Adjuvant immune checkpoint inhibitors and association with recurrence-free survival in postoperative hepatocellular carcinoma (PREVENT): A prospective cohort study

4119 Background: Adjuvant therapy may improve survival of patients with hepatocellular carcinoma (HCC) after curative resection, yet no such therapy is universally recommended. This study compared safety and efficacy outcomes between patients at high risk of recurrence who received different types of adjuvant therapy or no such therapy after hepatic resection for HCC. Methods: Recurrence-free survival (RFS), overall survival, and adverse events were compared among patients who received adjuvant immune checkpoint inhibitors (ICIs) alone, ICIs with tyrosine kinase inhibitors (TKIs), or no adjuvant therapy at our medical center between 13 March 2019 and 19 March 2022. In some analyses, patients who received adjuvant therapy were matched based on propensity scores to patients who did not, in order to reduce confounding due to baseline differences. This study was registered on ClinicalTrials.gov (NCT05221398). Results: Of the 492 patients in our final analysis, 410 (83.3%) received no adjuvant therapy, 50 (10.2%) received ICIs alone, and 32 (6.5%) received adjuvant ICIs and TKIs. During median follow-up of 23.3 months (IQR 15.6 to 31.1 months), HCC recurred in 221 (53.9%) of patients who received no adjuvant therapy, compared to 22 (44.0%) of patients who received ICIs and 18 (56.3%) of patients who received ICIs and TKIs. RFS was significantly longer among patients who received either type of adjuvant therapy (23.9 months, 95%CI 14.0-33.7) than among those who received none (16.8 months, 95%CI 13.2-20.3), and this difference remained significant after propensity score matching (HR 0.61, 95%CI 0.39-0.94, P = 0.033). However, overall survival was unaffected by either type of adjuvant therapy, even after propensity score matching. The rate of grade 3 or 4 adverse events was similar between the two types of adjuvant therapy. Conclusions: ICIs alone or with TKIs may improve RFS of patients at high risk of recurrence after curative resection. Clinical trial information: NCT05221398 .