1. Anti-cancer chemotherapy or biologic therapy if administered prior to the first planned dose of study medication (napabucasin or FOLFIRI) within period of time equivalent to the usual cycle length of the regimen. An exception is made for oral fluoropyrimidines (e.g. capecitabine, S-1), where a minimum of 10 days since last dose must be observed prior to the first planned dose of study medication. Standard dose of bevacizumab (5 mg/kg) may be administered prior to FOLFIRI infusion, per Investigator decision, for as long as permanent decision to include or exclude bevacizumab is made prior to patient randomization. Radiotherapy, immunotherapy (including immunotherapy administered for non-malignant diseaseneoplastic treatment purposes), or investigational agents within four weeks of first planned dose of study medication, with the exception of a single dose of radiation up to 8 Gy (equal to 800 RAD) with palliative intent for pain control up to 14 days before randomization.