An experimental drug has enabled individuals with weight problems or who’re chubby to lose about 22.5 p.c of their physique weight, about 52 kilos on common, in a big trial, the drug’s maker introduced on Thursday.

The firm, Eli Lilly, has not but submitted the info for publication in a peer-reviewed medical journal or offered them in a public setting. But the claims nonetheless amazed medical specialists.

“Wow (and a double Wow!)” Dr. Sekar Kathiresan, chief government of Verve Therapeutics, an organization specializing in coronary heart illness medication, wrote in a tweet. Drugs like Eli Lilly’s, he added, are “truly going to revolutionize the treatment of obesity!!!”

Dr. Kathiresan has no ties to Eli Lilly or to the drug.

Dr. Lee Kaplan, an weight problems professional on the Massachusetts General Hospital, mentioned that the drug’s impact “appears to be significantly better than any other anti-obesity medication that is currently available in the U.S.” The outcomes, he added, are “very impressive.”

Dr. Kaplan who consults for a dozen pharmaceutical firms, together with Eli Lilly, mentioned he was not concerned within the new trial or within the improvement of this drug.

On common, contributors within the examine weighed 231 kilos on the outset and had a physique mass index, or B.M.I. — a generally used measure of weight problems — of 38. (Obesity is outlined as a B.M.I. of 30 and better.)

At the top of the examine, these taking the upper doses of the Eli Lilly drug, known as tirzepatide, weighed about 180 kilos and had a B.M.I. just under 30, on common. The outcomes far exceed these normally seen in trials of weight-loss medicines and are normally seen solely in surgical sufferers.

Some trial contributors misplaced sufficient weight to fall into the conventional vary, mentioned Dr. Louis J. Aronne, director of the excellent weight management heart at Weill Cornell Medicine, who labored with Eli Lilly because the examine’s principal investigator.

Most of the individuals within the trial didn’t qualify for bariatric surgical procedure, which is reserved for individuals with a B.M.I. over 40, or these with a B.M.I. from 35 to 40 with sleep apnea or Type 2 diabetes. The danger of creating diabetes is many occasions greater for individuals with weight problems than for individuals with out it.

An Eli Lilly spokeswoman mentioned the corporate didn’t have a public timeline for in search of approval of the drug with the Food and Drug Administration.

Because weight problems is a power medical situation, sufferers would want to take tirzepatide for a lifetime, as they do for blood stress or ldl cholesterol medication, for instance.

Dr. Robert F. Kushner, an weight problems professional at Northwestern University’s Feinberg School of Medicine and a paid advisor to Novo Nordisk, mentioned the brand new drug together with an identical however much less efficient one by Novo Nordisk, can shut a so-called therapy hole.

Diet and train, mixed with earlier weight problems medication, normally yield maybe a ten p.c weight reduction in sufferers. That is sufficient to enhance well being, however not almost sufficient to make an enormous distinction within the lives of peoples who’re overweight.

The solely different therapy is bariatric surgical procedure, which may end up in substantial weight reduction. But many individuals are ineligible or just don’t need the surgical procedure.

With the Eli Lilly drug and Novo Nordisk’s semaglutide, which was just lately permitted, “we really are on the cusp of a new way of treatment,” Dr. Kushner mentioned.

But costs could also be a barrier. Insurers typically won’t pay for weight reduction medication. The Novo Nordisk drug, whose model title is Wegovy, has an inventory worth of $1,349.02 monthly.

Experts fear that tirzepatide, if permitted, may carry a worth in the identical vary. Many individuals who might most profit from weight reduction could also be unable to afford such costly medication.

The Eli Lilly examine lasted 72 weeks and concerned 2,539 contributors. Many certified as overweight, whereas others have been chubby but in addition had such danger components as hypertension, excessive levels of cholesterol, heart problems or obstructive sleep apnea.

They have been divided into 4 teams. All obtained food plan counseling to scale back their calorie consumption by about 500 a day.

One group was randomly assigned to take a placebo, whereas the opposite three obtained doses of tirzepatide starting from 5 milligrams to fifteen milligrams. Patients injected themselves with the drug as soon as every week.

Those taking the very best dose misplaced probably the most weight, the investigators discovered. Participants taking a placebo misplaced 2.4 p.c of their weight, a mean of 5 kilos, typical for a food plan examine.

Dr. Nadia Ahmad, senior medical director of Eli Lilly’s weight problems program, mentioned that seeing the outcomes was an emotional second for her.

“I don’t think I ever imagined we could reach this degree of weight loss with a medicine,” she mentioned. “We only got this far with surgery.”

For a long time, people who find themselves chubby or have weight problems have been informed that fixing the issue was as much as them. Diet and train have been the prescriptions, they usually merely didn’t work for many individuals. Most tried food plan after food plan, solely to regain any weight they misplaced.

Last 12 months, the scenario started to vary when Novo Nordisk obtained approval from the Food and Drug Administration to market semaglutide. The drug can elicit a 15 p.c to 17 p.c weight reduction in individuals with weight problems.

The medicines are amongst a brand new class of medicine known as incretins, that are naturally occurring hormones that gradual abdomen emptying, regulate insulin and reduce urge for food. The unwanted effects embrace nausea, vomiting and diarrhea. But most sufferers tolerate or are usually not bothered by these results.

Incretins increase the bar for the form of weight reduction potential with medication. But additionally they pose troublesome questions on whether or not bariatric surgical procedure is turning into a relic of the previous. Already there are new variations of incretins in improvement that is perhaps much more highly effective than the Eli Lilly drug.

Even with out them, Dr. Aronne mentioned, the reductions noticed with the Eli Lilly drug are “squarely in the range of surgical weight loss.”

Some sufferers who’ve had bariatric surgical procedure describe combined outcomes. Sarah Bramblette, a board member of the Obesity Action Coalition, had bariatric surgical procedure solely to regain the burden.

Now 44, she weighed 500 kilos when she had the operation 20 years in the past, which enabled her to get all the way down to 250 kilos. Over the years, although, her weight crept again as much as 490 kilos. She wanted coronary heart surgical procedure however was too heavy for the working desk. Diets — and he or she has tried them repeatedly — didn’t assist.

Novo Nordisk’s semaglutide enabled her to get all the way down to 430 kilos. Now, Ms. Bramblette mentioned, she wish to strive the Eli Lilly drug if it turns into obtainable.

“Trust me, I would not choose to be this size,” Ms. Bramblette mentioned. “I need to lose weight.”