Downstaging Hepatocellular Carcinoma with Checkpoint Inhibitor Therapy Improves Access to Curative Liver Transplant

Purpose: Liver transplantation is curative for hepatocellular carcinoma (HCC). Checkpoint inhibitor therapy (CPIT) has been used in unresectable HCC, but recent advances have demonstrated CPIT as an innovative method of downstaging advanced HCC with the caveat that CPIT prior to transplantation has risks including irreversible graft rejection. We report the outcomes of Mayo Clinic Arizona patients who underwent downstaging with CPIT. Methods: This retrospective chart review was conducted for Mayo Clinic Arizona patients who were diagnosed with HCC who underwent downstaging with CPIT with the goal of meeting criteria for transplantation. Results: We present nine cases with HCC outside Milan who underwent CPIT. Four received a transplant; one was delisted due to his exceptional therapeutic response. All received liver-directed therapy. Peak alpha-fetoprotein pre-CPIT ranged from 8–29,523 ng/mL, which decreased to 2.2–19.6 ng/mL on CPIT. CPIT included atezolizumab/bevacizumab, ipilimumab/nivolumab, nivolumab, and pembrolizumab; one patient received two regimens. CPIT was held prior to transplant at a median of 3 months. Three patients received methylprednisolone for immunosuppression induction; one received thymoglobulin. One patient developed acute cellular rejection at 5 weeks, 9 weeks, and 5 months post-transplant; given the late onset, these were not attributed to CPIT and were successfully treated. During an average follow-up of 16.5 months, no tumor recurrence has occurred. Conclusion: We describe nine patients with HCC outside Milan with inadequate response with liver-directed therapy, who achieved marked responses with CPIT, allowing for consideration of successful liver transplantation. Our case series supports the consideration of locoregional therapies and CPIT for downstaging to within transplant criteria.