Immune-related adverse events predict responses to PD-1 blockade immunotherapy in hepatocellular carcinoma

Immune checkpoint blockade has demonstrated remarkable efficacy in hepatocellular carcinoma (HCC) but is also commonly accompanied by immune-related adverse events (irAEs). However, the association between irAEs and antitumor efficacy in HCC patients remains unknown. All patients with HCC treated with anti-PD-1 antibodies from July 2018 to November 2019 were analyzed and divided into different groups according to their irAEs' status. In total, 101 HCC patients, including 21 (20.8%) patients who presented with irAEs (irAEs⁺ ), were enrolled. Among the adverse events, rash (n = 9, 8.9%) was the most frequent irAE, followed by mucositis (n = 3, 3.0%) and thyroiditis (n = 3, 3.0%). Patients in the irAEs⁺ group showed a higher tumor response rate than those in the irAEs^- group (overall response rate: 28.6% vs 6.3%, P = .011; disease control rate: 85.7% vs 60.0%, P = .028). The median progression-free survival (PFS) times were 14.8 months in the irAEs⁺ group and 4.1 months in the irAEs^- group (P < .001). Further analysis based on the presence or absence of rash showed that the PFS of the patients in the irAEs⁺ /rash⁺ group was better than that of those in the irAEs⁺ /rash^- or irAEs^- group (all P < .05). Multivariate analysis showed that irAEs were an independent prognostic factor for PFS (hazard ratio [HR]: 0.22, P = .002). Thus, the occurrence of irAEs, especially rash, was associated with markedly improved PFS. Awareness of irAEs may help classify the subtype of HCC patients with an unprecedented survival benefit from anti-PD-1 antibodies.