Odronextamab is a fully human, IgG4-based bispecific monoclonal antibody designed to simultaneously recognize CD20 on B cells and CD3 on T cells. By binding these two targets, odronextamab brings T cells into close proximity with CD20-expressing B cells and promotes T-cell-mediated destruction of the target cells.
Odronextamab is also known by the development codes REGN1979 and REGN-1979. Its CAS Registry Number is 1801338-64-6 and its FDA Unique Ingredient Identifier (UNII) is 8R5CM46UIO.
PubChem identifies odronextamab as a hinge-stabilized, fully human IgG4-based CD20×CD3 bispecific antibody.
Odronextamab contains two different antigen-binding specificities within a single bispecific antibody molecule. One binding arm recognizes CD20, a B-cell surface antigen, while the other recognizes CD3, a T-cell antigen.
The antibody is based on an IgG4 framework with Fc modifications intended to minimize Fc-mediated effector activity. IUPHAR describes odronextamab as a fully human CD3ε/CD20 bispecific IgG4-based antibody with minimized Fc-mediated effector function.
Odronextamab simultaneously binds CD20-expressing B cells and CD3-positive T cells. This creates an immune synapse between the T cell and target B cell, resulting in T-cell activation and cytotoxic activity against the CD20-expressing cell.
Odronextamab is the active substance in Ordspono. The European Medicines Agency states that Ordspono is indicated as monotherapy for adults with relapsed or refractory follicular lymphoma after two or more systemic therapies and relapsed or refractory diffuse large B-cell lymphoma (DLBCL) after two or more systemic therapies.
As a bispecific monoclonal antibody, odronextamab requires biologic-specific quality assessment rather than conventional small-molecule API testing.
Relevant quality attributes include:
The antibody's biological activity is particularly important because its therapeutic function depends on simultaneous recognition of CD20 and CD3.
| Parameter | Specification |
|---|---|
| Appearance | White crystalline powder or crystals |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Individual Impurity | NMT 0.5% |
| Water Content | NMT 0.5% |