A Study of Tucatinib With Trastuzumab and mFOLFOX6 Versus Standard of Care Treatment in First-line HER2+ Metastatic Colorectal Cancer (MOUNTAINEER-03)

Overview

About this study

The purpose of this study is 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 test 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). 

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • 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.
  • Participant has rat sarcoma viral oncogene homolog wild-type (RAS WT) disease as determined by local or central testing. For central RAS analysis, tissue sample must be analyzed within 1 year of biopsy date.
  • Radiographically measurable disease per RECIST v1.1 with:
    • At least one site of disease that is measurable and that has not been previously irradiated, or
    • If the participant has had previous radiation to the target lesion(s), there must be evidence of progression since the radiation
  • Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
  • CNS Inclusion - based on contrast brain magnetic resonance imaging, participants may have any of the following:
    • No evidence of brain metastases
    • Previously treated brain metastases which are asymptomatic

Exclusion Criteria:

  • Prior systemic anticancer therapy for colorectal cancer (CRC) in the 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
  • Ongoing Grade 3 or higher neuropathy
  • GI perforation within 12 months of enrollment

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 07/03/2024. Questions regarding updates should be directed to the study team contact.

 

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Zhaohui Jin, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

Tanios Bekaii-Saab, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

More information

Publications

Publications are currently not available
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CLS-20535897

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