Pharmaceutical company Eli Lilly last week discovered the latest data from a phase III trial of his experimental drug for type 2 diabetes and obesity, tirzepatide: People who took the drug lost up to 22% of their body weight and achieved far greater weight loss on average than the placebo group. The findings, though preliminary, suggest that tirzepatide could become the second major drug in the new era of obesity treatment, provided patients can really afford it.
The SURMOUNT-1 study included more than 2,500 patients who were overweight (defined as having a body mass index of 25 to 30) or obese (BMI above 30), and also had a condition that may be related to their weight, with the exception of diabetes. These patients were randomized to receive either placebo or one of three different doses of tirzepatide, delivered weekly by subcutaneous injection. In addition to treatment, each group was advised to go on a diet with reduced calorie intake and increased physical activity. The trial was conducted in the United States, Argentina, Brazil, China, India, Japan, Mexico, Russia and Taiwan.
Each group lost weight on average over 72 weeks, but the loss was much higher in the groups receiving tirzepatide. Those given the 5 milligram dose lost an average of 15% of their body weight; those at the 10 milligram dose lost 19.5% and those at the 15 milligram dose lost 20.9%, compared with a weight loss of 3.1% in the placebo group. When people who left the study early were taken into account, the study’s researchers estimated that people at the highest dose lost an average of 22% of their body weight, or about 50 pounds. Side effects were generally mild to moderate, but included nausea, vomiting, and diarrhea, which often occurred early as doses escalated in humans.
The findings have yet to be published in a peer-reviewed journal, so they should be taken with some caution. But the numbers seen here, assuming they are accurate, are simply unprecedented for the drug, says Samantha Harris, an endocrinologist at the Scripps Clinic that focuses on weight control and diabetes care.
“The ability to lose 15%, 20% or 25% of total body weight with medication is amazing, as such results have usually only been seen in patients who have undergone bariatric surgery,” Harris said in an email to Gizmod.
Last June, Novo Nordisk Wegovy won approval from the Food and Drug Administration for the treatment of obesity. Wegovy is a higher dose version of semaglutide, the same active ingredient used in its diabetes medications Ozempic and Rybelsus. Key trials for Wegovy showed that patients lost an average of 15% of their body weight – numbers that now correspond to or exceed tirzepatide.
Both semagglutide and tirzepatide work by essentially increasing levels of a hormone called GLP-1. But tirzepatide also increases levels of another hormone called GIP (glucose-dependent insulin tropical polypeptide). These incretins, as they are known, play a key role in regulating our metabolism and hunger. The combination of GLP-1 and GIP activity observed with tirzepatide could very well explain its superiority over semaglutide in studies to date, Harris said.
They have been shown to be incretin-based drugs valuable and safe treatments for type 2 diabetes for more than a decade, especially through increased production of insulin that helps keep blood sugar under control. But the continued success we see with these drugs outside of diabetes could be just the beginning, according to Michael Albert, an obesity specialist. Patients who take them also have showed improvements in cardiovascular health, for example, and some studies have even suggest they could provide a protective effect against dementia, although more research will be needed there to confirm all the benefits.
“I think we see a new era of therapy here. And these drugs will really make a significant difference in our fight against many of these chronic diseases that we have really struggled to overcome, ”Albert told Gizmod by phone.
As promising as these drugs may be, some critics have questionable the inherent value of obesity treatments, especially given their overall uneven record. Another burning issue, even for those who want to take these treatments, is accessibility. Wegovy’s out-of-pocket price is about $ 1,400 a month, and neither he nor other obesity treatments are eligible to cover basic Medicare plans. Many private insurers also refused to cover Wegovy. And since last year, Novo Nordisk has been dealing with a shortage of production, which has made it even more difficult for new patients to purchase medicine.
“The drugs themselves seem to be excellent, but Wegovy is expensive, and others are likely to be,” said Stephan Guyenet, a neuroscience researcher, author and editor of reviews at Frontiers in Nutrition, in an email to Gizmodo. “This is especially true in the US, where Wegovy costs about four times more than in other countries. So the main issue is access. ”
Novo Nordisk has He said that its factory problems will be cleared up by the second half of the year. Based on earlier test results, Eli Lilly already had it filed tirzepatide for FDA approval as a drug for diabetes late last year, and a decision on that indication is expected before the end of the second trimester. Eli Lilly will almost certainly submit the drug for approval and as a drug for obesity, although it seems that a clear schedule has not yet been set.
Assuming that the results of tirzepatide are justified, we will probably have two newer drugs available next year and others, even more effective therapy could follow over the next decade. This competition could lower prices or at least strengthen their broad coverage.
“My only extreme concern is: what does access to these drugs look like? Will they be covered in the long run? ” said Albert. “If we can achieve the part of the coverage, which I think will come with more momentum around data reporting, the sky is the limit. And I think there is real hope on the horizon for patients who will benefit from these treatments. ”
One way or another, these drugs are likely to turn conversation into a conversation that is less focused on personal choices and more on the metabolic underpinnings of obesity.