First Patient Dosed in Phase 2 Clinical Trial of HLX22 Combo Therapy in Patients with HER2-positive Gastric Cancer
Shanghai, China, September 30th, 2021-Shanghai Henlius Biotech, Inc. (2696.HK) announced that the first patient has been dosed in Chinese mainland in a Phase 2 clinical trial to compare the Company’s HLX22，an anti-human epidermal growth factor receptor-2 (HER2) humanized monoclonal antibody injection) in combination with 汉曲优® (trastuzumab injection, EU trade name: Zercepac®) and chemotherapy as first-line therapy for HER2-positive locally advanced or metastatic gastric cancer patients. As of now, no similar dual blockade therapy for the treatment of HER2-positive gastric cancer has received approval for commercialization from the National Medical Products Administration (NMPA).
Gastrointestinal tumours are high incidences malignant tumours in China, among which the newly diagnosed patients with gastric cancer in 2020 was about 478,500, only less than patients with colorectal cancer[1]. The prognosis of gastric cancer is generally not optimistic, especially for locally advanced and metastatic gastric cancer[2]. Although surgical resection provides effective debulking treatment for gastric cancer patients, postoperative recurrence and metastasis remain the important causes of death. As of now, trastuzumab combined with doublet chemotherapy has become the first-line standard treatment for patients with metastatic gastric cancer[3]. However, there is still room to improve the median progression-free survival based on the ToGA trial[4]. More effective therapies are urgently needed.
This two-part study aims to compare the efficacy and safety of HLX22 versus placebo in combination with trastuzumab injection and XELOX, as first-line therapy for HER2-positive locally advanced or metastatic gastric cancer patients. Part one is a safety run-in stage, in which patients will receive 15mg/kg HLX22 in combination with trastuzumab injection and XELOX. Part two is a randomised, double-blind, multi-centre, phase 2 study. Eligible patients will be randomised 1:1:1 to receive HLX22 (group A: HLX22, 25mg/kg; group B: HLX22, 15mg/kg) in combination with trastuzumab injection and XELOX, or placebo in combination with trastuzumab injection and XELOX (group C). The primary objective of this study is to compare the clinical efficacy in HLX22 and placebo group. 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 in HLX22 and placebo groups.
HLX22 is an innovative anti-HER2 monoclonal antibody introduced from AbClon, Inc. and further researched and developed by Henlius, indicated for the treatment of gastric cancer and breast cancer. In February 2019, the clinical trial application for HLX22 was approved by the NMPA. In July 2019, the first patient was dosed in Chinese mainland in a phase 1 clinical trial of HLX22 for advanced solid tumours that have failed standard therapy. HLX22 can also bind to HER2 subdomain at a different binding site from trastuzumab, which allows of simultaneous binding of HLX22 and trastuzumab to HER2. The research showed that the combination therapy of HLX22 and trastuzumab would inhibit 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. In the xenograft mouse tumour model, the efficacy of the combo therapy is superior to that of trastuzumab. The phase 1 clinical trial of HLX22 demonstrates that HLX22 is well tolerated and has good safety profiles.
Up to now, Henlius has a well-established product pipeline in the area of anti-HER2 treatment. With the accumulated results and experience from extensive anti-HER2 research, the Company has also built a solid foundation for discovering and developing anti-HER2 bispecific/multi-target antibodies. The company’s independently developed and manufactured trastuzumab biosimilar汉曲优® was approved in the EU and China, providing a new standard treatment option for Chinese and European HER2 positive breast and gastric cancer patients. In the future, HLX22 can also be combined with 汉曲优® or HLX11 in the treatment of HER2 positive breast and gastric cancers, which will strengthen Henlius’ strategy of “Combo+Global”. The company will continue innovating and strive for breakthroughs to bring more affordable and quality biologics to patients around the globe.
Reference Notes:
[1] Cao W, Chen HD, Yu YW, Li N, Chen WQ. Changing profiles of cancer burden worldwide and in China: a secondary analysis of the global cancer statistics 2020. Chin Med J (Engl). 2021;134(7):783-791.
[2] Li R, Leng AM, Liu T, et al. Weekday of Surgery Affects Postoperative Complications and Long-Term Survival of Chinese Gastric Cancer Patients after Curative Gastrectomy. Biomed Res Int. 2017;2017:5090534.
[3] 中国临床肿瘤学会（CSCO）胃癌诊疗指南，2020 中国临床肿瘤学会指南工作委员会。
[4] Bang YJ, Van Cutsem E, Feyereislova A, et al. Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer (ToGA): a phase 3, open-label, randomised controlled trial . Lancet. 2010;376(9742):687-697.
