Long-term survival of combined ablation therapy and tremelimumab with or without durvalumab in advanced hepatocellular carcinoma.

Abstract

e16689 Background: Immune checkpoint inhibitor therapy has recently been approved for the treatment of patients with Hepatocellular Cancer (HCC). Data on long-term survival is lacking and the predictors of good outcomes are unknown. The combination of locoregional therapies (transarterial chemoembolization or radiofrequency ablation) plus tremelimumab (trem) with or without durvalumab (durva) was studied in patients with advanced HCC. We report the long-term survival and analyze predictors of good response in two trials of immune checkpoint and ablation treatment in advanced HCC. Methods: Adult patients (pts) with pathologically confirmed HCC with advanced or sorafenib refractory disease who satisfied the eligibility criteria were enrolled in the studies (NCT02821754, NCT01853618). They received treatment with trem, 10 mg per kilogram every 4 weeks for six doses followed by 3 monthly infusions (23 pts) or trem 75 mg flat dose every 28 days for four doses and then durva 1500 mg flat dose every 28 days (35 pts). Subtotal radiofrequency or chemoablation was done on day 36. Results: The average overall survival in the 58 pts was 10.1 months (range 0.9 to 74.2 months); 41.6% were alive at 12 months and 5.5 % were alive at 61 months. A select group of patients had exceptional overall survivals up to 67 months. Predictors of improved overall survival included the presence of higher grade immune related (irAEs) (OR 0.235, p = 0.075) and a partial or stable disease response per RECIST. No new late toxic effects were noted during this long term follow up. Conclusions: Impressive overall survival times of up to 68.8 months were observed with ICI and subtotal ablation in patients with advanced HCC; the presence of irAEs and the tumor response per RECIST may be predictive of better overall survivals. To our knowledge this has not been previously reported in the literature. Clinical trial information: NCT02821754,NCT01853618 .