麻豆传媒

Tirzepatide (Zepbound) was effective at reducing body weight in Chinese adults with lower cutoffs for overweight or obesity, the SURMOUNT-CN trial reported.

In the study of 210 adults without diabetes, participants on tirzepatide and lifestyle intervention lost an average of 15.1% (95% CI -18.2 to -12.1) more body weight with the highest dose compared with placebo after 52 weeks, Xiaoying Li, MD, of Zhongshan Hospital at Fudan University in Shanghai, China, and colleagues detailed in .

Most patients shed at least 5% of their body weight -- the threshold for being clinically meaningful -- on both tirzepatide doses tested (87.7% on 10 mg and 85.8% on 15 mg), compared with 29.3% of the placebo group. Body weight dropped by 27.1, 35.5, and 4.6 lb (12.3, 16.1, and 2.1 kg), respectively.

"This is the first study to assess tirzepatide for weight management in Chinese participants, who account for the largest number of individuals living with obesity and overweight worldwide," Li's group wrote.

The findings were similar to those of the pivotal SURMOUNT trials that supported tirzepatide's approval for a weight loss indication in November 2023. The GIP/GLP-1 receptor agonist was first approved in May 2022 for treating type 2 diabetes. In SURMOUNT-1, which included people with overweight or obesity without diabetes, people taking 15 mg of the once-weekly injectable lost an average 22.5% of body weight -- representing a mean loss of 52 lb (24 kg) -- over 72 weeks.

That trial enrolled some participants from China, Japan, and Taiwan, but only 10.9% of the cohort was Asian. For entry criteria, it also used traditional BMI minimum thresholds of 30 for obesity and 27 for overweight paired with at least one weight-related comorbidity.

used lower BMI thresholds reflective of the Asian population: a BMI of 28 or at least 24 with one or more weight-related comorbidities, excluding diabetes. Half of participants were female, average age was 36.1, and baseline body weight and BMI were 202.4 lb (91.8 kg) and 32.3, respectively.

"Using a lower BMI cutoff was appropriate given the well-established finding that individuals of East Asian ancestry develop cardiometabolic complications from overweight or obesity at a lower BMI compared with individuals of European ancestry," noted Frank Qian, MD, MPH, of Boston University, and Frank Hu, MD, PhD, of Harvard T.H. Chan School of Public Health in Boston, writing in an .

But only 8% of the cohort fell into overweight BMI category between 24 and 27.9 with a weight-related comorbidity, which Qian and Hu argued was "too small to draw conclusions regarding the efficacy of tirzepatide in this lower BMI category."

These lower BMI thresholds for Asian patients are already utilized for bariatric surgery. While metabolic or bariatric surgery is recommended for most patients with a BMI of 35 or more, advise Asian patients with a BMI of 27.5 or higher be offered surgery.

"Because of cost, limited access to health care facilities with expertise in bariatric surgery, preference for nonsurgical interventions, or other factors, few eligible people opt for metabolic surgery, making pharmacotherapy an important alternative or adjunct therapy for weight loss," commented Weiping Jia, MD, PhD, of Shanghai Jiao Tong University School of Medicine, and co-authors in .

The adverse event profile was generally similar in this Chinese cohort as has been previously reported, with gastrointestinal events leading as the most frequently reported. Diarrhea, nausea, and vomiting were the most common, but the majority of events were mild to moderate in severity and occurred primarily during the dose escalation period. Treatment discontinuation due to adverse events occurred in 7.7% and 2.9% of the 15- and 10-mg tirzepatide groups versus 1.4% of placebo-group patients.

The dose escalation period consisted of an initial dose of 2.5 once-weekly, which increased by 2.5 mg every 4 weeks until the maintenance dose was reached between weeks 12 and 20. Tirzepatide was paired with lifestyle intervention which included lifestyle counseling aiming for a daily 500 kcal deficit and 150 minutes of weekly physical activity.

Body weight change from baseline was (P<0.001 for both tirzepatide groups vs placebo):

• -17.5% with 15-mg tirzepatide (95% CI -19.7 to -15.3)
• -13.6% with 10-mg tirzepatide (95% CI -15.8 to -11.4)
• -2.3% with placebo (95% CI -4.4 to -0.3)

In addition to weight loss, there were significant reductions in waist circumference by week 52 of 14.5, 11.4, and 2.6 cm, respectively. Cardiometabolic factors like fasting glucose, insulin, very low-density lipoprotein cholesterol, triglycerides, and systolic and diastolic blood pressure all also significantly improved with tirzepatide compared with placebo.

These positive findings may also apply to other Asian populations too, "where BMI of 23 and 27.5 are defined by the World Health Organization as trigger points in Asian individuals for increased and high risk states calling for public health action," Jia's group said.

They advocated for more study "to verify the effects of tirzepatide in other Asian populations and particular attention should be paid to the effect of these agents on central obesity or visceral adiposity."