palbociclib + trastuzumab emtansine

Palbociclib + trastuzumab emtansine is a combination therapy evaluated for the treatment of HER2-positive breast cancer, particularly in patients with disease that has relapsed after prior therapies. Palbociclib (PD-0332991) is an oral small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), which blocks cell cycle progression in tumor cells with intact retinoblastoma protein. Trastuzumab emtansine (T-DM1, Kadcyla) is an antibody-drug conjugate composed of the monoclonal antibody trastuzumab linked to the cytotoxic agent DM1; it targets HER2-positive tumor cells, delivering DM1 directly to these cells and inhibiting microtubule assembly. The combination leverages complementary mechanisms: CDK4/6 inhibition suppresses proliferation and may resensitize tumors resistant to HER2-targeted therapy, while T-DM1 provides targeted cytotoxicity. This regimen has shown safety and preliminary efficacy in phase I/Ib trials for previously treated HER2-positive metastatic breast cancer[1][3][5][6].

Brand names

Kadcyla

Other names

ado-trastuzumab emtansine