IGF, a polypeptide chin composed of 70 amino acids with 3 intramolecular disulfide bridges and a molecular mass of 7649 Daltons has a structure similar to insulin. Occurring in blood and cerebral spinal fluid, it is produced by most tissues especially the liver. IGF functions mainly to mediate effects of Growth Hormone (GH) (www. pdrhealth. com/drug. info. nmdrugs/profiles/nutsupdrugs/ins_0303. shtml) IGF (somatomedin or sulfation factor) is known by the trade names Increlex (mecasermin, rhIGF and Ipelex rhIGF and IGFBP3). (Salmon and Daughaday, 1957)
Therapeutic uses of IGF IGF preserves function and promotes growth of neurons and can be used to treat Amyotrophic Lateral Sclerosis (ALS), a condition of progressive motor neuron degradation. Death occurs as a result of other infections that plague the body’s immunity. (www. medicinenet. com/amyotrophic_lateral_sclerosis/article. htm). This use is still under clinical trials but is promising due to IGF’s trophic effect on neurons and muscle cells. IGF is necessary for normal growth levels. Consequently, IGF primarily treats abnormal shortness in children.
Initially, this was treated with GH, the problem may not always be GH deficiency rather; it could be GH resistance or IGF deficiency (IGFD) (www. tercica. com/). IGF causes the uptake of glucose by cells hence the belief that it can be used to treat Type I and II diabetes. (Scheiweiller et al, 1999 and, www. aurogen. com) Glucose regulation is deranged in diabetes due to insulin deficiency or insulin resistance. If poorly managed hypoglycemic episodes occur and the patient is predisposed to complications such as cardiovascular disease, retinopathies, nephropathies and neuropathies (www.
diabetes. org/) History of development Evaluations of IGF efficacy in diabetes were initially promising but Genentech stopped the program due to worsening of diabetes retinopathies following the treatment. The company however gave up due to manufacturing difficulty, difficult regulations and a desire to focus on oncology (Fisher, 2004). Dr Clark was at the time working with Genentech to develop IGF-1 as a drug left the company when the program was halted but returned later to request licensing of IGF-1 for Tercica, a company he founded.
He was granted the rights, clinical data of 15 years and 20 years of patents from Genentech. He was also given a workforce of several employees to help him get started. In return Genentech got a percentage of the sales of IGF. Manufacturing process IGF-1 is manufactured following recombinant DNA technology. The sequence of a gene coding for a protein is isolated. The gene sequence is then spliced into a cell line (yeast or bacteria) which is reproduced rapidly in fermentation tanks (www. gropep. com/). After being produced in the periplasmic space of the Escherichia coli cells, the protein is isolated.
It then undergoes refolding under controlled conditions for restoration to its active biological form. Finally it is purified by column chromatography and ultra filtration. The drug substance, once purified is ready for formulation into the final product. (www. emea. europa. eu/humandocs/PDFs/EPAR/increlex/H-704-en6. pdf). Ownership rights of the drug Genentech initially owned the right to the drugs (www. gov. uspto. gov/). It later licensed them to Tercica which manufactures Increlex. Insmed made the drug IGF and called it Iplex, but Tercica sued Insmed for infringement of patent rights seeking a ban on sales of Iplex.
(Pollack, 2007). Insmed withdrew Iplex from the market leaving Increlex as the only version of IGF- 1 in the U. S. In Australia ownership rights of the rhIGF drug are possessed by Gropep, a publicly listed company that develops, manufactures and sells proteins for biomedical research (www. gropep. com). Genentech, Tercica and Insmed are biotechnology companies which develop and commercialize medicine to treat metabolic and endocrine disorders. Genentech however has a greater interest in oncology. They are all publicly listed companies. (www. insmed. com/) (www. tercica. com/) (www.gene.com/)