Treatment-related toxicity and improved outcomes with immune checkpoint inhibitors in patients with hepatocellular carcinoma.

Abstract

4085 Background: The development of treatment-related adverse events (trAE) correlates favorably with clinical outcomes in multiple studies of patients receiving immune checkpoint inhibitors (ICI), however, this relationship is undefined in patients with hepatocellular carcinoma (HCC). This retrospective multi-center study aimed to examine whether trAEs are prognostic in HCC. Methods: We established an international consortium of 10 tertiary-care referral centers located in Europe (n = 67), United States (US, n = 248) and Asia (n = 42) to test whether the development of clinically significant trAE (i.e. graded >2, trAE2) predicted for improved overall (OS), progression-free survival (PFS), and overall response rates (ORR) following ICI, and subsequently validated this association in a separate cohort of 406 HCC patients receiving ICI therapy as part of international clinical trials submitted to the US Food and Drug Administration (FDA) in support of marketing applications. Results: In a multi-institutional cohort of 357 patients, 274 (77%) with Barcelona Clinic Liver Cancer (BCLC) stage C HCC mostly treated with ICI monotherapy (n = 304, 85%), trAE were reported in 146 patients (41%). Development of trAE2 were associated with longer OS (23.3 versus 12.2 months) and PFS (8.6 months versus 3.7 months). After adjusting for viral aetiology, gender, presence of cirrhosis, Child-Pugh class, BCLC stage, AFP levels, ECOG-PS, ICI regimen (mono/combination therapy) and receipt of corticosteroid therapy, trAE2 were confirmed predictors of improved OS (HR 0.55; 95%CI:0.34-0.88) and PFS (HR 0.51; 95%CI: 0.35-0.74). TrAE2 were associated with higher ORR (27% versus 16%) from ICI. The association between trAE2 and patients’ OS (HR 0.49; 95%CI:0.34-0.70) and PFS (HR 0.43; 95%CI:0.32-0.59) was also observed in the FDA dataset. After a 6-weeks landmark selection, trAE2 were confirmed to be associated with improved PFS (HR 0.59; 95%CI:0.39-0.87); the additional analysis adjusted for tumour response and duration of treatment within the FDA cohort further confirmed the association with longer PFS (HR 0.67; 95%CI: 0.47-0.94). Conclusions: Development of trAE2 may correlate with response and survival in patients with HCC receiving ICI, a clinical setting where the lack of biomarkers still represents an unmet need. Prospective studies aimed at understanding the underlying immunologic foundations of such relationship are warranted to identify predictive biomarkers of toxicity and response.