Clinical Indicators for Long-Term Survival with Immune Checkpoint Therapy in Advanced Hepatocellular Carcinoma

Introduction: Patients with advanced hepatocellular carcinoma have a dismal prognosis; only a subset of patients with advanced HCC will benefit from treatment with immunotherapy. We searched for clinical characteristics predicting exceptional long-term survival in HCC patients treated with immune checkpoint inhibitors.

Methods: We compared clinical characteristics of 59 patients with advanced hepatocellular carcinoma treated with immunotherapy with and without locoregional therapy between 2013-2019. We compared patients who lived less than 12 months with patients who lived more than 3 years. Traits of short-term (31 patients) and long-term (5 patients) survivors were compared. Patients who died between 12 months and 3 years of starting treatment on protocol were not included in the analysis.

Results: Two out of five patients (40%) in the long-term survival group had a partial response (PR) or a complete response (CR) per the modified Response Evaluation Criteria in Solid Tumors (mRECIST), while, of the 31 patients in the short-term survival group, only 2 (6.5%) had a CR or PR. Two of the 5 patients with a long-term survival had immune-related adverse events grade 3 or 4 (IrAEs-3/4). None of the patients in the short-term survival group had IrAEs-3/4. The patients, who presented with IrAEs-3/4, which included colitis and adrenal insufficiency, continued to have a response off treatment. The median overall survival (OS) was 11.8 months (95% CI: 7.8-15.4 months), with a 12-month OS of 46.6% (95% CI: 33.4-58.8%) and a 3-year OS of 12.5% (95% CI: 5.0-23.7%).

Conclusion: We found a possible association between immune-related adverse events grade 3 and 4 and long-term survival in patients with advanced HCC. The cases in our analysis represent extraordinary defiance of the usual predicted dismal course of advanced HCC.