Research Studies

- Clinical and histopathological diagnosis of metastatic colorectal cancer. - GCC positive metastatic disease as determined by IHC from a new biopsy of a proposed target lesion. Positivity on staining of archival tissue is not adequate. GCC positivity is defined as >70% of cells staining for GCC. - Received prior therapy with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy in the metastatic setting (or palliative therapy within 12 months of adjuvant therapy), an anti-VEGF biological therapy if not contraindicated, and if RAS wild-type, an anti-EGFR therapy in a manner consistent with NCCN guidelines. Treatment must have been discontinued for disease progression or intolerance to therapy (refractory). - Have at least two extracranial measurable target lesions according to the RECIST 1.1 standard. One target lesion must be amenable to biopsy via percutaneous core needle. Lung lesions as the intended target lesion for biopsy are only allowed if deemed safe after consultation with the Medical Monitor. - Lesions amenable to radiotherapy or palliative radiotherapy (e.g., bone metastases or metastases causing nerve impingement) should be treated > 4 weeks prior to enrollment and subjects must be fully recovered from the effects of radiation. - NOT permitted: Subjects with unresectable or metastatic microsatellite instability-high or mismatch repair deficient tumors unless they are deemed as failing prior checkpoint inhibitor therapy. - NOT permitted: brain metastases.