Shanghai Henlius Biotech Announces Major Clinical Trial Milestone for HLX43 in Japan

Key Highlights

• International multicenter Phase 2/3 clinical trial of HLX43 (an anti-PD-L1 antibody-drug conjugate) in advanced squamous non-small cell lung cancer (NSCLC) permitted to commence in Japan
• Trial will evaluate HLX43 both as a monotherapy and in combination with pimurutamab HLX07 (recombinant anti-EGFR humanized monoclonal antibody injection) versus Docetaxel
• HLX43 has shown positive safety and efficacy signals in prior Phase 1 and 2 trials in multiple solid tumor types, including NSCLC, cervical cancer, and esophageal squamous cell carcinoma
• No similar combination therapy has been approved for marketing globally, underscoring the innovative nature and potential market opportunity

Detailed Overview

Shanghai Henlius Biotech, Inc. has voluntarily announced a significant regulatory milestone in its global clinical development program. The Japanese Pharmaceuticals and Medical Devices Agency (PMDA) has granted implied approval for the company’s international multicenter Phase 2/3 clinical trial of HLX43, an anti-PD-L1 antibody-drug conjugate, as both a monotherapy and in combination with pimurutamab HLX07, for advanced squamous NSCLC. Upon fulfillment of certain conditions, Henlius will soon commence this pivotal study in Japan. This development represents a critical advancement in Henlius’ effort to expand its innovative oncology portfolio on the global stage.

About HLX43

HLX43 is an antibody-drug conjugate (ADC) targeting PD-L1, developed by Henlius using a novel DNA topoisomerase I inhibitor payload with a proprietary peptide linker. The ADC is engineered for the treatment of advanced or metastatic solid tumors. HLX43 is currently at various stages of clinical development worldwide:

• Phase 1 clinical trial in Chinese Mainland for advanced/metastatic solid tumors
• Phase 1 clinical trial in Japan for thymic carcinoma (TC); permitted to commence Phase 1 trials in the United States
• Ongoing Phase 2 international multicenter trial in advanced NSCLC (Chinese Mainland, US, Australia, Japan)
• Phase 2 clinical trials for metastatic colorectal cancer (mCRC), cervical cancer (CC), and esophageal squamous cell carcinoma (ESCC) in Chinese Mainland
• Combination studies with HANSIZHUANG and HLX07 in various solid tumor settings

Clinical Data and Efficacy Signals

Data from the Phase 1 clinical trial of HLX43, presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting and the 2025 World Conference on Lung Cancer (WCLC), demonstrated good safety and encouraging efficacy across multiple solid tumors, including NSCLC. Notably, in heavily pre-treated NSCLC patients (median lines of prior therapy ≥3), HLX43 monotherapy achieved an investigator-assessed objective response rate (ORR) of 37.0% and a disease control rate (DCR) of 87.0%.

In cervical cancer, Phase 2 data presented at the 2025 ESMO Asia Congress showed an overall ORR of 41.4%, with responses reaching 70% in the 3.0mg/kg dose group among patients who had failed or were intolerant to standard first-line therapy. For esophageal squamous cell carcinoma, data from the 2026 ASCO Gastrointestinal Cancers Symposium demonstrated an ORR of 30.3% overall, with an impressive 61.5% in the 3.0mg/kg cohort.

Importantly, HLX43 appears to act as a biomarker-independent ADC with immuno-oncology activity, potentially enabling broad patient coverage and differentiation from existing therapies.

About HLX07

HLX07 is an innovative, independently developed anti-EGFR humanized monoclonal antibody. It is intended for use against advanced solid tumors and has demonstrated a favorable safety profile in a Phase 1b/2 study in combination with chemotherapy. Multiple Phase 2 trials are underway in the Chinese Mainland, including monotherapy for advanced cutaneous squamous cell carcinoma and combinations with HANSIZHUANG in squamous NSCLC and other solid tumors.

Market Implications and Shareholder Considerations

• First-in-class Opportunity: As of this announcement, no similar combination therapy has been approved globally, positioning Henlius at the forefront of innovation in the anti-PD-L1 ADC and EGFR antibody space.
• Strong Efficacy Signals: HLX43 has delivered promising response rates in highly refractory patient populations, which could translate to significant clinical and commercial potential if replicated in larger trials.
• Regulatory Milestone in Japan: The PMDA’s implied approval to commence a pivotal Phase 2/3 trial in Japan is a major regulatory achievement, expanding the company’s global clinical footprint and potentially accelerating path to market for HLX43.
• Potential Share Price Catalyst: The initiation of this trial, combined with positive early data and the absence of approved competitors for this combination, may be viewed favorably by investors as a forward-looking catalyst for share value appreciation.
• Risks: The company cautions that successful development and commercialization of HLX43 and HLX07 are not guaranteed. Shareholders should remain aware of the inherent risks in clinical development.

Board and Leadership

The announcement was made on behalf of the Board of Shanghai Henlius Biotech, Inc. by Chairman Wenjie Zhang on 4 May 2026. The Board is composed of a mix of executive, non-executive, and independent non-executive directors, reflecting strong corporate governance.

Conclusion

The commencement approval for the major international multicenter Phase 2/3 trial of HLX43 in Japan represents a significant milestone for Shanghai Henlius Biotech. This development could have a material impact on the company’s future prospects, offering both clinical and commercial upside if successful. Investors should monitor further updates on trial initiation and clinical progress as potential share price catalysts.

Disclaimer: This article is for informational purposes only and does not constitute investment advice or a recommendation to buy or sell any securities. Clinical trial outcomes are inherently uncertain, and there is no guarantee of success or commercialization of the products mentioned. Investors should conduct their own due diligence and consult with professional financial advisors before making investment decisions.

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