Table 1 Classes of approved recombinant-protein drugs [1].

Hormones

Insulin (e.g., Humulin), glucagon (e.g., Glucagen), human growth hormone (e.g., Humatrope), thyrotropin (Thyrogen), follicle-stimulating hormone (Gonal-F), lutelnizing hormone (lutropin alfa [Luveris]), human chorionic gonadotropin (Ovidrel), erythropoietin (e.g., epoctin alfa [Epogen])

Cytokines

Interferon alfa (e.g., Roferon-A), granulcyte-colony-stimulating factor (filgrastim [Neupogen]), interleukin (e.g., aldesleukin [Proleukin])

Clotting factors

Factor VII (NovoSeven), factor VIII (e.g., Kogenate), factor IX (BeneFIX)

Monoclonal antibodies

Antibodies to vascular endothelial growth factor (bevacizumab [Avastin]), epidermal growth factor receptor (cetuximab [Erbitux]), GPIIb/IIIa receptor (abciximab [ReoPro]), CD20 (rituximab [Rituxan]), and TNF-α (e.g., infliximab [Remicade])

Vaccine products

Hepatitis B surface antigen (e.g., Recomblvax HB), Borrelia burgdorferi outer sourface protein A (LYMErix), + human papillomavirus major capsid proteins (Gardasil)

Enzymes

Glucocerebrosidase (Cerezyme), DNase (Pulmozyme), thrombolytics (e.g., alteplase [Activase]), urate oxidase (rasburicase, Elitek)

Ovel synthetic proteins

Fusion protein of interleukin-2 and diphtheria toxin (denileukin diftitox [Ontak]), soluble TNF receptor linked to IgG Fc (etanercept [Enbrel])

Novel conjugates

Pegylated proteins: interferon (peginterferon alfa-2a [Pegasys]), granulocyte colony-stimulating factor (pegfilgrastim [Neulasta]), human growth hormone (pegvisomant [Sornavert])

Covalently attached metal chelators: ibrutumomab tiuxetan (Zevalin)

Covalently attached radioactive iodine: Iodine-131 tositumomab (Bexxar)

Covalently attached chemotherapeutics: gemtuzumab ozogarnicin (Mylotarg)