Peripheral blood CD4+/CD8+ T cell ratio may have potential for predicting the treatment response of durvalumab plus tremelimumab therapy (STRIDE) for unresectable hepatocellular carcinoma: Preliminary report

Abstract Background This preliminary study evaluated the clinical impact of peripheral blood T lymphocyte differentiation patterns to predict the treatment response to durvalumab plus tremelimumab therapy (a regimen termed STRIDE). Methods We investigated 21 patients with unresectable hepatocellular carcinoma (HCC) treated with STRIDE. The treatment response was evaluated 4–8 weeks after the initiation of STRIDE using the modified response evaluation criteria in solid tumors. The correlation between pretreatment peripheral blood T lymphocytes differentiation patterns, with a focus on the peripheral blood CD4+/CD8+ T cell ratio and response to STRIDE, was then investigated. Results Of the 21 patients, 5 (24%) had an objective response (OR). The median peripheral blood CD4+/CD8+ T cell ratio (CD4/8‐R) of the cohort was 1.4. A receiver operating characteristic curve showed the optimal cutoff value for predicting an OR to STRIDE determined by the Youden index to be 2.5. Of the seven patients with a CD4/8‐R ≥2.5, four (57%) had an OR. In contrast, of the 14 patients with a CD4/8‐R <2.5, only one patient (7%) had an OR. Finally, the OR rate (ORR) was significantly higher in the group with a CD4/8‐R ≥2.5 at the time of STRIDE initiation ( p = 0.025). Conclusions The peripheral blood CD4+/CD8+ T cell ratio is a potential predictive biomarker for the response to STRIDE therapy in HCC patients.