The US Food and Drug Administration (FDA) has approved Eli Lilly’s new obesity treatment Zepbound (tirzepatide) for ‘chronic weight management in adults who are obese or overweight and have at least one weight-related health condition’ – such as high blood pressure, high cholesterol or type 2 diabetes.
The GLP-1 drug Zepbound shares the same active ingredient as Mounjaro, another drug made by Eli Lilly used to treat type 2 diabetes.
Over the past year the FDA has approved several weight-loss drugs: some like Wegovy (semaglutide) have been approved for weight loss; others like Mounjaro (tirzepatide) and Ozempic (semaglutide) are approved for helping with type 2 diabetes – but ‘are also being used off-label to assist with weight loss’, noted medicalnewstoday.com.
The FDA approval of Zepbound was based on the results of two phase 3 clinical trials (SURMOUNT-1 and SURMOUNT-2), where researchers reported that over 72 weeks participants who took the highest dose of Zepbound lost an average of 48 lbs, and those who took the lowest dose lost an average of 34 lbs.
The studies found that one in three participants taking Zepbound at the highest dose lost over 58 lbs or 25% of their body weight. The average starting weight for a study participant was 231 lbs (104.78 kgs).
Dr Lydia Alexander, president-elect of the US Obesity Medicine Association, explained Wegovy, Ozempic, Mounjaro and Zepbound are all types of hormone replacement therapy. She noted: ‘They replace hormones in our weight regulatory system that are deficient or resistant, causing weight dysregulation resulting in overweight and obesity.’
All four are glucagon-like peptide-1 (GLP-1) receptor agonists, which helps with blood sugar control. However, Zepbound also activates a second hormone receptor.
US bariatric surgeon Dr Jeffrey Kraft told medicalnewstoday.com: ‘Where Zepbound differs slightly is that it also imitates a second hormone, called GIP (glucose-dependent insulinotropic polypeptide), which, along with reducing appetite, may also improve how the body breaks down sugar.’
But he also warned: ‘All of these drugs have side effects which can include some very uncomfortable gastrointestinal symptoms.’
The FDA’s prescribing information for Zepbound notes the most common adverse reactions include nausea, diarrhea, vomiting, constipation, abdominal pain, indigestion, injection site reactions, fatigue, hypersensitivity reactions, eructation, hair loss, and gastroesophageal reflux disease.
