Recently, Henlius announced that the clinical trial notification (CTN) for phase 3 international multicenter clinical study of Henlius’ novel anti-HER2 mAb, HLX22, in combination with trastuzumab and chemotherapy for the first-line treatment of HER2-positive advanced gastric cancer has been permitted by Japan’s Pharmaceuticals and Medical Devices Agency (PMDA). The investigational new drug (IND) applications of this study have previously approved by National Medicinal Products Administration (NMPA) and the United States Food and Drug Administration (FDA). As of now, no similar dual HER2 blockade therapy for the treatment of HER2-positive gastric cancer has received approval for commercialization globally.
Until now, gastric/gastroesophageal junction (G/GEJ) cancer still constitutes a major global health problem. Globally, there were around 1 million cases in 2022 [1]. While in Japan, the incidence and mortality of G/GEJ rank third among all malignant tumors, and, in 2022, there were 127,000 new cases and 44,000 deaths [1]. G/GEJ cancer generally carries a poor prognosis since it is often diagnosed at an advanced stage, with a 5-year relative survival rate of only 6% [2,3]. The reported rates of HER2 positivity in patients with gastric cancer range from 12% to 23%, and the prognosis for patients with HER2-positive disease used to be even worse than those with HER2-negative disease [2-4]. Currently, for patients with HER2-positive locally advanced/metastatic G/GEJ cancer, the current standard first-line treatment is trastuzumab plus chemotherapy. Immunotherapies are recommended to be added for tumours with PD-L1 expression levels by CPS (Combined Positive Score) of greater than 1. However, the effectiveness and prognosis for these treatments need to be further improved [5].
HLX22 is an innovative anti-HER2 mAb that was introduced from AbClon, Inc. and further researched and developed by Henlius. HLX22 can bind to HER2 subdomain IV at a different binding site from trastuzumab, which allows the simultaneous binding of HLX22 and trastuzumab to HER2. Pre-clinical studies have shown that the combination therapy of HLX22 and trastuzumab inhibits the cell proliferation induced by epidermal growth factor (EGF) and Histidine-Rich Glycoprotein 1 (HRG1) and enhance the antitumor activity in vitro and in vivo. The phase 1 clinical trial of HLX22 demonstrates that HLX22 is well tolerated and has good safety profiles. In January 2024, results from the phase 2 study of HLX22 combined with HANQUYOU (trastuzumab for injection, HLX02, HERCESSI™ in the U.S. and Zercepac® in Europe) and chemotherapy for the first-line treatment of HER2-positive G/GEJ cancer was presented at the 2024 ASCO Gastrointestinal Cancers Symposium (ASCO GI), ESMO Gastrointestinal Cancers Congress (ESMO GI), and MED, a flagship clinical and translational research monthly journal by Cell Press, which showed that adding HLX22 to HLX02 (trastuzumab for injection) + XELOX improved survival and antitumor response in patients with HER2-positive G/GEJ cancer in the first-line setting, with a manageable safety profile [7-9].
Moving forward, the company will continue to uphold a patient-centric approach, focus on unmet medical needs, and actively explore the optimization of combination therapies for HER2-positive cancer. This includes advancing clinical development for HLX22 to bring hope to more patients around the world.
【Reference】
[1] Bray F, Laversanne M, Sung H, et al. CA Cancer J Clin. 2024: 1-35.
[2] Ajani JA. et al. J Natl Compr Canc Netw 2022;20(2):167-92.
[3] Alsina M. et al. Nat Rev Gastroenterol Hepatol 2023;20(3):155-70.
[4] Gravalos C. et al. Ann Oncol 2008;19(9):1523-9.
[5] NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Gastric Cancer V.1.2024
[6] 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
[7] Jin Li et al., HLX22 plus HLX02 and XELOX for first-line treatment of HER2-positive locally advanced or metastatic gastric/gastroesophageal junction cancer: A randomized, double-blind, multicenter phase 2 study.. JCO 42, 354-354(2024).DOI:10.1200/JCO.2024.42.3_suppl.354
[8] J. Li et al., 422P HLX22 plus HLX02 and XELOX as first-line therapy for HER2-positive advanced gastric/gastroesophageal junction cancer: Updated results from a randomized, double-blind phase II study, Annals of Oncology,Annals of Oncology (2024) 35 (suppl_1): S162-S204. 10.1016/annonc/annonc1482
[9] Li N, Qiu M, Zhang Y, et al. A randomized phase 2 study of HLX22 plus trastuzumab biosimilar HLX02 and XELOX as first-line therapy for HER2-positive advanced gastric cancer. Med. 2024;5(10):1255-1265.e2. doi:10.1016/j.medj.2024.06.004