Impact of baseline and concomitant corticosteroid therapy on the outcomes of hepatocellular carcinoma treated with immune checkpoint inhibitor therapy

531 Background: The impact of corticosteroid treatment (CT) on the efficacy of immune checkpoint inhibitors (ICI) in hepatocellular carcinoma (HCC) is undefined. We evaluated whether CT administered at baseline (bCT) or concurrently to ICI (cCT) influences clinical outcomes of HCC patients treated with ICI. Methods: This retrospective, multi-center observational study was conducted across 9 tertiary academic referral centers collected 341 HCC patients who received ICI across 3 continents between January 1, 2016 and April 1, 2019. Outcome measures included overall (OS) and progression-free survival (PFS) calculated from time of ICI commencement and overall response rates (ORR) defined by Response Evaluation Criteria in Solid Tumors (v1.1) on 6-8 weekly periodic restaging. Results: Of 331 eligible patients, 254 (76%) had BCLC-C stage HCC and received mostly PD(L)-1 ICI monotherapy (n=250, 85%). Median OS was 12.1 months (95%CI 9.2-15.0 months) and median PFS was 8.1 months (95%CI 6.3-10 months). In total 81 patients (24%) received >10 mg prednisone equivalent daily either as bCT (n=15, 4%) or cCT (n=66, 20%). Indications for CT included procedure/prophylaxis (n=37, 45%), management of irAE (n=31, 37%), cancer-related symptoms (n=5, 2%) or comorbidities (n=8, 3%). Neither overall CT, bCT nor cCT predicted for worse OS, PFS nor ORR in uni- and multi-variable analyses (p>0.05). CT for cancer-related indications predicted for shorter PFS (2.4 vs. 11.3 months, p=0.01), OS (4.5 vs. 12.8 months, p=0.05) and reduced ORR (p=0.03) compared to cancer-unrelated indications. Conclusions: This is the first study to demonstrate that neither bCT nor cCT appear to influence response and OS following ICI in HCC. Worse survival and ORR in CT recipients for cancer-related indications appears driven by the poor prognosis associated with symptomatic HCC.