Eli Lilly's experimental obesity drug combination has delivered weight loss of up to 23.3% in a mid-stage trial, adding to pressure on rival Novo Nordisk, according to Citi.
The treatment, called EloraTZP, pairs Lilly's new drug eloralintide with tirzepatide, the active ingredient in its blockbuster Mounjaro.
Together they mimic three gut hormones, amylin, GIP and GLP-1, which help control appetite and blood sugar.
The phase IIb trial, presented at the European Association for the Study of Diabetes (EASD) meeting, tested the drug in overweight or obese patients with type 2 diabetes.
Beats existing rivals
After 48 weeks, patients lost up to 23.3% of their body weight, compared with 14.8% on the top dose of tirzepatide alone.
HbA1c, a measure of long-term blood sugar, fell by up to 2.9%, against 2.4% for tirzepatide.
Citi said the weight loss looked competitive with Novo's CagriSema, which achieved 15.7% over 68 weeks in a similar group of patients.
It also compared well with Lilly's own retatrutide, at 20.8% over 80 weeks.
Dropouts a concern
The weak spot was tolerability.
Between 10.8% and 27% of patients quit the trial because of side effects, compared with 2.9% on tirzepatide and 8.4% on CagriSema.
Most of those dropouts came while doses were being increased.
Lilly plans a gentler dosing schedule when it starts phase III trials by the end of 2026, which could reduce the problem.
Citi said the data was another reminder of how crowded the obesity market is becoming, and of the pressure on Novo.
