Looking at a list of the many types of insulin available today is impressive, but there’s even more to the story. Overall, patterns of insulin use have changed dynamically during the past six years.
Use of Regular insulin has been on the decline since Humalog (insulin lispro), the first rapid-acting insulin, was released in August 1996. While it’s taken a few years for rapid-acting insulins to outsell the short-acting Regular, the long-acting Lantus (insulin glargine) has been on a rapid climb as a basal insulin since its release in the United States in May 2001.
It took about five years for sales of rapid-acting insulin to overtake Regular. “Medically, it’s been a slow transition,” says John Holcombe, MD, medical adviser for Lilly USA, about the move to Humalog. “While endocrinologists quickly adopted Humalog, the rest of the medical community, which cares for most people with diabetes, has been slower to adopt rapid-acting insulin.”
Eli Lilly and Co. saw sales of Regular begin to decline while sales of Humalog increased after its introduction in 1996. In 2001, Holcombe observes, “the lines crossed,” and Humalog now outsells Regular insulin.
“It’s been highly successful,” says David Kliff, publisher of the Diabetic Investor, which provides research focusing on the business side of diabetes. “It has almost fourteen percent of the insulin market and thirty-four percent of the long-acting and intermediate-acting insulin market. I think it will continue to do very well.”
Charles H. Raine III, MD, a diabetologist in Orangeburg, South Carolina, is one who quickly adopted the new insulins for his patients.
“I use more and more of the analog insulin—Humalog, Lantus and Novo-Log [insulin aspart]. I use very little Regular insulin since the rapid-acting insulins have been available. There is less hypoglycemia and better meal coverage with Humalog and Novo-Log.”
Are Regular and NPH on the Way Out?
While diabetes specialists are increasingly adopting the newer insulin analogs, Regular and NPH insulin are not on their way out. They still have their uses, argues Howard Wolpert, MD, senior physician for the Joslin Clinic in Boston, Massachusetts.
“Humalog or NovoLog doesn’t cut it when you’re having pizza or a hamburger,” Wolpert explains. For those and other fatty foods, which are digested more slowly, the slower action of Regular is more likely to help you maintain better control.
Also in some people, Wolpert adds, especially those with delayed stomach emptying, rapid-acting insulin may begin taking effect before carbohydrates are absorbed in the body, causing hypoglycemia.
As for NPH, it can play a role in helping to eliminate dawn phenomenon and is also useful for people who don’t have time, or don’t choose, to take a lunchtime injection. A shot of NPH in the morning, and they’re good to go for lunch.
Wolpert tells of college students who take Lantus as their basal insulin “because their waking times vary. Some are then taking NPH in the morning to cover lunch.”
“It’s a matter of individualizing,” he says, adding that physicians need to consider age, complications, lifestyle and other factors when prescribing an insulin regimen.
Raine also sees a use for NPH in the admittedly anecdotal 20 percent or so of those for whom Lantus fails to last a full 24 hours.
“Lantus is a great basal insulin in about eighty percent of people,” Raine says. “In the other twenty percent, it [drops off] in fifteen to eighteen hours. We are using it [twice a day] in some people. I’m not sure that it is superior to twice-daily NPH in that instance. That can make the cost prohibitive—about sixty dollars a vial [for Lantus] around here.”
The Market Outlook
The market for insulin is increasing, too. According to figures from IMS Health, a healthcare information company that collects data on prescription sales, total insulin sales in the United States rose from $1.2 billion in 1999 to nearly $1.6 billion in 2001 (the latest year for which figures are available).
It’s probably no surprise that insulin sales are on the rise. Diabetes itself is increasing at epidemic rates.
“Diabetes is expanding at an alarming rate,” Holcombe notes. “It used to be gradual—about a one to two percent increase per year. Today, it’s like six to ten percent a year. There were ten percent more cases this January than there were last January.”
More Insulins Are on the Way
If you think the insulin market has reached its zenith, think again. Look for at least two more insulins to reach the market in the next three years.
Novo Nordisk submitted a New Drug Application to the U.S. Food and Drug Administration on December 9, 2002, for insulin detemir, a long-acting insulin analog.
Detemir, the company states, “is designed to provide an improved basal insulin profile which is smoother, longer-acting and with less day-to-day variation than conventional NPH insulin preparations.”
Also look for a new short-acting insulin—called No. 1964, for the time being—from Aventis, the maker of Lantus, reports David Kliff, who publishes the Diabetic Investor. He expects this short-acting insulin to be on the market within three years.
Kliff also predicts a heightened emphasis on blended insulins.
“The insulin market,” he asserts, “is going to be a whole new market in three years.”