Oprelvekin API is a recombinant human interleukin-11 (IL-11) and a biotechnology-derived pharmaceutical active ingredient. Unlike conventional synthetic small-molecule APIs, Oprelvekin is a recombinant protein produced using recombinant DNA technology. FDA records identify Oprelvekin under UNII HM5641GA6F, while the established CAS Registry Number is 145941-26-0.
Oprelvekin is a non-glycosylated recombinant protein consisting of 177 amino acids and having a molecular mass of approximately 19,000 daltons. It differs from native human IL-11 by lacking the amino-terminal proline residue, resulting in a 177-amino-acid recombinant protein compared with the 178-amino-acid native protein. FDA documentation states that this structural difference did not result in measurable differences in biological activity in the referenced in-vitro and in-vivo evaluations.
Oprelvekin is also known by names including Recombinant Human Interleukin-11, Recombinant Interleukin-11, rhIL-11, Interleukin-11 (2-178), and Neumega. Its WHO ATC classification is L03AC02, placing it within the interleukin group of immunostimulants.
Oprelvekin belongs to the cytokine family and is classified pharmacologically as a megakaryocyte growth factor. Its biological activity is associated with stimulation of hematopoietic stem cells and megakaryocyte progenitor cells, supporting megakaryocyte maturation and thrombopoiesis. This biological mechanism is responsible for its historical pharmaceutical application in chemotherapy-associated thrombocytopenia.
Because Oprelvekin is a recombinant protein, its characterization differs substantially from that of a conventional organic API. Protein identity, molecular mass, purity, biological potency, aggregation, charge variants and process-related impurities are more meaningful quality attributes than conventional parameters such as melting point or residue on ignition.
Oprelvekin is produced using recombinant DNA technology in Escherichia coli. The resulting recombinant protein is non-glycosylated and has an approximate molecular mass of 19 kDa.
Manufacturing of a recombinant Oprelvekin API therefore requires appropriate control of the expression system, cell banks, fermentation or cultivation process, harvest, purification and formulation-related operations. Downstream purification is particularly important for controlling host-cell proteins, residual host-cell DNA, process-related impurities and protein aggregates.
A comprehensive quality-control strategy for recombinant Oprelvekin can include identity testing, molecular-weight confirmation, chromatographic purity, electrophoretic characterization, peptide mapping, protein concentration, biological activity/potency, aggregate assessment, host-cell protein, residual DNA, endotoxin and microbiological controls.
Oprelvekin has historically been used as a thrombopoietic growth factor. The FDA-approved product Neumega was indicated for the prevention of severe thrombocytopenia and reduction of platelet-transfusion requirements following myelosuppressive chemotherapy in specified adult patients with nonmyeloid malignancies who were considered at high risk of severe thrombocytopenia.
The FDA historical labeling describes Neumega as containing 5 mg of Oprelvekin per single-use vial, supplied as a sterile lyophilized powder. The referenced formulation contained glycine and phosphate-buffer components. When reconstituted with 1 mL of Sterile Water for Injection, the historical product produced a concentration of 5 mg/mL and a pH of 7.0.
These values describe the historical finished pharmaceutical product and should not be presented as universal bulk-API specifications.
Quality control for Oprelvekin API requires a biological-product approach. The API should be evaluated using validated analytical methods appropriate for recombinant proteins.
Important characterization areas include protein identity, molecular mass, purity, biological activity and structural integrity. Additional controls may address protein aggregation, host-cell-derived impurities, residual DNA, endotoxin and microbial quality.
For this reason, conventional CMS fields such as melting point, optical rotation, residue on ignition and loss on drying are generally not appropriate universal release criteria for Oprelvekin. Where no authoritative universal numerical limit is established, the value should be recorded as N/A or product-specific, rather than assigning an unsupported numerical specification.
For an Oprelvekin API specification sheet, the most relevant numerical characteristics are the approximately 19,000 Da molecular mass and 177-amino-acid protein length. The FDA historical label also reports a specific activity of approximately 8 × 10⁶ Units/mg for the finished product material.
The specific activity value should be treated as a historical product characterization value, not automatically as a universal current release specification for every Oprelvekin API manufacturer.
Similarly, the historical product's pH of 7.0 applies to the reconstituted Neumega formulation and should not be transferred directly to a bulk API specification.
The historical U.S. product Neumega was approved by the FDA in 1997. FDA's Purple Book record identifies Oprelvekin as the proper name and records the product as a single-dose injection administered subcutaneously. The record currently indicates voluntarily revoked licensure.
This regulatory history is important when preparing commercial or technical content. Oprelvekin remains a recognized recombinant pharmaceutical protein and API identity, but historical U.S. product approval status should not be described as a currently marketed U.S. product.
An Oprelvekin API manufacturer in India requires appropriate biotechnology capabilities for recombinant protein production and analytical characterization. Technical documentation should clearly identify the API as recombinant human interleukin-11 and include its CAS number, UNII, molecular mass, amino-acid length, expression system and biological classification.
For pharmaceutical development and API evaluation, particular attention should be given to identity, purity, potency, aggregation and process-related impurities. A product-specific certificate of analysis and validated analytical specification should be used for final release decisions.
Oprelvekin therefore represents a specialized recombinant protein API rather than a conventional chemically synthesized pharmaceutical ingredient. Its documentation should reflect the analytical and regulatory principles applicable to biotechnology-derived products.
| 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% |
| Individual Impurity | NMT 0.5% |
| Total Impurities | ≤ 1.5% |
| Water Content | NMT 0.5% |