Newly Approved Diabetes Drug Delivers Record-Breaking Weight Loss in Clinical Trial

A woman holding the belt loop on her jeans. Illustration - Shutterstock

A type 2 diabetes (T2D) drug recently approved by the Food and Drugs Administration (FDA) has reportedly reduced more than 20 percent of weight in obese individuals by administering the drug once every week.

The SURMOUNT-1 study, a Phase 3 trial led by Yale University researchers testing the efficacy and safety of tirzepatide, found that obese participants who took the drug at a dosage of 15 mg concentration by the 72nd week had a record-breaking weight reduction of 22.5 percent on average.

The drug activates GLP-1 and GIP; GLP-1 increases production of insulin to bring down elevated blood sugars and GIP increases insulin production whilst also inhibiting gastric motility, meaning that food will stay inside the digestive system for longer.

Traditional weight loss drugs reduce weight by 5 to 10 percent. Whereas tirzepatide’s over 20 percent in users is comparable to bariatric surgery; widely believed to be the most effective weight loss method as surgeries usually lead to a weight reduction of 25 to 30 percent.

More than 2,500 obese individuals participated in the study and were allocated to either placebos, tirzepatide at 5 mg, 10 mg, or 15 mg for 72 weeks.

Since a weight loss of 5 percent is considered clinically significant, weight loss across all dosage groups were significant. All three doses of the drug resulted in substantial loss and sustained body weight reduction, with patients on 5 mg of tirzepatide seeing a reduction of 16 percent and 21.4 percent for the group on 10 mg.

A weight loss of 5 percent was achieved in 89 percent of patients on the lower dosage and 96 percent on the higher doses, as compared to 28 percent of patients in the placebo cohort.

“An effective power of greater than 90 percent” demonstrates “the superiority of tirzepatide,” wrote the authors.

“It is remarkable that in this trial, the majority of participants receiving 10-mg or 15-mg doses of tirzepatide achieved this benchmark.”

The researchers observed an over 5 percent weight reduction across two primary endpoints; the baseline weight also known as the set point—the weight the body will always try to return to—as well as actual body weight.

Side effects observed were primarily gastrointestinal, and included nausea, vomiting, and diarrhea; and mainly occurred when dosage was increased for participants, also known as the dose-escalation period.

However, clinical studies also indicated that some participants reported cases of pancreatitis, hypoglycemia, severe allergic reactions, and gall bladder disease.

Participants exposed to the drug all started at 2.5 mg in the first week, and had their dosage increased by 2.5 mg every four weeks during dose-escalation until the dosage limit of their group is reached.

Lifestyle intervention included regular lifestyle counseling sessions, delivered by a dietitian or a qualified health care professional. This is to help the participants adhere to healthy, balanced meals, achieving a deficit of 500 calories per day, and at least 150 minutes of physical activity per week.

The news comes as tirzepatide, branded as Mounjaro, was approved by the FDA on March 13, 2022, as a drug for diabetes, but has not yet been approved as a weight-loss treatment.

A report by Medscape stated that Lilly, the company marketing the drug, will price four weekly doses of the drug at $974.33 regardless of dose size, a cost that adds up to about $12,666 per year.

The findings of the study were presented at the American Diabetes Association Scientific Sessions in New Orleans on June 4.