201P - A phase II study of serplulimab (a programmed death-1 inhibitor) with or without HLX04 (a bevacizumab biosimilar) for the treatment of advanced hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) accounts for around 90% of liver cancer cases, and there are still significant therapeutic challenges. This study aimed to assess the safety and preliminary efficacy of serplulimab, a novel programmed cell death-1 inhibitor, with or without the bevacizumab biosimilar HLX04 in patients with advanced HCC.

Methods

Patients with advanced HCC who failed prior systemic therapy received serplulimab 3 mg/kg plus HLX04 5 mg/kg (group A), serplulimab 3 mg/kg plus HLX04 10 mg/kg (group B), or serplulimab 3 mg/kg monotherapy (group C). Patients with previously untreated advanced HCC were enrolled in group D and given serplulimab 3 mg/kg plus HLX04 10 mg/kg. All treatments were administered intravenously every 2 weeks. The primary endpoint was safety.

Results

This open-label, multicentre phase 2 study was conducted in China; 28 hospitals enrolled patients. Results of group A and B have been previously published; here we present results of group C and D. As of 7 February 2023, 21 and 61 patients were enrolled in group C and D. The median follow-up duration was 26.0 and 25.5 months, respectively. 10 (47.6%) patients in group C and 29 (47.5%) in group D reported grade ≥3 treatment-emergent adverse events. 1 (4.8%) patient in group C died from treatment-related hepatic failure; 1 (1.6%) in group D died from treatment-related hepatic failure and disease progression. As assessed by an independent radiological review committee (IRRC) per RECIST v1.1, the objective response rate was 4.8% (95% confidence interval [CI] 0.1–23.8) in group C and 27.9% (95% CI 17.1–40.8) in group D. IRRC-assessed median progression-free survival was 1.8 months (95% CI 1.4–2.8) and 7.3 months (95% CI 2.8–11.0) in group C and D, respectively. Median overall survival was 16.0 months (95% CI 3.6–not evaluable [NE]) in group C and 19.1 months (95% CI 14.3–NE) in group D.

Conclusions

In the first-line and subsequent-line settings, serplulimab plus HLX04 and serplulimab monotherapy, respectively, showed a manageable safety profile together with encouraging efficacy in patients with advanced HCC.

Clinical trial identification

NCT03973112 (released on 4 June 2019).

Editorial acknowledgement

Editorial assistance was provided by Shiqi Zhong, Zhi Hao Kwok, and Chen Hu of Shanghai Henlius Biotech, Inc.

Legal entity responsible for the study

Shanghai Henlius Biotech, Inc.

Funding

Shanghai Henlius Biotech, Inc.

Disclosure

X. Hou, Q. Wang, J. Zhu: Financial Interests, Personal, Full or part-time Employment: Shanghai Henlius Biotech, Inc. All other authors have declared no conflicts of interest.