Shanghai, China – March 3, 2026 – Henlius Biotech, Inc. (HKEX: 2696), a global biopharmaceutical leader in oncology innovation, today announced the successful dosing of the first patient in its Phase 2/3 clinical trial evaluating HLX22, a next-generation bispecific antibody licensed from Alligator Bioscience AB (publ) (STO: ATORX). This pivotal trial targets HER2-positive breast cancer, a subtype affecting approximately 15-20% of the 2.3 million annual global cases, where current therapies like trastuzumab achieve response rates of 50-60% but face resistance in up to 30% of patients within one year.
HLX22 is a fully human CD40 agonistic and tumor-directed bispecific antibody designed to selectively activate immune responses within the tumor microenvironment. By targeting CD40 on antigen-presenting cells while binding tumor-associated antigens, HLX22 triggers potent anti-tumor immunity with minimized systemic toxicity—preclinical data showed up to 90% tumor regression in HER2+ xenograft models versus 40% for CD40 monotherapy. The Phase 2/3 trial (NCT identifier pending) is a randomized, multicenter study enrolling ~500 patients across Asia, Europe, and North America. Phase 2 will assess safety, optimal dosing (starting at 1-10 mg/kg IV Q3W), and preliminary efficacy via objective response rate (ORR) per RECIST 1.1; Phase 3 will compare HLX22 plus standard-of-care (SOC) trastuzumab + pertuzumab against SOC alone, with dual primary endpoints of progression-free survival (PFS) and overall survival (OS).
“This first-in-human dosing marks a critical inflection point for HLX22, bridging early Phase 1 data (showing favorable safety with only 10% Grade 3+ AEs and durable responses in 40% of heavily pretreated patients) to registrational intent,” said Dr. Weiming Mao, Chief Scientific Officer at Henlius. “In an era where immuno-oncology combinations extend PFS by 4-6 months in HER2+ metastatic settings (e.g., DESTINY-Breast03 data), HLX22’s tumor-selective agonism addresses key gaps in resistance and immune evasion.”
Strategically, HLX22 exemplifies Henlius’ multi-oncology platform potential. Beyond breast cancer, ongoing investigator-initiated trials explore its synergy in non-small cell lung cancer (NSCLC, 20-25% HER2-mutated), gastric cancer (10-15% HER2+), and colorectal cancer via combinations with PD-1 inhibitors. Insights from recent meta-analyses (e.g., Lancet Oncology 2025) highlight CD40 agonists’ 25% PFS uplift in solid tumors when tumor-targeted, positioning HLX22 to capture a share of the $15B+ HER2 franchise expanding at 12% CAGR through 2030.
Henlius, with its integrated CMC and global regulatory expertise, plans topline Phase 2 data in H2 2027 and Phase 3 readout by 2029, accelerating toward NDA filings. This builds on Henlius’ track record, including approvals for HLX02 (trastuzumab biosimilar) in 20+ markets and ongoing successes in ADCs and bispecifics.
About Henlius
Henlius Biotech is a fully integrated biopharma driving oncology breakthroughs through innovative biologics. With 30+ molecules in clinic and partnerships spanning AstraZeneca and Innovent, Henlius serves 5,000+ patients monthly across 12 approved products.
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