tucatinib + trastuzumab + fluorouracil + leucovorin + oxaliplatin

This drug is a combination regimen of five agents: **tucatinib** (a selective, reversible small molecule tyrosine kinase inhibitor of HER2), **trastuzumab** (a recombinant humanized IgG1 monoclonal antibody that binds to the extracellular domain of HER2), **fluorouracil** (a pyrimidine antimetabolite that inhibits thymidylate synthase, blocking DNA synthesis), **leucovorin** (a reduced folate used to enhance the cytotoxic and antitumor effects of fluorouracil), and **oxaliplatin** (a platinum-based alkylating agent that cross-links DNA and inhibits replication and transcription). This multidrug combination targets the **HER2-positive pathway** in cancer, combining direct HER2 inhibition and chemotherapy. It is primarily under investigation for metastatic HER2-positive colorectal cancer and has been studied in the MOUNTAINEER-03 and related trials. Tucatinib is developed by Seagen, trastuzumab by Genentech/Roche, fluorouracil and leucovorin are generics, and oxaliplatin is originally by Sanofi.

Brand names

Tukysa (for tucatinib)Herceptin (for trastuzumab)None (for fluorouracil, generic)None (for leucovorin, generic)Eloxatin (for oxaliplatin)

Other names

TUKYSA + Herceptin + 5-FU + leucovorin + Eloxatin (regimen)HER2-targeted regimen with tucatinibHER-2-targeted regimen with tucatinibHER 2-targeted regimen with tucatinib