By Fineline Cube Shanghai Henlius Biotech, Inc. (HKG: 2696) announced that HLX3901, a first-in-class tetra-specific antibody targeting DLL3 dual epitopes, CD3, and CD28, has received NMPA IND approval for a Phase I clinical trial in advanced/metastatic solid tumors. The independently developed candidate represents a next-generation T-cell engager designed to overcome immune suppression and enhance therapeutic efficacy through simultaneous activation of primary and co-stimulatory T-cell signals, positioning Henlius at the forefront of multi-specific antibody innovation.
Regulatory Milestone
| Item | Detail |
|---|---|
| Agency | National Medical Products Administration (NMPA) |
| Approval Type | Investigational New Drug (IND) – Phase I |
| Product | HLX3901 injection |
| Drug Class | Tetra-specific antibody (DLL3×DLL3×CD3×CD28) |
| Indication | Advanced/metastatic solid tumors |
| Developer | Shanghai Henlius Biotech, Inc. (HKG: 2696) |
| Global Status | No approved tetra-specific antibody targeting this combination worldwide |
| Approval Date | 10 Mar 2026 |
Drug Profile & Mechanism
| Attribute | HLX3901 Specification |
|---|---|
| Format | Tetra-specific antibody (4 distinct binding domains) |
| Targets | • DLL3 dual epitopes (tumor antigen – delta-like ligand 3) • CD3 (T-cell receptor – primary activation signal) • CD28 (T-cell co-stimulatory receptor) |
| Mechanism Class | T-cell engager with dual-signal activation |
| Action | • Enhances targeted T-cell lysis of DLL3-positive tumor cells • Activates CD3 (Signal 1) + CD28 (Signal 2) simultaneously • Promotes T-cell activation, proliferation, and in vivo survival |
Scientific Innovation:
- Dual DLL3 Epitope Binding: Enhanced tumor specificity and avidity vs. single-epitope targeting
- Signal 1 + Signal 2 Co-activation: Mimics physiological T-cell activation; reduces exhaustion vs. CD3-only engagers
- Immune Suppression Overcome: Co-stimulation counteracts tumor microenvironment inhibitory signals
Preclinical Evidence & Differentiation
| Parameter | HLX3901 Performance |
|---|---|
| Anti-Tumor Efficacy | Good activity demonstrated in disease models |
| Safety Profile | Favorable preclinical tolerability |
| Therapeutic Window | Improved vs. conventional T-cell engagers (reduced on-target/off-tumor toxicity) |
| T-Cell Persistence | Enhanced activation, proliferation, and survival prolong anti-tumor immune response |
Competitive Positioning:
| Competitor Approach | Mechanism | HLX3901 Advantage |
|---|---|---|
| Bispecific T-cell engagers (BiTEs) | CD3 + tumor antigen (e.g., blinatumomab) | Adds CD28 co-stimulation + dual DLL3 targeting for enhanced efficacy and persistence |
| CAR-T therapies | Engineered T-cells | Off-the-shelf convenience; no lymphodepletion required; lower manufacturing complexity |
| Other multi-specifics | Tri-specific formats | Tetra-specific adds dual epitope avidity + co-stimulation; first-in-class globally |
Strategic Context & Market Opportunity
| Factor | Implication |
|---|---|
| DLL3 Expression | High in small cell lung cancer (SCLC), neuroendocrine tumors, subset of solid tumors; validated by rovalpituzumab tesirine (failed ADC) and DLL3-CAR-T trials |
| T-Cell Engager Market | Global market projected $15+ billion by 2030; solid tumor applications expanding beyond hematologic malignancies |
| Henlius Pipeline | HLX3901 anchors next-generation immuno-oncology platform; complements approved PD-1 (serplulimab) and biosimilar portfolio |
| Global Potential | First-in-class status supports U.S./EU IND filing; Fast Track designation potential for SCLC indication |
| Manufacturing | Henlius’ integrated biologics facility supports clinical and commercial tetra-specific production |
Development Outlook
| Phase | Timeline | Objectives |
|---|---|---|
| Phase I | 2026-2027 | Safety, tolerability, MTD; DLL3-positive tumor enrichment (SCLC, neuroendocrine) |
| Phase II | 2027-2029 | Efficacy signals; combination with PD-1; biomarker development |
| Regulatory Strategy | 2029-2030 | Breakthrough Therapy designation pursuit; NDA preparation |
Forward‑Looking Statements
This brief contains forward‑looking statements regarding clinical development timelines, first-in-class positioning, and competitive differentiation for HLX3901. Actual results may differ due to novelty of tetra-specific format, manufacturing complexity, and competitive dynamics in the T-cell engager market.-Fineline Info & Tech