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Back in the 1920s, scientists discovered that insulin, the hormone that regulates blood sugar, could keep diabetes under control. The disease had basically been a death sentence before then. Today, many people still suffer with diabetes because they can't afford the insulin needed to treat it. A doctor in Maryland has been trying to understand why. NPR's Anders Kelto has the story.
ANDERS KELTO, BYLINE: Dr. Jeremy Greene sees a lot of patients with diabetes.
DR. JEREMY GREENE: Diabetes, it is really just out of control with their glucoses very, very high. Sometimes so high that you can't even record the number on the glucometer.
KELTO: And the reason they can't control their blood sugar, they tell them, is that insulin is too expensive. Greene, who teaches medicine and history of medicine at Johns Hopkins, called up some pharmacies in Baltimore. He asked them about low-cost versions of insulin.
GREENE: And only then realized that there was no such thing as generic insulin in the United States in the year 2015.
KELTO: He wanted to know why that was. So he dug into the history of insulin and has now published his findings in the New England Journal of Medicine. What he found is a long line of small improvements to insulin over many years. The first insulin was exacted from cows and pigs. Purification techniques improved. Then it was made to last longer in the blood stream.
GREENE: And all of these innovations helped to make insulin a little bit safer, helped to make it a little bit more effective.
KELTO: And probably kept prices up. Then scientists figured out how to make human insulin by inserting the gene into bacteria. And then, Greene says, a funny thing happened.
GREENE: The older insulins, rather than remaining around on the market as cheaper, older alternatives to this newer and slightly better insulin, disappear from the market.
KELTO: Greene says there's no one reason why they disappeared. But clearly, companies didn't think they would be profitable. Greene's co-author on the new paper. Dr. Kevin Riggs from Johns Hopkins says they're disappearance probably had to do with doctors being influenced by marketing.
DR. KEVIN RIGGS: A lot of times, we get caught up in some of the hype. When a new medicine comes out and it has theoretical advantages, you know, we buy into that. And we think that newer is better.
KELTO: But newer isn't always better, says Dr. Adriane Fugh-Berman. She's a professor of medicine and pharmacology at Georgetown University.
DR. ADRIANE FUGH-BERMAN: In studies that that have compared older drugs to newer drugs, often older drugs actually come out looking better or equal to newer drugs.
KELTO: For example, she says, look at insulin.
FUGH-BERMAN: Some patients have found that animal-derived insulins work better for them, that they cause less variability in blood sugar, for example, maybe less episodes of hypoglycemia.
KELTO: Those older versions of insulin aren't available in the U.S. anymore, but they are available in other countries.
FUGH-BERMAN: In Canada, there actually is still an animal-derived insulin on the market. And that was really due to the efforts of consumer advocates.
KELTO: As older forms of insulin have vanished in the U.S., newer forms have remained expensive. The drug now costs up to $400 a month. And because of that high cost, many of the estimated 29 million Americans with diabetes can't afford it. Jeremy Greene says it's not fair to blame industry for all of this.
GREENE: We don't believe that there is a conspiracy to keep insulin expensive.
KELTO: But he points out a problem. There's a huge demand for low-cost insulin and yet there's no supply. And he says while innovations in insulin over the past 90 years have really been significant, it's important to ask this question.
GREENE: Do these innovations merit the loss of affordable insulin?
KELTO: For patients at his clinic who can't afford insulin, Greene says, the answer is clear - a less expensive option is needed. Anders Kelto, NPR News, Washington. Transcript provided by NPR, Copyright NPR.