I recently came across an article about biosimilar insulins and was quite surprised to learn about the potential problems we and our patients may face with future insulin products.
Although I do not know of any biosimilar insulins yet in the United States, this issue is very important “because impure proteins {in biosimilar insulins} may be recognized by the body as foreign and stimulate the generation of antibodies. These occasionally can cause allergic reactions, and the allergy can become generalized to attack the body’s own insulin. Furthermore, production of lots of antibodies can neutralize the effectiveness of insulin itself, which then loses efficacy.” We saw that happen with beef insulin and beef/pork insulins in the past.
Here are some alarming facts from the article by Philip Home in Sept 2011 issue of Diabetes Voice:
In 1980, the major technical advance occurred when” bacteria and yeast were bioengineered with the genes that included the template for human insulin. The cell culture process then multiplies the bacteria/yeast while the genes are turned on to produce the insulin precursor….From these, the insulin must be extracted and purified to remove all the bacterial/yeast proteins and other biochemical molecules, before being processed to derive the insulin from the precursor protein.”
“As modern insulins come off patent, many companies are expected to try to enter the market with copies of current branded insulin called biosimilar insulins.”
It is important to note that “chemical medications like metformin and simvastatin, have a defined chemical structure” It is not difficult to show regulators that the chemical they produce is the same as the original” (Of course, as we know, the delivery of the medication may not be the same as the branded original version of any medications)
“Proteins like insulin are different. They are built from a small number of identical small molecules (amino acids), the same ones often being used many times over, but in a critically important order. The molecule then folds in complex ways which are necessary to its biological action. Showing that a protein molecule like insulin has the right number of amino acid components is easy, but showing that they are all in the right order, and that the molecule is folded correctly, is very difficult.”
“If a small amount of a manufactured protein is not perfect, then it may cause the production of antibodies with repeated injection in patients, and demonstrating that such impurities do not exist in very small proportions is well-nigh impossible.”
Those are the reasons that “drug regulators do not refer to ‘generic insulin’ (as they do for generic medications like metformin) but have introduced the term ‘biosimilar insulin’.”
Currently during 2011-2013 “several important insulin analogues used in diabetes care are coming off patent, including insulins aspart, glargine, and lispro. Manufacturers in America, China, India, Israel and the UK are known to be interested in producing and marketing biosimilar insulins, insulin glargine being the principle target.”
“Meanwhile, the development of new insulins continues, so new premium priced products are already in advanced development from some insulin manufacturers”
An important issue will be “whether a pharmacist faced with a physician’s prescription can, or can be required to, substitute a cheaper version of the same insulin for the branded insulin a person with diabetes has been using.”
n that Regulators will only it to be labeled “similar” — not identical. Hence, biosimilar insulins."
