Serplulimab injection is an innovative anti-PD-1 mAb independently developed by Henlius. Up to now, Serplulimab have been approved for clinical trials in China, the United States, the European Union, as well as other countries and regions. A total of 10 immuo-oncology therapy clinical studies of Serplulimab have been conducted to evaluate its safety and efficacy in a variety of most common tumours that cover lung cancer, esophageal cancer, hepatocellular cancer, gastric cancer, head and neck cancer, etc. In March 2021, the pivotal phase 2 study of Serplulimab in patients with unresectable or metastatic microsatellite instability-high or mismatch repair-deficient (MSI-H/dMMR) solid tumours who have progressed on or been intolerant to standard therapies met the primary endpoint, demonstrating the good efficacy and safety of Serplulimab. As of now, the New Drug Application (NDA) of serplulimab injection for the treatment of MSI-H solid tumors has been accepted by the National Medical Products Administration (NMPA) and granted priority review.

Details of the two studies are as follows:

HLX10-010-MSI201

● Title

Efficacy and safety of HLX10, a novel anti-PD-1 antibody, in patients with previously treated unresectable or metastatic microsatellite instability-high or mismatch repair-deficient solid tumors: a single-arm, multicentre, phase 2 study.

● Co-Leading PI

Shukui Qin, MD, PhD, Chinese People's Liberation Army Cancer Center of Nanjing Bayi Hospital; Jin Li, MD, PhD, Shanghai East Hospital

● Form

Abstract and Poster 

● Abstract No.

2566

● Study Design

This single-arm, open-label, multi-centre, phase 2 study aimed to evaluate the efficacy, safety, and tolerability of HLX10 in patients with unresectable or metastatic microsatellite instability-high or mismatch repair-deficient solid tumours who have progressed on or been intolerant to standard therapies. Eligible patients were recruited to receive 3 mg/kg HLX10 every two weeks intravenously for up to 2 years until disease progression, unacceptable toxicity, or patient withdrawal. The primary efficacy endpoint was objective response rate (ORR) assessed by independent radiological review committee (IRRC) per RECIST v1.1.

● Results

1) Efficacy

a) Primary endpoint

108 patients were enrolled and 68 with MSI-H confirmed by central laboratory or study sites were included in the main efficacy analysis population. IRRC assessed ORR was 38.2% (95% CI: 26.7%, 50.8%; 2 complete response) in the main efficacy analysis population.

b) Secondary endpoints

Secondary efficacy endpoints included ORR assessed by investigators, duration of response (DoR), progression-free survival (PFS), and overall survival (OS). Median DoR, PFS and OS have not been reached.

2) Safety

The results demonstrated that HLX10 was safe and well-tolerated.

● Conclusion

HLX10 provides encouraging antitumor activity with a manageable safety profile in patients with MSI-H/dMMR solid tumors who have progressed on or been intolerant to standard therapies. As an effective tissue-agnostic treatment, HLX10 possesses the potential to improve patients’ clinical outcomes.

HLX10-011-CC201

● Title

Efficacy and safety evaluation of HLX10 (a recombinant humanised anti-PD-1 monoclonal antibody) combined with albumin-bound paclitaxel in patients with advanced cervical cancer who have progressive disease or intolerable toxicity after first-line standard chemotherapy: a single-arm, open-label, phase 2 study.

● Leading PI

Lingying Wu, MD, PhD, Cancer Hospital Chinese Academy of Medical Science

● Form

Abstract 

● Abstract No.

e17510

● Study Design

This is a single-arm, open-label, multi-centre, two-stage phase 2 study, aimed to evaluate the clinical efficacy of HLX10 in combination with albumin-bound paclitaxel for the treatment of advanced cervical cancer patients who have failed to respond to the first-line standard chemotherapy. Eligible patients were enrolled and given intravenous infusion of HLX10 (4.5 mg/kg) plus albumin-bound paclitaxel (260 mg/m2) every 3 weeks. The primary efficacy endpoint was objective response rate (ORR) assessed by independent radiological review committee (IRRC) per RECIST v1.1.

● Results

The stage one of this study was a safety run-in and preliminary efficacy exploration study. 21 patients were enrolled with an average Combined Positive Score (CPS) of 39.33. The ORR assessed by IRRC and investigators were 52.4% (95% CI: 29.8%, 74.3%) and 42.9% (95% CI: 21.8%, 66.0%), respectively. The results demonstrated that HLX10 was safe and well tolerated.

● Conclusion

Stage one results demonstrated a manageable safety profile and encouraging efficacy of HLX10 plus albumin-bound paclitaxel in advanced cervical cancer patients who have failed to respond to the first-line standard chemotherapy.