Louis J. Aronne, MD, Weill Cornell Medicine, New York, presented findings from a prespecified analysis of BMI subgroups (oral abstract 110).
The four BMI subgroups were:
- ≥ 27 to < 30 kg/m2 (overweight), mean initial weight 178 pounds, mean weight reduction 29-30 pounds
- ≥ 30 to < 35 kg/m2 (class 1 obesity), mean initial weight 198 pounds, mean weight reduction 33-43 pounds
- 35 to < 40 kg/m2 (class 2 obesity), mean initial weight 228 pounds, mean reduction 34-56 pounds
- 40 kg/m2 (class 3 obesity), mean initial weight 280 pounds, mean weight reduction 44-64 pounds
Patients with an initial BMI of ≥ 35 to < 40 kg/m2 who received the 15-mg/week dose of tirzepatide had the greatest weight loss, at 24.5%, which is approximately what is seen with bariatric surgeries such as sleeve gastrectomy (25%).
The proportion of patients reaching ≥ 5% weight reduction was approximately 90% in all weight categories. “These numbers are unprecedented,” said Dr. Aronne.
In addition, overall, 73%-90% of patients receiving the 5- to 15-mg doses of tirzepatide achieved ≥ 10% body weight reduction, and “something we never thought we would see” is that 50%-78% of the patients receiving the drug lost 15% or more of their body weight.
In reply to an audience question, Dr. Aronne said it would take further study to determine who would respond well to tirzepatide.
And in reply to another question about whether it would make sense to treat to a target of a normal BMI, he said: “I think we are getting there.”
Patients in the 27- to 30-kg/m2 BMI category lost about the same amount of weight at a 5-mg dose as at a higher dose, suggesting they should stick to the lower dose, which would likely also have fewer side effects, he noted.
Number of comorbidities
Comorbidities in SURMOUNT-1 included hypertension, dyslipidemia, obstructive sleep apnea, atherosclerotic cardiovascular disease, osteoarthritis, anxiety/depression, polycystic ovary syndrome, nonalcoholic fatty liver disease, and asthma/chronic obstructive pulmonary disease. Of the patients with no comorbidities, 32.6% had prediabetes (oral abstract 111).
Sriram Machineni, MD, University of North Carolina at Chapel Hill, noted that obesity is associated with a significantly increased risk of clustering of at least two obesity-related complications, but little is known about how this affects outcomes.
The patients in SURMOUNT-1 were classified into three groups based on number of comorbidities:
- Zero comorbidities, 37% of patients: baseline mean age of 39, mean duration of obesity of 12 years, 29% men
- One comorbidity, 27% of patients: baseline mean age of 44, mean duration of obesity of 14 years, 31% men
- Two or more comorbidities, 36% of patients: baseline mean age of 52, duration of obesity 17 years, 37% men
Regardless of the number of comorbidities, all doses of tirzepatide resulted in a greater reduction in body weight compared with placebo.
Quality of life
Jiat Ling Poon, MD, an employee of Eli Lilly, presented findings from patient-reported replies to questionnaires including Impact of Weight on Quality of Life–Lite (IWQOL-Lite), which assesses physical and psychosocial health, and the Short Form–36 Health Survey, which assesses physical functioning, bodily pain, vitality, role-emotional, role-physical, general health, social functioning, and mental health (oral abstract 112).
Tirzepatide at all doses resulted in significantly greater improvements in patient-reported outcomes compared with placebo.
Meanwhile, the phase 3 SURMOUNT-2 clinical trial of tirzepatide for weight loss in patients with type 2 diabetes is projected to be completed in April 2023.
The studies were funded by Eli Lilly.
A version of this article first appeared on Medscape.com.