Abstract: Objective The aim of this study was toinvestigate theefficacy of sintilimab in combination with lenvatinib in treatment ofpatients with advanced primary liver cancer (aPLC). Methods A total of 95 patients with aPLC were encountered in our hospital between July 2022 and December 2024, and were randomly assigned to receivelenvatinibin 47 cases in control or receive lenvatinib and sintilimab combination in another 48 cases in observation for 4 cycles of the regimen. Patients were followed-up for one to two and half years. Serum alpha fetoprotein (AFP), protein induced by vitamin K absence or antagonist-II ( PIVKA-II) and lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) levels were measured by using ELISA, and peripheral blood Tlymphocyte subsets were detected by flow cytometry. Results Objective remission rate and disease control rate in the observation group were 45.8% and 87.2%, both significantly higher than 23.4% and 70.2% (P<0.05)in the control group; after treatment, serum PIVKA-II, AFP and AFP-L3 levels in the observation group were all much lower than in the control (P＜0.05); percentage of CD4⁺ cells and CD4⁺/CD8⁺ cell ratio were both significantly higher than in the control group (P＜0.05); by end of follow-up, 35 patients (72.9%)in the observation and25 patients (53.2%) in the control survived (P＜0.05), with mean progress-free survival of 16.5 mon, much longer than 9.4 mon (P＜0.05) in the control; one-year survival rate in the observation was 89.6%, much higher than 72.3%(P＜0.05) in the control group. Conclusion Combination of sintilimaband lenvatinibin dealing with patients with aPLC could obtain promising clinical benefits, with prolonged short-term survival rate, which might related to improved body immune functions and inhibition of tumor growth.

Key words: Hepatoma, Sintilimab, Lenvatinib, Therapy