Real-world cohort study of PD-1 blockade plus lenvatinib for advanced intrahepatic cholangiocarcinoma: effectiveness, safety, and biomarker analysis

Background: In clinical practice, some patients with advanced intrahepatic cholangiocarcinoma (ICC) cannot tolerate or refuse chemotherapy due to the toxicity, necessitating alternative treatments. PD-1 blockade combined with lenvatinib showed promising results in phase II studies with small sample size, but there is a lack of data on the routine use with this regimen. This study aimed to evaluate the effectiveness and safety of the regimen in patients with advanced ICC, and to identify predictors for treatment response and prognosis.Methods: We conducted a retrospective cohort study of patients treated with PD-1 inhibitors plus lenvatinib for advanced ICC between July 2017 and August 2022. The study endpoints were progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety. Biomarker analysis for CA19-9 and PD-L1 expression was performed. Exploratory analysis for genetic alternation was conducted.Results: The study included 103 patients. It demonstrated a median PFS of 5.9 months and a median OS of 11.4 months. ORR was 18.4% and DCR was 80.6%. The incidence of grade 3 or 4 adverse events was 50.5%. Positive PD-L1 expression (TPS >= 1%) was associated with higher ORR (P = 0.013) and prolonged PFS (P = 0.023). Elevated CA19-9 (> 37 U/ml) was associated with decreased ORR (P = 0.019), poorer PFS (P = 0.005) and OS (P = 0.034). Patients with IDH1 mutations exhibited a favorable response to the treatment (P = 0.011), and patients with TP53 mutations tended to have worse OS (P = 0.031).Conclusions: PD-1 blockade plus lenvatinib is effective and safe in routine practice. PD-L1 expression and CA19-9 level appear to predict the treatment efficacy. IDH1 mutations might indicate a better treatment response.