New diabetes drug looks poised to take weight-loss market by storm

The new drug, tirzepatide, helped people with type 2 diabetes who were overweight or obese lose up to 34 pounds over 17 months

tirzepatide, Mounjaro, Ozempic, Wegovy, semaglutide
Obesity affects more than four in 10 American adults and is linked to dozens of diseases that can lead to disability or death | Representational image by on Freepik

After Ozempic and Wegovy, an even more powerful obesity medicine is poised to take over the American market. The first two drugs gained much popularity after being touted by celebrities and on TikTok for their ability to shave off quite a few pounds.

The new drug, tirzepatide, sold under the brand name Mounjaro by Eli Lilly and Co., was approved to treat type 2 diabetes. It helped people with the disease who were overweight or obese lose up to 16 per cent of their body weight, or more than 34 pounds, over nearly 17 months, news agency AP reported the company as saying on Thursday (April 27).

The late-stage study of the drug added to earlier evidence that similar participants without diabetes lost up to 22 per cent of their body weight over that period with weekly injections of the drug. For a typical patient on the highest dose, that meant shedding more than 50 pounds.

Never-seen-before results

“Having diabetes makes it notoriously difficult to lose weight, which means the recent results are especially significant. We have not seen this degree of weight reduction,” Dr Nadia Ahmad, Lilly’s medical director of obesity clinical development, told AP.

Based on the new results, which have not yet been published in full, company officials said they will finalise an application to the US Food and Drug Administration for fast-track approval to sell tirzepatide for chronic weight management.

Also read: Obesity can impair learning, memory: Study

A decision could come later this year. A company spokeswoman would not confirm whether the drug would be marketed for weight loss in the US under a different brand name.

If approved for weight loss, tirzepatide could become the most effective drug to date in an arsenal of medicines that are transforming the treatment of obesity, which affects more than four in 10 American adults and is linked to dozens of diseases that can lead to disability or death.

“If everybody who had obesity in this country lost 20 per cent of their body weight, we would be taking patients off all of these medications for reflux, for diabetes, for hypertension,” said Dr Caroline Apovian, a director of the Centre for Weight Management and Wellness at Brigham and Women’s Hospital. “We would not be sending patients for stent replacement,” she added.

May outpace semaglutide

Industry analysts predict that tirzepatide could become one of the top-selling drugs ever, with annual sales topping $50 billion. It is expected to outpace Novo Nordisk’s Ozempic and Wegovy. While the former is a diabetes drug used so commonly to shed pounds that comedian Jimmy Kimmel joked about it at the Oscars, Wegovy is another version of the drug called semaglutide, which was approved for weight loss in 2021.

Together, those drugs made nearly USD 10 billion in 2022, with prescriptions continuing to soar, company reports show. In separate trials, tirzepatide has resulted in greater weight loss than semaglutide, whose users shed about 15 per cent of their body weight over 16 months. A head-to-head trial comparing the two drugs has been planned.

Also read: Obesity leads to more cases of cancer than smoking

Mounjaro was first approved to treat diabetes last year. Since then, thousands of patients have obtained the drug from doctors and telehealth providers who prescribed it “off-label” to help them slim down.

In California, Matthew Barlow, a 48-year-old health technology executive, said he has lost more than 100 pounds since November by using Mounjaro and changing his diet. “Psychologically, you don’t want to eat,” said Barlow. “Now I can eat two bites of a dessert and be satisfied.”

How obesity drugs work

Rather than relying solely on diet, exercise, and willpower to reduce weight, tirzepatide and other new drugs target the digestive and chemical pathways that underlie obesity, suppressing appetite and blunting cravings for food.

They have entirely changed the landscape, said Dr Amy Rothberg, a University of Michigan endocrinologist who directs a virtual weight-loss and diabetes programme.

Research shows that with diet and exercise alone, about a third of people will lose 5 per cent or more of their body weight, said Dr Louis Aronne, director of the Comprehensive Weight Control Centre at Weill Cornell Medicine.

In the latest tirzepatide trial, more than 86 per cent of patients using the highest dose of the drug lost at least 5 per cent of their body weight. More than half on that dose helped patients lose at least 15 per cent, the company said.

Also read: Obesity goes up in India, fertility rate dips: National Family Health Survey

The obesity medicines help overcome a biological mechanism that kicks in when people diet, triggering a coordinated effort by the body to prevent weight loss. That is a real physical phenomenon, Aronne said. There are several hormones that respond to reduced calorie intake.

Semaglutide, for instance, mimics a key gut hormone, known as GLP-1, that is activated after people eat, boosting the release of insulin and slowing release of sugar from the liver. It delays digestion and reduces appetite, making people feel full longer.

Tirzepatide is the first drug that uses the action of two hormones, GLP-1 and GIP, for greater effects. It also targets the chemical signals sent from the gut to the brain, curbing cravings and thoughts of food.

The downsides

Though the drugs appear safe, they can cause side effects, some serious. Most common reactions include diarrhoea, nausea, vomiting, constipation, and stomach ache. Some users have developed pancreatitis or inflammation of the pancreas; others have had gallbladder problems. Mounjaro’s product description warns that it could cause thyroid tumours, including cancer.

There are other downsides, too: Versions of semaglutide have been on the market for several years, but the long-term effects of taking drugs that override human metabolism are not yet clear. Early evidence suggests that when people stop taking the medications, they gain the weight back.

Plus, the medications are expensive and, in recent months, hard to get because of intermittent shortages. Wegovy is priced at about $1,300 a month. Mounjaro used for diabetes starts at about USD 1,000 per month.

Also read: Weight loss may help cut heart attack, stroke risk in diabetics: Cambridge study

Apovian said that only about 20 to 30 per cent of patients with private insurance in her practice find the medications are covered. Some insurers who previously paid for the drugs are enacting new rules, requiring six months of documented lifestyle changes or a certain amount of weight loss for continued coverage. Medicare is largely prohibited from paying for weight-loss drugs, though there have been efforts by drugmakers and advocates for Congress to change that.

Still, experts say that the striking effects of tirzepatide along with Ozempic, Wegovy and other drugs underscore that losing weight is not merely a matter of willpower. Like high blood pressure, which affects about half of US adults and is managed with medication, obesity should be viewed as a chronic disease, not a character flaw, Aronne emphasised.

It remains to be seen what effect new drug treatments will have on pervasive bias against people with obesity, said Rebecca Puhl, a professor in the Rudd Centre for Food Policy and Health, who studies weight stigma. US culture has deep-rooted beliefs about body weight and physical appearance that are hard to change, she said.

Weight stigma could persist or worsen if taking medication is equated with taking the easy way out or not trying hard enough, she said.

(With agency inputs)