Palifermin is a recombinant human keratinocyte growth factor (KGF) and a biotechnology-derived protein used as supportive therapy for the prevention and reduction of severe oral mucositis associated with intensive cancer treatment. It is a truncated recombinant form of human KGF, also known as fibroblast growth factor 7 (FGF-7). Palifermin is produced using recombinant DNA technology in Escherichia coli.
Palifermin differs from endogenous human KGF because the first 23 N-terminal amino acids are deleted, producing a 140-amino-acid recombinant protein with improved protein stability. FDA and DailyMed describe palifermin as a water-soluble 140-amino-acid protein with a molecular weight of 16.3 kDa.
Palifermin binds to the keratinocyte growth factor receptor (KGFR/FGFR2-IIIb) expressed primarily on epithelial cells. Receptor activation stimulates epithelial-cell proliferation, differentiation, migration and cytoprotective mechanisms.
This biological activity helps protect and regenerate epithelial tissues that can be damaged by high-dose chemotherapy and radiotherapy. The pharmacological effect is therefore based on specific receptor-mediated biological activity, making potency an important quality attribute for the recombinant protein API.
Palifermin is used to decrease the incidence and duration of severe oral mucositis in appropriate patients receiving intensive cytotoxic therapy requiring hematopoietic stem-cell support. FDA documentation identifies the approved product Kepivance (palifermin) as an intravenous biological product.
The current DailyMed presentation describes Kepivance as a sterile, preservative-free, lyophilized powder. Reconstitution with 1.2 mL Sterile Water for Injection produces a clear, colorless solution at 5 mg/mL with a pH of 6.5. The current presentation contains 5.16 mg palifermin per vial.
Palifermin is manufactured through recombinant biotechnology using E. coli. FDA's original chemistry review describes the product as a highly purified and well-characterized recombinant KGF and states that manufacturing controls, product characterization, specifications, stability and process validation were evaluated as part of the BLA review.
As a recombinant protein, Palifermin requires a biological-product quality-control strategy. Relevant attributes include protein identity, purity, protein concentration, aggregation, degradation products, biological potency, host-cell proteins, residual host-cell DNA, endotoxin and sterility for the appropriate pharmaceutical presentation.
Palifermin is a water-soluble protein. The approved pharmaceutical product is supplied as a white, preservative-free lyophilized powder. Following reconstitution, the solution is clear and colorless.
The current DailyMed label identifies the active ingredient amount as 5.16 mg/vial, together with mannitol, sucrose, L-histidine and polysorbate 20 as formulation excipients. The reconstituted product has a concentration of 5 mg/mL.
Because Palifermin is a recombinant protein rather than a conventional small-molecule chemical, parameters such as melting point, residue on ignition and specific rotation are not appropriate routine release specifications.
The most relevant analytical controls are protein identity, purity, concentration and biological activity, supported by orthogonal analytical characterization. Numerical acceptance limits for many commercial drug-substance attributes are not publicly disclosed in FDA labeling, so they should not be fabricated for a CMS product page.
| 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 0.2% |
| Heavy Metals | NMT 10 ppm |
| pH (1% Solution) | 2.0 – 4.0 |
| Individual Impurity | NMT 0.5% |
| Total Impurities | ≤ 1.5% |