Previous treatment with regorafenib AND TAS- (this applies to phase II only; if patients have previously received either regorafenib OR TAS-, they must be able to receive the alternate regimen if randomized to the standard of care arm)
Prior treatment with TAS-
Participants who have previously received TAS-
Previous use of TAS-, S-, and -FU drugs;
Prior therapy with TAS-
Contraindications to TAS-\r\n* Absolute neutrophil count < ,/ul\r\n* Platelet count < ,/ul\r\n* Allergy or intolerance to TAS-
Any medication administered within  weeks prior to st dose of TAS that is known to affect QT interval or arrhythmogenic
Received prior treatment of TAS
Has known hypersensitivity to TAS- or its components.
Prior treatment with TAS- or regorafenib
Prior MEK inhibitor or prior TAS- therapy
Previous treatment with TAS- or TMZ
Has previously received TAS-.
Any of the following treatments, within the specified time frame, prior to the first dose of TAS:
Prior treatment with TAS or known hypersensitivity to any of its inactive ingredients or drugs similar in class
Known sensitivity to TAS-, CPT-, Bevacizumab, or their components