This study is being done to find out if tucatinib with other cancer drugs works better than standard of care to treat participants with HER2 positive colorectal cancer. This study will also determine what side effects happen when participants take this combination of drugs. A side effect is anything a drug does to the body besides treating your disease.
Participants in this study have colorectal cancer that has spread through the body (metastatic) and/or cannot be removed with surgery (unresectable).
Participants will be assigned randomly to the tucatinib group or standard of care group. The tucatinib group will get tucatinib, trastuzumab, and mFOLFOX6. The standard of care group will get either:
* mFOLFOX6 alone, * mFOLFOX6 with bevacizumab, or * mFOLFOX6 with cetuximab mFOLFOX6 is a combination of multiple drugs. All of the drugs given in this study are used to treat this type of cancer.
Histologically and/or cytologically confirmed adenocarcinoma of the colon or rectum which is locally advanced unresectable or metastatic
Able to provide the most recently available formalin-fixed paraffin-embedded (FFPE) tumor tissue blocks (or freshly sectioned slides) obtained prior to treatment initiation to a central laboratory
If archival tissue is not available, a newly-obtained baseline biopsy of an accessible tumor lesion is required within 35 days prior to start of study treatment
HER2+ disease as determined by a tissue based assay performed at a central laboratory.
Prior systemic anticancer therapy for colorectal cancer (CRC) in the locally advanced unresectable or metastatic setting; note that participants may have received a maximum of 2 doses of mFOLFOX6 in the locally advanced/unresectable or metastatic setting prior to randomization.
Note: May have received chemotherapy for CRC in the adjuvant setting if it was completed >6 months prior to enrollment
Radiation therapy within 14 days prior to enrollment (or within 7 days in the setting of stereotactic radiosurgery)
Previous treatment with anti-HER2 therapy
Seagen, a wholly owned subsidiary of Pfizer
Lead sponsor