The 24th Annual Meeting of Chinese Society of Clinical Oncology (CSCO) is held online and in-person from 25th to 29th September 2021. In this meeting, Henlius releases phase 2 study results of serplulimab (HLX10, novel anti-PD-1 antibody), in patients with previously treated unresectable or metastatic microsatellite instability-high or mismatch repair-deficient (MSI-H/dMMR) solid tumours in an oral presentation. In April, the New Drug Application (NDA) of serplulimab for the treatment of MSI-H solid tumours was accepted by the National Medical Products Administration (NMPA) and granted priority review, which is expected to be approved in the first half of 2022. What's more, the NDA of serplulimab for the treatment of squamous non-small cell lung cancer is also under review.
With the "Combo+Global" strategy, serplulimab has been approved for clinical trials in China, the United States, the European Union, as well as other countries and regions. To evaluate the safety and efficacy of serplulimab, Henlius has conducted 10 immuno-oncology therapy clinical studies covering cancers with high incidence rates, including lung cancer, esophageal cancer, hepatocellular cancer, gastric cancer, head and neck cancer, etc. Up to date, about 2300 patients have been enrolled worldwide, proving that the quality of serplulimab has built trust in foreign markets.
Details of this study are as follows:
Title: Phase 2 study of HLX10, a novel anti-PD-1 antibody, in patients with previously treated unresectable or metastatic microsatellite instability-high or mismatch repair-deficient solid tumours (ID: 9951)
Leading PI: Shukui Qin, Chinese People's Liberation Army Cancer Center of Nanjing Bayi Hospital; Jin Li, Shanghai East Hospital, Tongji University
Form: Oral presentation
Presenter: Ye Guo, Shanghai East Hospital, Tongji University
Time: 2021.09.26 17:15–17:23, Parallel Session 6, Immunotherapy session
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.
By cut-off date of 9 January 2021, 108 patients were enrolled. 68 patients with MSI-H confirmed by central laboratory or study sites were included in the main efficacy analysis population (MEAP) and 42 were included in the special-interest efficacy analysis population (SIEAP; including colorectal cancer patients who had received treatment of the three drugs [fluorouracils, irinotecan and oxaliplatin], third or later line patients with gastric cancer and second or later line patients with other tumours). The median follow-up duration was 7.7 months (range: 1.1–16.4) in MEAP, and 7.3 months (range: 1.1–16.4) in SIEAP. IRRC assessed ORR were 38.2% (95% CI: 26.7, 50.8; 2 CR, 24 PR) in MEAP and 31.0% (95% CI: 17.6, 47.1; 1 CR, 12 PR) in SIEAP.
Secondary efficacy endpoints included ORR assessed by investigators, progression-free survival (PFS), overall survival (OS), and duration of response (DoR). In MEAP, median PFS, OS and DoR have not been reached (NR); the 12 months PFS rate assessed by IRRC was 61.9% (95% CI: 49.0, 72.5), 12 months OS rate was 81.2% (95% CI: 67.8, 89.4), 12 months DoR rate assessed by IRRC was 95.7% (95% CI: 72.9, 99.4). In SIEAP, median PFS assessed by IRRC was 4.2 months (95% CI: 2.2, NR); median DoR and OS have not been reached.
The results demonstrated that HLX10 was safe and well-tolerated.
HLX10 provides encouraging antitumour activity with a manageable safety profile in patients with MSI-H solid tumours who have progressed on or been intolerant to standard therapies. As an effective tissue-agnostic treatment candidate, HLX10 possesses the potential to improve patients’ clinical outcomes.