Teclistamab is a recombinant, humanized IgG4 bispecific monoclonal antibody designed to recognize both B-cell maturation antigen (BCMA) on malignant plasma cells and CD3 on T cells. By simultaneously binding these two targets, teclistamab brings T cells into proximity with BCMA-expressing myeloma cells and promotes T-cell-mediated cytotoxicity.
The pharmaceutical product TECVAYLI (teclistamab-cqyv) was originally approved by the U.S. FDA in October 2022 for adults with relapsed or refractory multiple myeloma after at least four prior lines of therapy, including a proteasome inhibitor, an immunomodulatory agent and an anti-CD38 monoclonal antibody. On March 5, 2026, FDA converted the monotherapy indication to traditional approval and approved teclistamab in combination with daratumumab hyaluronidase-fihj for certain adults with relapsed or refractory multiple myeloma after at least one prior line containing a proteasome inhibitor and an immunomodulatory agent.
Teclistamab is a biological active pharmaceutical ingredient rather than a conventional small-molecule API. FDA's Global Substance Registration System identifies teclistamab as a protein, IgG4 monoclonal antibody, with CAS No. 2119595-80-9 and FDA UNII 54534MX6Z9. FDA's structural record identifies it as a bispecific antibody directed against BCMA and CD3.
The EMA assessment report gives a molecular mass of 146,261 Da for the predominant glycoform. FDA's current GSRS record provides an estimated average molecular weight of approximately 144,000 Da, while the U.S. product label describes the molecular weight as approximately 146 kDa. For pharmaceutical documentation, the EMA predominant-glycoform value and FDA approximate value should be distinguished rather than treated as competing exact molecular weights.
Teclistamab is an engineered IgG4 antibody containing anti-BCMA and anti-CD3 binding arms. The molecule consists of two heavy chains and two light chains connected through disulfide bonds. The Fc region incorporates engineered amino-acid substitutions characteristic of the teclistamab construct.
Unlike conventional chemical APIs, teclistamab is characterized through molecular, structural, physicochemical, purity, potency and biological assays. Its critical quality attributes include molecular identity, aggregation, charge variants, glycosylation, purity, product-related variants and biological activity.
Teclistamab is a BCMA × CD3 T-cell engager. The BCMA-binding arm recognizes BCMA on malignant plasma cells, while the CD3-binding arm recognizes CD3 on T cells. This simultaneous binding forms an immunological bridge between the T cell and the myeloma cell, activating T-cell-mediated killing. Cytotoxic T cells release perforin and granzymes, resulting in lysis of the targeted malignant cells.
Teclistamab is primarily used in oncology, particularly for relapsed or refractory multiple myeloma.
Current FDA-approved applications include:
Quality control of teclistamab requires a biological-drug-substance approach rather than conventional small-molecule testing. Identity, purity, molecular integrity, charge heterogeneity, glycosylation, aggregates and biological potency are among the relevant quality characteristics for a bispecific monoclonal antibody.
The EMA describes teclistamab as a recombinant biological active substance produced through a controlled antibody-engineering and manufacturing process. The active substance is formed from anti-BCMA and anti-CD3 parental antibodies followed by controlled Fab-arm exchange to generate the bispecific molecule.
Accordingly, conventional tests such as loss on drying, residue on ignition, melting point, specific rotation and heavy-metal limits are not appropriate universal release parameters for teclistamab drug substance.
Teclistamab-cqyv is produced using recombinant DNA technology in Chinese hamster ovary (CHO) cells. FDA describes the product as a humanized IgG4-PAA bispecific antibody consisting of anti-BCMA and anti-CD3 heavy- and light-chain components.
The EMA describes production using parental anti-BCMA and anti-CD3 monoclonal antibodies followed by controlled reduction and oxidation to facilitate exchange of Fab arms and formation of the bispecific antibody.
Manufacturing therefore requires controlled cell culture, purification, viral-safety controls, formulation and extensive characterization of the resulting biological drug substance.
The molecular mass and biological structure are supported by EMA and FDA regulatory records. The finished-product concentrations are formulation strengths, not API solubility values.
Commercial teclistamab drug product is supplied as a sterile, preservative-free solution in single-dose vials. FDA identifies presentations containing 30 mg in 3 mL (10 mg/mL) and 153 mg in 1.7 mL (90 mg/mL).
The finished medicinal product requires controlled refrigerated storage according to the applicable approved product information. Drug-substance storage conditions should be established according to validated stability studies and the registered manufacturing specification rather than inferred from the finished-product concentration.
Pharmaceutical-grade Teclistamab API documentation may include:
Teclistamab is a complex bispecific biological API requiring specialized mammalian-cell manufacturing and advanced analytical characterization. A suitable manufacturing program should therefore focus on molecular identity, purity, aggregation, charge variants, glycosylation, biological potency and process-related impurities.
Because teclistamab is a recombinant antibody, its quality specification should be established as a biological drug-substance specification rather than by applying conventional small-molecule API tests such as melting point, residue on ignition or specific rotation.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| pH (1% Solution) | 5.2 |