Inside insulin (Part 2): Approaching a cure for type 1 diabetes?


CGMs and automated insulin delivery: A ‘godsend’

A huge change has also been seen, most notably in the past 15 to 20 years, in the technological advancements that can help those with type 1 diabetes live an easier life.

Continuous glucose monitors (CGMs) and automated ways of delivering insulin, such as smart pens and insulin pumps, have made the daily life of a person with type 1 diabetes in the Western world considerably more comfortable.

CGMs provide a constant stream of data to an app, often wirelessly in sync with the insulin pump. However, on a global level, they are only available to a lucky few.

In England, pending National Institute for Health and Care Excellence) approval, any CGM should be available to all eligible patients with type 1 diabetes within the NHS from April 2022, Dr. Kar pointed out. In the United States, CGMs are often unaffordable and access is mostly dependent on a person’s health insurance.

Kersten Hall, PhD, a scientist and U.K.-based medical historian who recently wrote a book, “Insulin, the Crooked Timber” (Oxford, England: Oxford University Press, 2022) uncovering the lesser-known story behind the discovery of insulin, was diagnosed with adult-onset type 1 diabetes at the age of 41. Dr. Hall had always found the finger-prick blood glucose test to be a chore but now has a CGM.

“It’s a total game changer for me: a godsend. I can’t sing its praises enough,” he said. “All it involves is the swipe of the phone and this provides a reading which tells me if my glucose is too low, so I eat something, or too high, so I might [go for] a run.”

Brewing insulin at scale

As described by Dr. Hall in his book, the journey from treating Mr. Thompson in 1922 to treating the masses began when biochemist James Collip, MD, PhD, discovered a means of purifying the animal pancreas extracts used to treat the teenager.

But production at scale presented a further challenge. This was overcome in 1924 when Eli Lilly drew on a technique used in the beer brewing process – where pH guides bitterness – to purify and manufacture large amounts of insulin.

By 1936, a range of slower-acting cattle and pig-derived insulins, the first produced by Novo Nordisk Pharmaceuticals, were developed.

However, it took 8,000 lb (approximately 3,600 kg) of pancreas glands from 23,500 animals to make 1 lb (0.5 kg) of insulin, so a more efficient process was badly needed.

Dr. Hall, who is a molecular biologist as well as an author, explains that the use of recombinant DNA technology to produce human insulin, as done by Genentech in the late 70s, was a key development in the story of modern insulin products. Genentech then provided synthetic human insulin for Eli Lilly to conduct clinical trials.

Human insulin most closely resembles porcine insulin structure and function, differing by only one amino acid, while human insulin differs from bovine insulin by three amino acid residues. This synthetic human insulin eliminated the allergies that the animal-derived products sometimes caused.

In the early 1980s, Eli Lilly produced Humulin, the first biosynthetic (made in Escherichia coli, hence the term, “bio”) human insulin.

This technology eventually “allowed for the alteration of specific amino acids in the sequence of the insulin protein to make insulin analogs [synthetic versions grown in E. coli and genetically altered for various properties] that act faster, or more slowly, than normal human insulin. By using the slow- and fast-acting insulins in combination, a patient can control their blood sugar levels with a much greater degree of finesse and precision,” Dr. Hall explained.

Today, a whole range of insulins are available, including ultra–rapid-acting, short-acting, intermediate-acting, long-acting, ultra–long-acting, and even inhaled insulin, although the latter is expensive, has been associated with side effects, and is less commonly used, according to Dr. Stephens.

Oral insulin formulations are even in the early stages of development, with candidate drugs by Generex and from the Oralis project.

“With insulin therapy, we try to reproduce the normal physiology of the healthy body and pancreas,” Dr. Stephens explained.

Insulin analogs are only made by three companies (Eli Lilly, Novo Nordisk, and Sanofi), and they are generally much more expensive than nonanalog human insulin. In the United Kingdom through the NHS, they cost twice as much.

In the United States today, one of the biggest barriers to proper care of type 1 diabetes is the cost of insulin, which can limit access. With the market controlled by these three large companies, the average cost of a unit of insulin in the United States, according to RAND research, was $98.17 in January 2021, compared with $7.52 in the United Kingdom and $12.00 in Canada.

Several U.S. states have enacted legislation capping insulin copayments to at, or under, $100 a month. But the federal Build Back Better Framework Act – which would cap copayments for insulin at $35 – currently hangs in the balance.

Alongside these moves, in 2020 the Food and Drug Administration approved the first interchangeable biosimilar insulin for type 1 diabetes (and insulin-dependent type 2 diabetes) in children and adults, called Semglee (Mylan Pharmaceuticals).

Biosimilars (essentially generic versions of branded insulins) are expected to be less expensive than branded analogs, but the indications so far are that they will only be around 20% cheaper.

“I totally fail to understand how the richest country in the world still has a debate about price caps, and we are looking at biosimilar markets to change the debate. This makes no sense to me at all,” stressed Dr. Kar. “For lifesaving drugs, they should be funded by the state.”

Insulin also remains unaffordable for many in numerous low- and middle-income countries, where most patients pay out-of-pocket for medicines. Globally, there are estimated to be around 30 million people who need insulin but cannot afford it.

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