First Subject Dosed In Phase 3 Clinical Trial Of Pertuzumab Biosimilar HLX11

Shanghai Henlius Biotech, Inc. announced that the first subject has been dosed in phase 3 clinical trial of the company’s pertuzumab biosimilar HLX11, a recombinant anti-human epidermal growth factor receptor 2 (HER2) subdomain II humanized monoclonal antibody injection, for the neoadjuvant therapy in patients with HER2-positive, HR-negative early or locally advanced breast cancer. In November 2021, the phase 1 clinical trial of HLX11 met its primary endpoint, demonstrating that HLX11 had similar pharmacokinetic, Immunogenicity and safety profiles to the reference drugs from different sources.

HLX11 is a pertuzumab biosimilar developed by Henlius independently in line with relevant regulations and guidelines on biosimilars in China and the European Union (EU), which can be potentially used in combination with trastuzumab and chemotherapy as neoadjuvant or adjuvant treatment for HER2 positive early breast cancer and in combination with trastuzumab and docetaxel in patients with HER2 positive metastatic or unresectable locally recurrent breast cancer patients. HLX11 can specifically bind with the subdomain II of HER2 extracellular domain and inhibit the heterodimerisation of HER2 and other HER family receptors, i.e., EGFR, HER3, and HER4. This will inhibit signal transduction of relevant pathways and lead to the stop of growth and apoptosis of tumour cells. In the meantime, HLX11 can also enhance the tumour-killing activity of immune cells via antibody-dependent cell cytotoxicity.

With the accumulated results and experience from extensive anti-HER2 research, Henlius has a well-established product pipeline in anti-HER2 treatment and built a solid foundation for discovering and developing anti-HER2 bispecific/multi-target antibodies and antibody-drug conjugates (ADC). Up to now, the company’s independently developed and manufactured trastuzumab biosimilar HANQUYOU (Zercepac in the EU) was approved in the EU and China, providing a new standard treatment option for Chinese and European HER2 positive breast and gastric cancer patients. Besides, HLX22, an anti-human epidermal growth factor receptor-2 (HER2) humanized monoclonal antibody injection in phase 2 clinical trial, also has the potential to further improve treatment outcomes for HER2 positive breast cancer and gastric cancer patients. In the future, HLX11 can also be combined with HANQUYOU or HLX22, which will strengthen Henlius’ strategy of Combo. The company will continue innovating and strive for breakthroughs to bring more affordable and quality biologics to patients around the globe.

About HLX11-BC301
This multicentre, randomised, double-blind, parallel-controlled phase 3 study aims to compare the efficacy and safety of HLX11 with reference pertuzumab as neoadjuvant therapy in patients with HER2-positive, HR-negative early or locally advanced breast cancer. Eligible patients will be randomised 1:1 to receive either HLX11 or reference pertuzumab in combination with trastuzumab and docetaxel every three weeks for four cycles. The primary endpoint of this study is the total pathological complete response (tpCR) rate assessed by Independent Review Committee (IRC). The secondary endpoints include tpCR assessed by investigators, breast pathologic complete response (bpCR) rate, objective response rate (ORR), event-free survival (EFS), disease-free survival (DFS), safety, pharmacokinetics, and immunogenicity.