Human growth hormone production

Occasionally anecdotal data come to light on the cash outlays required for the development of specific NCEs. For example, in depositions filed for a patent infringement lawsuit, Genentech claimed it had spent 45 million to develop Protropin , its human growth hormone product, (494) and Eli Lilly certified that it had spent 16 million between 1980 and 1987 on its effort to develop its version of the drug (495). In another example, a 1980 report of the development cost of an oral systemic drug for chronic use estimated 21 million in outlays in the clinical period (226). Unfortunately, anecdotal estimates of this kind do not help verify industrywide costs, because they are self-selected and do not reflect the cost of failures or basic research. 

Therapeutics. Therapeutic materials represent a class of polypeptides that are a low volume, high value product. The production system need not be very efficient but the quaHty of the recombinant protein has to be extremely pure (33,34). Thus high cost mammalian production systems can be tolerated. However, some of the therapeutic proteins such as insulin, human growth hormone, interleukins, interferon, and streptokinase are produced microbially. 

Human growth hormone was originally manufactured by isolation of the natural product from human pituitaries and subsequent purification of the protein. Since 1985, manufacture of hGH has been almost exclusively by recombinant DNA technology. 

Biotechnology era beginning First recombinant DNA products Human insulin Human growth hormone Interferons, etc. Monoclonal antibodies Nucleotide blockage Growth in use of natural products and neutraceuticals... 

The current potency assay used for human growth hormone (hGH) products is performed with hypo-physectomized rats and measures weight gain over 7 days in response to intact hGH. The assay utilizes many rats, is labor intensive, and the results can be... 

Kajino, T., Saito, Y., Asami, O. etal. (1997) Extracellular production of an intact and biologically active human growth hormone by the Bacillus brevis system. Journal of Industrial Microbiology Biotechnology, 19 (4), 227-231. 

It overcomes problems of product safety. Direct extraction of product from some native biological sources has, in the past, led to the unwitting transmission of disease. Examples include the transmission of blood-borne pathogens such as hepatitis B and C and human immunodeficiency virus (HIV) via infected blood products and the transmission of Creutzfeldt-Jakob disease to persons receiving human growth hormone (GH) preparations derived from human pituitaries. 

Examples of the early application of recombinant DNA technology in medicine are the development of recombinant human growth hormone human insulin human interferons, thought to have anticancer activity in addition to antiviral activity interleukins (regulatory proteins from lymphocytes that are believed to be important in the treatment of immunodeficiency diseases and cancer) tumor necrosis factor epidermal and bone marrow progenitor cell growth factors and the production of vaccines (Table 12.1). 

Although gradient elution is generally required for RPLC separations of proteins, isocratic elution can be successful in some instances. For example, isocratic elution has been used for the determination of purity of production batches of biosynthetic human growth hormone (HGH).42 The method was used to... 

Figure 4.12 Analysis of biosynthetic human growth hormone by isocratic reversed-phase chromatography. To generate all possible degradation products, a production lot of HGH was exposed to 40°C. The profile of the unstressed HGH is shown in the upper trace. (Reproduced from R.M. Riggin, G.K. Dorulla, and DJ. Miner, Anal. Biochem., 167 199 [1987]. With permission from Elsevier Science.)...

Human growth hormone (hGH) is a polypeptide with 191 amino acids. It is secreted by the pituitary gland. This hormone stimulates the production of insulin-like growth factor-1 (IGF-1) from the liver. Most of the positive effects of hGH are mediated by the IGF-1 system, which also includes specific binding proteins. 

DKPs are simple and easy to obtain and are quite common by-products of synthetic, spontaneous, and biological formation pathways. DKP formation has been well documented as side reactions of solid-phase and solution-phase peptide synthesis. In addition, DKPs have been shown to be decomposition products of various peptides, proteins, and other commercial pharmaceuticals. Cyclic dipeptides were found to be present in solutions of human growth hormone, bradykinin, histerlin, and solutions of agents within the classes of penicillins and cephalosporins. " DKPs are also enzymatically synthesized in several protists and in members of the plant kingdom. Hydrolysates of proteins and polypeptides often contain these compounds and they are commonly isolated from yeasts, lichens, and fungi. ... 

In some ways, the use of animals (almost always mammals) as substitutes for bacteria in the recombinant DNA production of drugs is a natural and obvious extension of the techniques originally developed for the manufacture of insulin, human growth hormone, and other pharmaceuticals. Live animals have a built-in production... 

Genenteeh was founded in 1976 by scientist Herbert Boyer and the venture capitalist, Robert Swanson. Headquartered in San Francisco, it employs almost 5000 staff worldwide and has 10 protein-based products on the market. These include human growth hormones ( Nutropin , Chapter 8), the antibody-based products Herceptin and Rituxan (Chapter 10) and the thrombolytic agents Activase and TNKase (Chapter 9). The company also has 20 or so products in clinical trials. In 2001, it generated some US 2.2 billion in revenues, 24% of which it reinvested in R D. 

Table 1.10. Some pharmaceutical substances originally isolated from animal sources. While some are still produced by direct extraction from the native source, others are now also produced by direct chemical synthesis (e.g. peptides and some steroids), or by recombinant DNA technology (most of the pol5 peptide products). Abbreviations hGH = human growth hormone FSH=follicle stimulating hormone hCG=human chorionic gonadotrophin HSA=human serum albumin HBsAg=hepatitis B surface antigen...

Figure 8.14. Production of recombinant human growth hormone (rhGH) in E. coli (as an intracellular protein). Subsequent to fermentation, the cells are collected by centrifugation or filtration. After homogenization, nucleic acids and some membrane constituents are precipitated by the addition of polyethyleneimine. Ammonium sulphate precipitation of the supernatant concentrates the crude rhGH preparation. Chromatographic purification follows, as illustrated...

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