Optimization for Regorafenib in HCC

In this study, the investigators intend to evaluate the regorafenib ReDOS strategy to optimize the dose of regorafenib in patients with unresectable HCC (uHCC) who progressed during or after the first-line systemic treatment. This would allow improving the tolerability profile for patients such as those not selected based on prior sorafenib tolerability. The proposed regorafenib dosing escalation strategy for subjects randomized to the Arm A starting 80 mg/day dose for one week (Cycle 1, Week 1) is, if absent significant drug-related toxicities, to escalate to 120 mg/day for another week (Cycle 1, Week 2), and then, again if absent significant related toxicities, escalate to a total dose of 160 mg/day (Cycle 1, Week 3) followed by a week-long break (Cycle 1, Week 4). Arm B, the comparative arm, will include a standard dose/schedule regorafenib of a 160 mg/day starting on Cycle 1, Day 1. The primary goal of this Arm is compare whether, or not, an 80 mg/day starting dose of regorafenib that escalates weekly by 40 mg until 160 mg/day is non-inferior to the FDA approved labeling 160 mg starting dose of regorafenib in terms of Overall Survival (OS) in HCC subjects. The investigators will also compare the proportions of patients in each arm who complete two cycles of treatment and who intend to continue to a third cycle if no tumor progression is noted on the 8-week disease scan. Other outcomes such as Quality of Life measures, and toxicity profile with a focus on regorafenib related toxicities such as hand-foot skin reaction will also be assessed. Patients will be randomized 1:1 to either Arm A receiving the Cycle 1 Week-1 80 mg daily dose or Arm B the standard FDA labeling 160 mg daily starting dose, with subsequent dose adjustments as needed. Patients with unacceptable toxicities at the 80 mg dose may be considered for further dose reduction but will no longer be included in the overall survival analysis. After the conclusion of Cycle 2 (Week 8 of treatment), if toxicities have sufficiently resolved, re-escalation is allowed 40 mg at a time every four weeks to a maximum of 160 mg/day at the discretion of the treating investigator. Patients will continue treatment until progression, unacceptable adverse events, or patient refusal. Treatment will then be discontinued, and the patient will go to event monitoring. Additionally, a site-optional and subject-optional sub-study collecting blood serum samples at the Screening Visit for "hold and store" for future analysis of CD14, CD15, and CD16 cells as well as other potential biomarkers to be determined.