Shanghai Henlius Biotech Initiates Phase 2/3 Clinical Study for HLX22 and HLX87 in HER2-Positive Breast Cancer

Key Highlights for Investors

• First patient dosed in a pivotal phase 2/3 clinical trial evaluating HLX22 (anti-HER2 monoclonal antibody) with HLX87 (HER2-targeted antibody-drug conjugate) for first-line treatment in HER2-positive recurrent or metastatic breast cancer in Mainland China.
• Innovative drug combination — No similar regimen currently approved for marketing in Mainland China, representing a significant first-mover advantage and potential market opportunity.
• HLX22 has received Orphan Drug Designations from both the US FDA (March 2025) and the European Commission (May 2025) for gastric cancer, underscoring its global development potential.
• HLX87 demonstrates promising efficacy and safety in early trials, with robust preclinical and phase 1 data presented at AACR 2024.
• Regulatory greenlight — Phase 2/3 trials for both first-line and neoadjuvant HER2-positive breast cancer treatments were approved by China’s NMPA in December 2025.
• Potential share price impact: Progress in a large, high-value oncology market and positive early trial data could be material to valuation. However, the company cautions that development and commercialization are not guaranteed.

In-Depth Article

Shanghai Henlius Biotech, Inc. (HKEX: 2696) announced a major milestone with the dosing of the first patient in its phase 2/3 clinical study for the combination of HLX22 and HLX87 in the first-line treatment of HER2-positive recurrent or metastatic breast cancer in Mainland China. This voluntary announcement provides critical updates for shareholders and potential investors, as it marks Henlius’s entry into a highly competitive and lucrative area of oncology with a novel drug regimen.

About the Clinical Study

The trial is an open-label, randomized, multicenter study structured in two stages:

• Phase 2 (Stage 1): Open-label, multicenter, parallel-controlled. Patients are randomized (2:2:1:1) to receive one of four regimens:
  • HLX22 + HLX87
  • Pertuzumab + HLX87
  • Pertuzumab + Trastuzumab deruxtecan
  • Pertuzumab + Trastuzumab + Docetaxel

  Primary endpoints: Objective Response Rate (ORR) and Progression-Free Survival (PFS), both independently reviewed.

• Phase 3 (Stage 2): Eligible subjects randomized (1:1) to receive:
  • HLX22 + HLX87
  • Pertuzumab + Trastuzumab + Docetaxel

  Primary endpoint: PFS assessed by Blinded Independent Central Review (BICR).

Secondary objectives across both stages include evaluating safety, tolerability, pharmacokinetics (PK), immunogenicity, and exploring biomarkers for predicting or resisting treatment.

About HLX22 and HLX87

• HLX22 is a licensed-in anti-HER2 monoclonal antibody developed by Henlius, targeting indications in gastric and breast cancers and other solid tumors. Notably, it has been granted Orphan Drug Designation by the US FDA and EC for gastric cancer, which could facilitate faster pathways to approval and commercialization in major global markets.
• Development progress for HLX22:
  • Phase 3 trial in HER2-positive gastroesophageal and gastric cancers across China, US, EU, Australia, Japan, and other regions.
  • Phase 2/3 trial with HLX87 for HER2-positive breast cancer (current announcement).
  • Phase 2 trial for HER2-low, HR-positive breast cancer.
  • Approved phase 2 trial in locally advanced/metastatic gastric cancer in China.
• HLX87 is a HER2-targeted antibody-drug conjugate (ADC) licensed from GeneQuantum Healthcare. It links a topoisomerase I inhibitor to an anti-HER2 antibody via a stable, cleavable linker, aiming to maximize tumor cell killing and minimize systemic toxicity. Preclinical models showed efficacy comparable to trastuzumab deruxtecan (T-DXd) with a better safety profile. Phase 1 data in HER2-expressing or mutated tumors at AACR 2024 indicated good tolerability (2.0–8.4 mg/kg) and encouraging efficacy in breast, gastric, and lung cancers.

Regulatory and Market Landscape

Notably, the combination of HLX22 and HLX87 has no approved counterpart in Mainland China, presenting Henlius with a potential first-mover advantage in the country’s fast-growing oncology market. Both first-line and neoadjuvant phase 2/3 trial applications for this combination were approved by the National Medical Products Administration (NMPA) in December 2025.

Important Shareholder Information and Potential Price Sensitivity

• This is a significant development in the competitive field of HER2-positive cancer therapy in China and globally. If successful, Henlius could tap a large commercial opportunity and expand internationally.
• Orphan drug designations in the US and EU for HLX22 provide regulatory and commercial incentives, potentially accelerating future approvals and exclusivity periods.
• Early clinical and preclinical results for HLX87 are promising, indicating strong efficacy and safety — key factors for eventual regulatory approval and market adoption.
• As of this announcement, no similar combination is approved in China, enhancing the news’ potential impact on share price.
• However, the company cautions shareholders and potential investors that successful development and commercialization are not guaranteed.

Corporate Governance

The announcement is signed by Chairman Wenjie Zhang, with the board comprising a mix of executive, non-executive, and independent directors, underscoring robust corporate oversight.

Conclusion

The initiation of this pivotal clinical trial positions Shanghai Henlius Biotech at the forefront of innovative HER2-positive cancer treatment in China. This, along with its global regulatory progress and unique product portfolio, could be material to the company’s valuation and future growth prospects. Investors should closely monitor further trial updates and regulatory milestones, as these could be key drivers of share price.

Disclaimer

This article is for informational purposes only and does not constitute investment advice. The successful development and commercialization of HLX22 and HLX87 are subject to substantial risks and uncertainties. Investors are advised to exercise caution and perform their own due diligence when making investment decisions regarding Shanghai Henlius Biotech, Inc.

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