Recently, Volume 5, Issue 10 of Med, a flagship medical journal by Cell Press, has been published online. The front cover of the issue features HLX22-GC-201, a phase 2 study of HLX22, an innovative anti-HER2 monoclonal antibody (mAb), in combination with HANQUYOU (HLX02, trastuzumab, trade name: HERCESSI™️ in the U.S., Zercepac® in Europe) and chemotherapy for the first-line treatment of HER2-positive advanced gastric/gastroesophageal junction (G/GEJ) cancer. This study was led by Professor Jin Li from Shanghai GoBroad Cancer Hospital.
"Gastric cancer ranks as the fifth most prevalent cancer globally and the fourth leading cause of cancer-related mortality. The prognosis for advanced gastric cancer is poor, underscoring the urgent need for more effective treatment strategies. In this issue of Med, Li et al. conducted a phase 2 clinical study to explore the efficacy and safety of combining two different anti-HER2 antibodies plus XELOX as first-line therapy for patients with HER2-positive advanced gastric cancer." The editors emphasized the urgency of treating advanced gastric cancer and the potential benefits of HLX22 combined therapy. "The study reveals that the treatment regimen significantly extended progression-free survival and improved antitumor response in these patients, with manageable safety profiles, supporting the clinical benefits of dual HER2 blockade."
Additionally, the issue included an accompanying Viewpoint article, which highlighted that HLX22-GC-201 demonstrated encouraging objective response and progression-free survival, and future development of this combination in HER2+ G/GEJ cancer is worth continued attention [1].
HLX22 is an innovative anti-HER2 mAb introduced from AbClon, Inc. and further investigated and developed by Henlius. HLX22 can bind to HER2 subdomain IV at a binding site different from that of trastuzumab, which allows simultaneous binding of HLX22 and trastuzumab to HER2 dimers (HER2 homodimer and HER2/EGFR heterodimer) on tumour cell surface, thereby promoting the internalisation and HER2 dimer degradation. Pre-clinical studies showed that the co-treatment with HLX22 and trastuzumab inhibited cell proliferation induced by epidermal growth factor (EGF) and histidine-rich glycoprotein 1 (HRG1) and led to enhanced antitumour activity in vitro and in vivo. A phase 1 clinical trial of HLX22 demonstrates that HLX22 was well tolerated and had a favorable safety profile [2].
HLX22-GC-201 is a two-stage study aims to compare the efficacy and safety of HLX22 versus placebo in combination with trastuzumab injection (HLX02) and XELOX, as first-line therapy for HER2-positive locally advanced or metastatic gastric cancer patients. Stage 1 was a safety run-in stage while stage 2 was a randomised, double-blind, multi-centre, phase 2 study. Stage 2 was further divided into two parts. In part 1, eligible patients were randomised 1:1:1 to receive HLX22 (group A: HLX22, 25mg/kg; group B: HLX22, 15mg/kg) in combination with HLX02 and XELOX, or placebo in combination with HLX02 and XELOX (group C). The primary endpoints include progression-free survival (PFS) and objective response rate (ORR) assessed by independent radiological review committee (IRRC) per RECIST v1.1. The secondary objectives are to evaluate other efficacy endpoints, safety and tolerability. The results showed that the addition of HLX22 to HLX02 (trastuzumab) plus chemotherapy as first-line therapy improved efficacy in HER2-positive G/GEJ cancer patients with manageable safety.
Results from HLX22-GC-201 were first presented at the 2024 American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI). Updated results and study data and were subsequently presented at the 2024 ESMO Gastrointestinal Cancers Congress (ESMO GI) and on Med, respectively, which validated the reliability of the results and further enhanced the impact of the study in the academic community.
Investigational new drug (IND) applications have received regulatory approvals in China, the U.S. and Japan for a phase 3 international multi-centre clinical study of HLX22 in combination with trastuzumab and chemotherapy for the first-line treatment of HER2-positive advanced gastric cancer. Moving forward, Henlius will actively improve efficiency through innovations, with a particular focus on addressing the unmet medical needs, and efficiently promote the global clinical development of HLX22, so as to provide more high-quality and affordable therapies for patients worldwide.
【Reference】
[1] Strickland MR, Klempner SJ. Dual HER2 inhibition: Is two better than one?. Med. 2024;5(10):1191-1193. doi:10.1016/j.medj.2024.07.008
[2] Zhu X, Ding Y, Wang Q, Yang G, Zhou L, Wang Q. HLX22, an anti-HER-2 monoclonal antibody, in patients with advanced solid tumors overexpressing human epidermal growth factor receptor 2: an open-label, dose-escalation, phase 1 trial. Invest New Drugs. 2023;41(3):473-482. doi:10.1007/s10637-023-01338-7