Tissue and imaging biomarkers of response to neoadjuvant nivolumab or nivolumab plus ipilimumab in patients with resectable hepatocellular carcinoma.

Introduction: Perioperative immunotherapy has shown promise in some patients with early-stage hepatocellular carcinoma (HCC). This study examined tissue and imaging biomarkers associated with pathologic response in a phase II clinical trial in patients with resectable HCC.

Methods: Analysis included 18 patients with biopsy-proven resectable HCC treated with neoadjuvant nivolumab plus ipilimumab or nivolumab alone in a phase II clinical trial at MD Anderson Cancer Center (NCT03222076). Liver MRE (to measure tissue fibrosis) and biopsies (to evaluate immune activation markers) were obtained serially pretreatment and after completing neoadjuvant immunotherapy. A major pathologic response (MPR) was defined as tumor necrosis of more than 70%. Data comparing patients with MPR versus those without was summarized using descriptive statistics and compared using the Wilcoxon rank sum test.

Results: Patients with MPR after neoadjuvant immunotherapy tended to have larger tumors (mean 9.52 vs. 4.99 centimeters; p = 0.050). They had a significant reduction in tumor size post-treatment (14.67% reduction vs. 9.15% increase in size; p = 0.042) and a non-significant decrease in serum AFP (-24.20% vs -14.00%; p = 0.085). Further, patients with MPR had a greater increase in intratumoral expression levels of CD8 (26.92% vs -0.04%; p = 0.026), Granzyme B (15.56% vs -2.24%; p = 0.011), and PD-1 (20.17% vs 0.40%; p = 0.048) but not PD-L1 (7.69% vs 0.57%; p = 0.26). Tumor and liver fibrosis were comparable before and after neoadjuvant therapy in patients with MPR versus non-responders.

Conclusion: Changes in tumor size and immune cell infiltration and activation are candidate predictive markers of pathologic response to neoadjuvant immunotherapy in patients with resectable HCC.