Shanghai, China, May 23, 2026 — Shanghai Henlius Biotech, Inc. (2696.HK) announced that the first patient has been dosed in a Phase 1 clinical study (HLX316-FIH101) of HLX316, a potential first‑in‑class (FIC) B7‑H3–targeted sialidase fusion protein, in China. This progress marks the official entry of HLX316 into the Phase 1 clinical study stage to evaluate its safety, tolerability, and preliminary efficacy in patients with advanced/metastatic solid tumors.
Scientific Rationale: Targeting Dual Immune Evasion Pathways
HLX316 is an engineered human sialidase fusion protein targeting B7‑H3 (CD276).. The molecule is engineered to address two major immune evasion mechanisms commonly observed in solid tumors: B7-H3 overexpression and tumor hypersialylation.
B7-H3 is an immune checkpoint protein that is overexpressed in many solid tumors—including lung, breast, colorectal, pancreatic, prostate, and ovarian cancers—and is associated with tumor progression and poor prognosis, while exhibiting limited expression in normal tissues. High levels of sialylation on tumor cells engage inhibitory Siglec receptors on leukocytes, suppressing both innate and adaptive immune effector functions.
HLX316 enzymatically removes terminal sialic acids and preferentially enriches its activity in B7-H3–positive tumor cells, thereby relieving glyco‑immune checkpoint–mediated immunosuppression and restoring innate and adaptive antitumor immune functions within the tumor microenvironment.
By selectively targeting sialidase activity in B7-H3–expressing tumor cells and their microenvironment, HLX316 has the potential to simultaneously alleviate protein‑ and glycan‑mediated immune suppression, expand the applicability of immunotherapy in solid tumors, and overcome the limitations of existing treatment modalities. Preclinical studies have demonstrated that HLX316 induces potent B7-H3–directed desialylation of tumor cells with a favorable tolerability profile.
Systematic Innovation Driving a Diversified and Differentiated Pipeline
HLX316 is one of the innovative programs arising from Henlius’ strategic collaboration with Palleon Pharmaceuticals. Palleon was co-founded on the glycobiology research of Dr. Carolyn Bertozzi (2022 Nobel laureate in Chemistry) and is the first company to translate this science into human therapeutics targeting cell surface sialoglycans. By leveraging the complementary strengths of both parties, HLX316 (Palleon code: E-688) is advancing toward global clinical development. The IND approval of HLX316 further reflects the accelerated momentum of Henlius’ innovation engine. Leveraging its PD‑(L)1–centered immune checkpoint inhibitor platform, immune cell engager platforms (including multispecific T‑cell engager technologies), Hanjugator™ ADC platform, fusion protein technologies, and the AI‑powered one‑stop early discovery platform HAI Club, Henlius is systematically building a multi‑modal innovation ecosystem spanning multi-specific antibodies, ADCs, fusion proteins and small‑molecule inhibitors.
Within this framework, several differentiated assets are advancing through early‑stage development. HLX701 (novel SIRPα-Fc fusion protein) has initiated a phase 2 clinical study in China. In addition, HLX37 (anti-PD-(L)1/VEGF bispecific antibody), HLX97, a potential best-in-class KAT6A/B inhibitor, and HLX3901, a DLL3xDLL3xCD3xCD28 tetra‑specific T‑cell engager (TCE) developed from Henlius’ proprietary TCE platform, have completed their first patient dosage along with HLX316.
In parallel, several other programs are progressing toward clinical development, including HLX3902 (STEAP1 × CD3 × CD28 trispecific T‑cell engager), HLX48 (cMET × EGFR bsADC), HLX49 (HER2 × HER2 bsADC), and HLX105 (PD1×IL2 fusion protein). Collectively, these programs form a well‑tiered and technology‑diverse early‑stage pipeline.
Henlius is building a sustainable innovation pipeline with long‑term value creation capabilities. As core products advance into global pivotal clinical stages and progressively move toward registration and commercialization, the company has transitioned from “breakthrough innovation” to a new phase of “systematic innovation.” Looking ahead, Henlius will continue to deepen its Globalization 2.0 strategy, while maintaining robust cash flow to support R&D investment, accelerating the global development and translation of differentiated innovative assets, and bringing more internationally competitive products to mature markets in Europe and the United States, steadily advancing toward its vision of becoming a global biopharmaceutical company by 2030.
About HLX316 -FIH101
This is an open-label, first-in-human phase 1 clinical study to evaluate the safety, tolerability, pharmacokinetic profiles, and preliminary efficacy of HLX316 in patients with advanced/metastatic solid tumours. The study consists of two stages: phase 1a dose escalation and backfill stage, and phase 1b dose expansion stage. Phase 1a includes five dose levels ranging from 1.0 mg/kg to 30.0 mg/kg, with once-weekly administration. The 1.0 mg/kg cohort adopts an accelerated titration design, while the remaining four dose cohorts follow a “3+3” dose escalation design. Dose backfill may be conducted at selected dose levels following safety evaluation. The dose level(s) for phase 1b expansion will be determined based on the safety and preliminary efficacy data from phase 1a, with a dosing regimen consistent with the corresponding cohort(s) in phase 1a. The primary objectives of this study are to evaluate the safety and tolerability of HLX316 in patients with advanced/metastatic solid tumours, to determine its maximum tolerated dose (“MTD”) and recommended phase 2 dose (“RP2D”), and to preliminarily evaluate its anti-tumour efficacy. The primary endpoints include the incidence of dose-limiting toxicities (DLTs), the MTD and RP2D of HLX316, and the objective response rate (ORR) assessed by the investigator.
