An experimental drug has enabled overweight or obese people to lose about 22.5 percent of their body weight, about 52 pounds on average, in a large trial, the drug’s maker announced Thursday.
The company, Eli Lilly, has not yet submitted the data for publication in a peer-reviewed medical journal or presented it in a public setting. However, the claims surprised medical experts.
“Wow (and a double Wow!),” wrote Dr. Sekar Kathiresan, CEO of Verve Therapeutics, a company that focuses on drugs for heart disease. in a tweet. Drugs like Eli Lilly’s, he added, “are really going to revolutionize the treatment of obesity!”
Dr. Kathiresan has no ties to Eli Lilly or the drug.
Dr. Lee Kaplan, an obesity expert at Massachusetts General Hospital, said the drug’s effect “appears to be significantly better than any other anti-obesity drug currently available in the US.” The results, he added, are “very impressive.”
Dr. Kaplan, who consults with a dozen pharmaceutical companies, including Eli Lilly, said he was not involved in the new trial or in the development of this drug.
On average, study participants weighed 231 pounds at the start and had a body mass index, or BMI, a commonly used measure of obesity, of 38. (Obesity is defined as a BMI of 30 or higher.)
At the end of the study, those taking the highest doses of Eli Lilly’s drug, called tirzepatide, weighed about 180 pounds and had a BMI just below 30, on average. The results far exceed those typically seen in weight-loss drug trials and are typically only seen in surgical patients.
Some trial participants lost enough weight to get into the normal range, said Dr. Louis J. Aronne, director of Weill Cornell Medical Center’s comprehensive weight management program, who worked with Eli Lilly as the study’s principal investigator.
Most people in the trial did not qualify for bariatric surgery, which is reserved for people with a BMI over 40, or those with a BMI of 35 to 40 with sleep apnea or type 2 diabetes. The risk of developing diabetes it is many times higher for people with obesity than for people without.
Because obesity is a chronic medical condition, patients should take tirzepatide for life, as they do for blood pressure or cholesterol medications, for example.
Dr. Robert F. Kushner, an obesity expert at Northwestern University Feinberg School of Medicine and a paid consultant for Novo Nordisk, said the new drug, along with a similar but less effective one from Novo Nordisk, may close the so-called gap. of treatment.
Diet and exercise, combined with previous obesity medications, typically produce a 10 percent weight loss in patients. That’s enough to improve health, but not enough to make a big difference in the lives of obese people.
The only other treatment is bariatric surgery, which can result in substantial weight loss. But many people are not eligible or just don’t want the surgery.
With Eli Lilly’s drug and Novo Nordisk’s recently approved semaglutide, “we’re really on the cusp of a new form of treatment,” Dr. Kushner said.
But prices can be a barrier. Insurance companies often don’t pay for weight-loss drugs. The drug from Novo Nordisk, whose trade name is Wegovy, has a list price of $1,349.02 per month.
Experts worry that tirzepatide, if approved, could be priced in the same range. Many people who could benefit most from weight loss may not be able to afford such expensive medications.
The Eli Lilly study lasted 72 weeks and involved 2,539 participants. Many qualified as obese, while others were overweight but also had risk factors such as high blood pressure, high cholesterol levels, cardiovascular disease or obstructive sleep apnea.
They were divided into four groups. All received dietary advice to reduce their calorie intake by about 500 a day.
One group was randomly assigned to take a placebo, while the other three received doses of tirzepatide ranging from 5 to 15 milligrams. The patients injected the drug once a week.
Those who took the higher dose lost more weight, the researchers found. Participants taking a placebo lost 2.4 percent of their weight, an average of 5 pounds, typical for a diet study.
Dr. Nadia Ahmad, senior medical director of Eli Lilly’s obesity program, said seeing the results was an emotional moment for her.
“I don’t think I ever imagined that we could achieve this degree of weight loss with a drug,” he said. “We only got so far with the surgery.”
For decades, people who were overweight or obese were told that solving the problem was up to them. Diet and exercise were the prescriptions, and they just didn’t work for many people. Most tried diet after diet, only to gain back the weight they lost.
Last year, the situation began to change when Novo Nordisk received approval from the Food and Drug Administration to market semaglutide. The drug can cause 15 to 17 percent weight loss in people with obesity.
The drugs are in a new class of drugs called incretins, which are natural hormones that slow stomach emptying, regulate insulin, and decrease appetite. Side effects include nausea, vomiting, and diarrhea. But most patients tolerate or are not bothered by these effects.
Incretins raise the bar for the type of weight loss possible with medication. But they also raise difficult questions about whether bariatric surgery is becoming a relic of the past. New versions of incretins are already in development that could be even more powerful than Eli Lilly’s drug.
Even without them, Dr. Aronne said, the reductions seen with the Eli Lilly drug are “squarely in the range of surgical weight loss.”
Some patients who have undergone bariatric surgery describe mixed results. Sarah Bramblette, a board member of the Obesity Action Coalition, underwent bariatric surgery just to regain the weight.
Now 44, he weighed 500 pounds when he had the operation 20 years ago, dropping to 250 pounds. However, over the years, his weight climbed back up to 490 pounds. He needed heart surgery, but he was too heavy for the operating table. Diets, and he has tried them repeatedly, did not help.
Semaglutide from Novo Nordisk allowed him to drop to 430 pounds. Now, Ms. Bramblette said, she would like to try the Eli Lilly drug if it were available.
“Trust me, I wouldn’t choose to be this size,” said Ms Bramblette. “I need to lose weight.”