Phase I/II trial of BMS-986,205 and nivolumab as first line therapy in hepatocellular carcinoma.

Background: Indoleamine-2,3-dioxygenase (IDO) helps orchestrate immune suppression and checkpoint inhibitor resistance in hepatocellular carcinoma (HCC). BMS-986,205 is a novel oral drug that potently and selectively inhibits IDO. This Phase I/II study evaluated the safety and tolerability of BMS-986,205 in combination with nivolumab as first-line therapy in advanced HCC.

Methods: Adults with untreated, unresectable/metastatic HCC received BMS-986,205 at two dose levels (50-100 mg orally daily) in combination with fixed dose nivolumab (240mg/m² IV on Day 1 of each 14-day cycle). The primary objective was to determine the safety and tolerability of this combination; secondary objectives were to obtain preliminary efficacy.

Results: Eight patients received a total of 91 treatment cycles in the dose escalation phase. All patients were Child Pugh A and 6 patients had underlying viral hepatitis. In the 6 evaluable patients, no dose-limiting toxicities (DLTs) were observed. The most common treatment-related adverse events (TRAEs) were aspartate transaminase (AST) and alanine transaminase (ALT) elevation (3 patients) and diarrhea, maculopapular rash and increased alkaline phosphatase (2 patients each). Grade 3 events were diarrhea and AST elevation (1 patient), and hyperglycemia and pancreatitis requiring treatment discontinuation (1 patient). No grade 4-5 events occurred. Partial response was observed in 1 patient (12.5%) and stable disease in 3 patients (37.5%), yielding a disease control rate of 50%. Median PFS was 8.5 weeks; median OS was not reached.

Conclusion: Combination BMS-986,205 and nivolumab showed a manageable safety profile with durable benefit as first-line therapy in a meaningful subset of advanced HCC patients.