Innovative Bispecific Nanobody Targeting CD3 Complex and TPBG for Advanced Cancer Therapy
VHH-P839 is a next-generation humanized nanobody designed to target both the CD3 Complex (T Cell Receptor Complex) and trophoblast glycoprotein (TPBG), two critical molecules implicated in cancer biology. Currently in the Biological Testing phase, VHH-P839 offers promising potential as a targeted therapeutic for various malignancies. By engaging the CD3 Complex to harness T cell activity while simultaneously binding TPBG commonly overexpressed in tumors, this bispecific construct augments immune-mediated cytotoxicity against cancer cells. Its humanized single-domain antibody format supports favorable developability and safety profiles, positioning VHH-P839 as a highly differentiated approach for cancer intervention.
| Candidate | VHH-P839 |
| Target | CD3 Complex (T Cell Receptor Complex) trophoblast glycoprotein (TPBG) |
| Modality | humanized bispecific VHH |
| Indication | Cancer |
Licensing Opportunity
VHH-P839 is currently available for out-licensing or collaborative partnership opportunities. Innovative biotech and pharmaceutical companies are invited to join in advancing this unique bispecific nanobody toward clinical and commercial success.
Contact UsDevelopment Phase
| Program | Research | Preclinical | Phase 1 |
|---|---|---|---|
| VHH-P839 |
Modality
VHH-P839 is a tetravalent bispecific construct composed of four single-domain antibody units: two high-affinity sdAbs specific for TPBG and a VH/VL sdAb pair designed for CD3-restricted engagement. This modular nanobody architecture allows for compact size, robust tissue penetration, and enhanced tumor targeting capability — critical factors for solid tumor treatment. The effector-disabled Fc domain further enhances safety by minimizing off-target immune activation. With the superior stability and solubility intrinsic to nanobodies, VHH-P839 is well-suited for cancer therapy where deep tissue access and controlled immune activation confer a therapeutic edge.
Target
CD3 Complex and TPBG represent pivotal targets in cancer immunotherapy. The CD3 Complex, a multimeric cell surface receptor complex expressed exclusively on T cells, orchestrates antigen recognition and downstream T cell signaling, making it essential for immune response modulation. TPBG, a surface glycoprotein, is frequently overexpressed on the surface of various cancer cells but is limited in healthy tissues. TPBG’s presence contributes to tumor invasiveness and poor prognosis. Targeting the CD3 Complex unleashes T cell-mediated cytotoxicity, while TPBG-directed targeting ensures specificity towards tumor cells. VHH-P839's strategic dual targeting of CD3 Complex and TPBG maximizes anti-tumor activity while minimizing off-tumor effects, offering considerable therapeutic and commercial value.
Mechanism of Action
VHH-P839 simultaneously binds CD3 Complex on T cells and TPBG on tumor cells, bringing these two populations into close proximity. This dual specificity redirects T cell cytotoxicity specifically toward TPBG-expressing cancer cells. Interaction with CD3 Complex activates T cell receptor signaling, promoting T cell activation, proliferation, and targeted killing of malignant cells. The unique nanobody framework enhances tumor infiltration and reduces non-specific immune activation due to the effector-disabled Fc. In addition, the underlying platform is amenable to further molecule engineering such as the development of antibody-drug conjugates (ADC) or additional bispecific/tri-specific formats, enhancing VHH-P839’s adaptability for diverse oncology applications.
Cancer
Cancer encompasses a broad spectrum of malignant diseases characterized by uncontrolled cell proliferation and the ability to invade or metastasize to distant tissues. As a leading global cause of death, cancer poses a significant public health burden with rising incidence rates. Standard treatment modalities include surgery, chemotherapy, radiation, immunotherapy, and targeted therapies. While these interventions have extended survival for many patients, limitations such as off-tumor toxicity, drug resistance, and insufficient responses in certain patient populations underscore substantial unmet medical needs. Immunotherapeutic strategies, especially those leveraging T cell engagement, have revolutionized the landscape but still require improvements in specificity, efficacy, and safety. VHH-P839, by selectively targeting CD3 Complex on T cells and TPBG on cancer cells, offers a differentiated mechanism that could overcome existing therapeutic barriers, providing new hope for patients with refractory or relapsed malignancies.