The price of insulin, a drug that's been around for nearly a century, has been steadily rising, surpassing the cost of similar treatments and becoming an increasingly unaffordable necessity for the roughly 6 million Americans with diabetes. And in this case, innovation may be to blame.
The average price of insulin per milliliter rose from $4.34 in 2002 to $12.92 in 2013, according to the findings of a study published Tuesday in JAMA. The annual cost for patients to use the treatment during that same period rose from $231 in 2002 to $736 in 2013.
By comparison, researchers found that the average price of DPP-4 inhibitors, a class of diabetes medication that was introduced to the U.S. market in 2006 and is used to control blood glucose levels in type 2 diabetes patients, increased by 34% from $6.67 in 2006 to $8.92 in 2013.
And in fact, the price of metformin, an oral medication to control glucose levels in type 2 diabetes patients, fell by 93% from $1.24 per tablet in 2002 to 31 cents in 2013.
Researchers point to the evolution of insulin, which is the most popular treatment for type 2 diabetes, as one of the reasons why its price has spiked.
According to the American Diabetes Association, there are over 20 types of insulin sold in the U.S.
“Pricing has really reflected the benefits of the newer insulins, but I think it's sort of gone out of control,” said the study's co-author, Dr. William Herman, a professor of epidemiology at the University of Michigan's School of Public Health.
In the 1920s, Canadian researchers discovered insulin could be extracted from cattle and pigs for use in humans.
Over time, advances in research allowed for purer forms of insulin to be produced. These made the drug last longer and offered fewer adverse reactions. The 1970s brought a synthetic human insulin that used recombinant DNA technology. In the 1980s, synthetic “analog” insulins mimicked the body's natural pattern of insulin release.
All that innovation led to decreased production of the older, animal-based version. And that limited supply, Herman said, is why insulin prices have risen.
The nation's top manufacturers of insulin are Novo Nordisk and Eli Lilly and Co., whose top-selling insulin drug, Humalog, generated $2.8 billion in sales last year.
Often, the listed price of a drug is not the price insurers and pharmacy benefits managers pay, both of whom negotiate substantial discounts. Insured patients often pay just a copay.
And according to a 2014 JAMA study, out-of-pocket costs have also increased from an average of $19 per prescription in 2000 to $36 by 2010. Most of that hike comes as a result of patients switching to a newer version of the insulin.
Researchers wrote then that they found a spike in the use of insulin analogs among privately insured patients with type 2 diabetes. They did not identify a specific clinical value of that switch.
Another reason for the rise in insulin prices could be that drugmakers are girding themselves for the pending price competition expected to come with the introduction of biosimilar treatments to the U.S. market. Some say the biologic copycats could provide discounts of up to 40%.
“No one expects to see the magnitude of price competition that we see among the small molecule generic products,” said Dr. Caleb Alexander, co-director of the Center for Drug Safety and Effectiveness at the Johns Hopkins Bloomberg School of Public Health.
“With that said, biosimilars are looming on the horizon, and so that raises the specter that there will be significantly greater competition in the market that I think may drive manufacturers to try to generate as much return on their investments as they can at the current time,” he said.
