment.
Dosage form and strengths:
Lyophilized powder in single-dose vials: 100 mg, 160 mg
After reconstitution and dilution, PADYNEX should be administered as an intravenous infusion only with a 0.2 or 0.22 micron in-line polyethersulfone (PES) filter in 30 to 90 minutes.