Biomarker Development for Response Prediction by DNA Mutational Analysis

"Histological biopsy of the index lesion (a radiological measurable lesion on which biopsy is performed) at baseline, as well as when showing progressive disease. Histological biopsies will be subjected to DNA sequencing to assess the mutational profile, as well as to analysis of carboxylesterase activity."

Blood samples will be taken at baseline to determine patient's genetic background variation (germline DNA).

Blood samples will be taken for pharmacokinetic analysis of the active irinotecan metabolite (SN-38).

Patients who are being treated in Rotterdam will be subjected to blood draws for validation of the earlier developed midazolam phenotyping test (midazolam clearance test), which may be an indicator for pharmacokinetics of irinotecan.